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Intermediate-Moisture Meat andDehydrated Meat

TZOU-CHI HUANG

National Pingtung University of Science and Technology, Pingtung, Taiwan

WAI-KIT NIP

University of Hawaii at Manoa, Honolulu, Hawaii

I. INTERMEDIATE-MOISTURE MEATS AND DEHYDRATED MEATSA. Hams and Meat ChunksB. Slabs, Sheets, and SlicesC. StripsD. PiecesE. Floss or ShredsF. PowderG. Sausages

II. STABILITY OF INTERMEDIATE-MOISTURE MEATSA. Microbial Stability and SafetyB. Chemical Stability

III. STRUCTURAL COMPONENTS OF MUSCLE TISSUE RESPONSIBLE FORPHYSICOCHEMICAL PROPERTIES OF INTERMEDIATE-MOISTURE MEATPRODUCTSA. Gross Meat Structure

IV. EFFECT OF HEATING ON PHYSICOCHEMICAL PROPERTY CHANGES DURINGINTERMEDIATE-MOISTURE MEAT PROCESSINGA. ProteinsB. Sausages

V. PARAMETERS CONTROLLING THE STABILITY OF INTERMEDIATE-MOISTUREMEATSA. HeatingB. SaltC. Sucrose

Copyright © 2001 by Marcel Dekker, Inc. All Rights Reserved.

D. ChemicalsE. Intact Muscle IM MeatF. SausagesG. Innovative Water Activity Control Technology

VI. CONCLUSIONS

REFERENCES

I. INTERMEDIATE-MOISTURE MEATS AND DEHYDRATED MEATS

Intermediate-moisture (IM) meat contains 15% to 50% moisture, and dried meat productscontain even less moisture. They have a water activity (aw) value of 0.60 to 0.92. IM meatproducts are shelf-stable without refrigeration or thermal processing, and some can be eatenraw without rehydration or cooking. These dehydrated meat products usually are resistantto bacterial spoilage because of their low water activity and fairly high salt content. Someare fairly tough, with poor texture. However, some are highly palatable and are even con-sidered delicacies. Freeze-dried meat products are very porous in nature and can be rehy-drated to almost the original shape. Intermediate moisture meats and dried meats can be cat-egorized into two groups: intact muscle–based product and the emulsion-type sausage.Each group can be further subcategorized by the form because many are similar productsproduced in different cultures. Table 1 is a summary of selected dried or intermediate-mois-ture meat products. Dehydrated and freeze-dried raw or cooked meats are resistant to bac-terial spoilage but have poor texture and are sometimes expensive to prepare, such asfreeze-dried meat products. This section will cover some of the traditional IM and driedmeat products and their production processes, as well as the production of freeze-driedmeat products.

A. Hams and Meat Chunks

This group of IM meat products usually are made by using chunks of meat with or withoutthe shank bone. Traditionally they are dry-cured or pickle-cured. The dry-curing process isespecially time consuming and labor intensive because the curing agents have to be rubbedonto the raw meat chunks, which are then turned a few times. Pickle-cured products alsohave to be turned a few times during the curing period. For dry- or pickle-cured products,enough time must be given for the curing ingredients to penetrate to the center of the chunkof meat. They are then washed or soaked occasionally to remove some of the salt. With ad-vances in technology, cured meats can now be produced by stitch-injection cure to savetime. The drying process can be accomplished usually in several days by smoking or heat-ing in a chamber. Some products are partially dried first, and the drying process is com-pleted by gradually evaporating the moisture from the chunk of meat in a cool environment.At the same time, fermentation can proceed to give the product a typical flavor. Some prod-ucts will take over 6 months to a year to produce. The dry cured hams of continental Eu-rope (such as French Bayonne ham, German Westphalian ham, and Italian Parma ham)continued to be produced in a traditional manner and have retained their original organolep-tic qualities.

1. Italian Parma Ham

The Parma ham is made from 1-year-old pigs weighing roughly 180 kg raised in the north-ern Italian region around Parma. The pigs must be fed exclusively on corn (maize), oats,

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and rinds from Parmesan cheese (1). After slaughter, the carcasses are deep-frozen for 24hr and are pared of outer fat into a drumstick shape, salted, seasoned, and frozen for 8 days.On the ninth day, they come out to the kneading bench for the first of 30 to 40 massages tosqueeze out the juice and tenderize the meat. They are salted again, put in deep freeze for18 days, hauled out into fresh air for a day or two, then have a 30-day chill at exactly thefreezing point, and spend 3 months in the drying chamber. Then they are scrubbed withwarm water, sandpapered to an attractive outer finish, and put into ventilated storage untiltime to sell. The total curing time lasts from 10 to 15 months.

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Table 1 Examples of Dried and Intermediate-Moisture Meat Products

Form/type Examples References

Ham (chunk) Parma ham (Italian) 1Westphalian ham (German) 1Scotch ham 1Old time Virginia ham (American) 1Virginia ham (Smithfield, American) 1Chinese ham 2–4Dried beef 5Bundlnerfleisch, Rohschinken, Coppa, Speck, 5–7

Bindenfleish (Swiss)Slab, sheet, slice Bacon 8

Charque (Brazilian) 9–11Beef jerky (American Indian) 12–14Tasajo (Cuban) 15Kilishi (Nigerian) 16–17Balanqu (African) 18Dendeng (Indonesian) 19–22Spiced beef slices (Malaysian, Chinese) 3,20,21Ruogan, ruopu (Chinese) 3Shafu (Chinese) 2,3

Strip Jirge (African) 18Dried beef cecina (Spanish), cecina (Mexican) 23–24Biltong (African) 14,18,25Pemmican (American Indian) 26Ndariko (African) 18Basterma/Patirma (Egyptian/Turkish) 27–28Chinese-style bacon 2

Pieces Tsire/Suya (African) 18Banda (African) 18Freeze-dried meat pieces 29–30

Floss Rou song (Chinese) 31–32Zousoon (Taiwanese) 33–34Sambal daging (Malaysian) 20

Powder Sharmoot (Sudanese) 35Sausage Bologna (Lebanon) 32

Salami, pepperoni, Genoa (Italian) 5Salchichon (Spanish) 36Cervelet (European) 37–38Lup cheong (Chinese) 2–3


2. German Westphalian Ham

Westphalian hams are sliced and eaten raw (1). They are prepared by rubbing the ham witha mixture of 16 lb (7.26 kg) of salt and 1 oz (28.4 g) of saltpeter per 100 lb (45.36 kg) ofpork. After being placed on shelves or stacked on concrete floors and allowed to cure for 2weeks, they are then placed in a 22% brine solution (90° pickle) and allowed to cure for 18more days. At the end of this period, they are taken out from the brine and packed one aboveanother in a cool, dry cellar for 4 weeks of ripening period. Then the hams are cleaned witha stiff brush in lukewarm water and allowed to soak in fresh water for 12 hours. They arethen ready for smoking. Only beechwood is used, with the exception of juniper twigs andberries constantly thrown on the fire. Beechwood sawdust is strewed over the fire in caseit becomes too hot. The smoking process continues for a period of 7 to 8 days.

3. Scotch Hams

Scotch hams are made from fresh-skinned and deboned hams; most of the fat is removed,after which they are given a mild cure according to a formula. The cured ham is then rolled,tied and placed in a cellulose casing but it is not smoked (1).

4. American Virginia Ham (old-time)

The animals used in the production of old-time Virginia ham were slaughtered when thepoints of the new moon were up. Fine table salt was rubbed into each ham in one long thor-ough rubbing (1). Then the hock end was packed with salt, and an extra layer of salt wasspread over the entire ham. They were packed in barrels and left to cure for several weeksin a dry, cool place. At the end of 7 weeks, the hams were rubbed with a mixture of NewOrleans molasses, brown sugar, black pepper, cayenne pepper, and saltpeter. These ingre-dients were mixed in the following amounts to be rubbed on 100 pounds (45.4 kg) of ham:1/2 lb (22.7 g) black pepper, 1 qt (0.951) of New Orleans molasses, 1 lb (45.4 g) of brownsugar, 1 oz (28.4 g) saltpeter, and 1 oz (28.4 g) cayenne pepper. The hams to be rubbed werebrushed of all visible salt and then rubbed with the mixture and left to lie in a cool room foranother 2 weeks. At the end of this second period, they were hung in the meat house withthe hocks hanging downward. They were not smoked but were allowed to age for another30 days.

5. Virginia Ham (Smithfield, Virginia)

Smithfield (Virginia) hams must be processed in Smithfield and come from hogs grown inthe peanut belt of Virginia and North Carolina (1). The hams are sprinkled with saltpeter,using 4 lb (1.81 kg) per 1,000 lb (454.6 kg) ham, and are then given a rubbing of fine salt.Three to five days later, they are given a second rubbing of salt and stacked in a curing roomto cure for one day per pound (454 gm) of ham. After the cure, they are washed and givena cool smoke (26.6° to 29.4°C) for 7 to 10 days, using hickory wood and smothering theblaze with applewood sawdust. After smoking, they are rubbed with pepper and hung in ag-ing rooms for a period of 7 to 18 months. The shrinkage from green weight is around 25%.The dryness and saltiness of the hams require the consumer to soak them for 24 hours andsimmer them 4 to 6 hours.

6. Chinese Ham

The production of Chinese-style ham is similar to the production of country-cured (drycured) hams in the United States and can be divided into three phases. First the curing pe-

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riod, during which the curing ingredients [a mixture of 8 lb (3.63 kg) salt, 3 lb (1.36 kg)sugar, and 3 oz (85 g) sodium nitrate] are rubbed on the ham surface. Approximately 1 1/4oz (35.5 g) of the curing mix is used per lb (454 g) of ham. The total amount of curing mixshould be applied at three intervals and this will allow more uniform salt penetration. Dur-ing this time, generally about 30 to 40 days depending on the size of the hams, the productsshould be maintained under refrigeration. During the second phase, hams are hung in thesmokehouse and are subject to a cool smoke but are not cooked. The smokehouse temper-ature is kept between 70°F (21°C) and 90°F (32.2°C) and the initial temperature of the hamusually is approximately 10°F (5.5°C) lower than the smokehouse temperature. The smokeis applied continuously for 2 to 3 days until the hams obtain amber or mahogany color. Af-ter smoking, the third phase, which is the aging process, begins. Hams are normally agedfor 6 to 9 months, and this is usually not accomplished under refrigeration. During this time,the full flavor characteristic of the ham develops, probably as a result of enzymatic reac-tions. To encourage enzymatic activity, hams are usually aged between 70° and 85°F (21and 29.4°C) (2–4).

7. Dried Beef

Dried beef is cured, dried, and sometimes smoked, but not cooked. It is low in moisture,containing 25% to 35%. Either the dry- or pickle-cure procedure can be used, althoughmost commercially produced dried beef is cured in pickle with salt, sugar, nitrate, and ni-trite. If the meat is dry-cured, 1 oz (28.4 g) of curing mix per pound (454 g) of meat shouldbe applied to the meat surface. The curing mix should be applied to the meat surface. If thepickle cure is used, the cure ingredients are dissolved in water, enough to cover the rawmeat. The length of cure depends on the size of cuts. Generally, muscles of the round—top,bottom, and knuckle—are used for manufacture of dried beef, but shoulder clods are alsoused. As a rule of thumb, dry- or pickle-cured meat should remain in cure of 2 to 3 days perpound (454 gm) of meat. After being removed from cure, the meat is rinsed with cold wa-ter and allowed to dry. When produced in a commercial establishment, the beef is gener-ally dried in a smokehouse for 2 to 3 days. Smokehouse temperatures range from 90° to100°F. Depending on the desires of the individual processor, smoke is applied during partof the drying period (5).

8. Swiss Bundlnerfleisch, Rohschinken, Coppa, and Speck

Bundnerfleish is prepared from the choice cuts of lean quarter beef. It is dry-salted with acuring period of 3 to 4 weeks, followed by a fermenting, drying and maturing period of 3to 4 months. During processing the total weight loss is about 40%. The final product hasapproximate 34% protein, 56% to 59% moisture, 4% to 6% fat, and 3% to 4% salt. The re-sultant products appear hard and mummified with most of their surface covered by a whitemold. Prior to consumption, this outer casing has to be trimmed off and the dark red innermeat is usually sliced very thinly and eaten raw. The pork products (Rohschinken, Coppa,and Speck) are prepared in a similar manner (5–7).

B. Slabs, Sheets, and Slices

Slab-type, sheets, or slices of IMM are produced in a similar manner. Meat is cut into slabs,sheets, or slices, cured for the appropriate periods, and dried by heating or smoking. How-ever, the water activity of the final products may be different because of cultural habits andconsumer preference.



1. Bacon

Bacon can be made by dry cure or pickle cure. In the case of dry cure bacon, a mixtureof curing ingredients is rubbed on all surfaces of the green bellies. Bellies are placed ina cooler to cure for 10 to 14 days before cooking and smoking. Most commercial baconis pickle-cured by the stitch-injection method. Bacon is usually cooked in the smoke-house according to a one-step or three-step cook schedule, reaching a final internal tem-peratures of 130° to 140°F (54.4° to 60°C). The bacon is then cooled to an internal tem-perature of 26° to 28°F (�2.2° to �3.3°C) before slicing and vacuum packaging. Baconis generally stored under refrigeration (8). Canadian bacon is made from the large mus-cle of pork loins, the strip or sirloin muscle. Wilshire bacon is made from selected hogswith special cutting procedures of the carcasses. This product is lightly matured and canbe smoked (8).

2. Jerked Beef [Charque (Spanish, South America), Jerkey (English) orXarque (Portuguese, Brazil)] (9–14)

Charque is a beef product that should not contain more than 45% moisture within the in-tramuscular portion and not more than 15% of mineral residue, with aw of 0.70 to 0.75.Manufacturing cuts for charque must be carefully prepared after deboning to produce mus-cle pieces of uniform thickness. Muscle blocks greater than 5 cm thick are not suitable.Where flank and rib pieces are used, little further work is required apart from small inci-sions to facilitate salt penetration. In the case of hind and forequarter cuts, more extensiveopening of the muscle blocks is necessary to ensure uniform salt penetration and consistentdrying times.

The wet salting or brining operations is carried out in pickled vats of approximately80 cm depth, of a size depending upon the capacity of the plant. The interior of the tankshould be lined with impermeable fine screened concrete or with high quality glazed tiles.A brine strength near 100° salometer as possible, but never less than 95, should be main-tained constantly during the wet salting stage. The brine should be maintained as far as pos-sible at 15° to 20°C. The immersed meat pieces are agitated vigorously, by the use of pad-dles, for a period of 50 minutes, after which they are removed from the tank. The meatacquires a blue tone during this phase of the processing. Dry salting is initiated, after themeat is removed from the brine tank, on a concrete floor covered with a 1 cm layer of salt.The floor should be slightly inclined, falling away into lateral channels to carry away themeat juice expressed during salting. The meat pieces are stacked into piles, separated fromeach other by layers of coarse marine salt (1 mm thick). The salt should be shoveled overthe meat as a fine shower from several directions to ensure even penetration into meat cutsand openings. The height and dimension of the pile are likely to be governed by the scaleof production but should not be allowed to exceed 1.5 meters for fear of exaggerating thepressure on the lower meat layers, thus causing excessive weight loss. Each pile when com-pleted should be capped with a 2 cm covering of salt. The pile is restacked after 8 hours inorder to equalize pressure throughout. Thus, the uppermost pieces are repositioned on thebottom of the new piles. As in the initial salting step, thick layers of coarse salt are placedbetween each successive meat layer and also on the top of the pile. The meat remains in thesecond pile for a period of 16 hours before being repositioned into its original order. Thepiles are remade every 24 hours in order to ensure even salt penetration and water loss andmicrobial contamination. The number of tumbling varies according to pile size and weatherconditions but should be 4 to 5 days.

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Before initiating drying, the meat pieces are subject to a rapid washing with acidifiedwater (pH �5.5) to remove excess salt adhering to the surface. If weather conditions are fa-vorable, charque is usually dried directly in the sun on wooden rails (varales) positionedparallel in runs oriented north-south. This orientation permits an even solar coverage. Thedistances between these runs should be sufficient to allow movement of barrows used totransport the meat from the washing to the open drying area. The meat pieces are extendedover the rails with the muscle layer uppermost in order to limit undesirable changes to thefat caused by direct exposure to the solar rays. The initial drying, directly in the sun, is lim-ited to a maximum period of 4 to 6 hours. This period of exposure may be subsequentlylengthened to a maximum of 8 hours. Temperatures in excess of 40°C on the meat surfaceshould be avoided. The meat pieces are exposed to the sun each day over a period of 4 to 5days. After each period of exposure, the pieces are recollected, stacked in piles on concreteplinths and covered with an impermeable cloth or tarpaulin to protect them against rain andwind and to hold the heat absorbed by the sun. The top of the pile is usually built with acrown to facilitate purging and, in the case of rain, water will run off.

During times of the year where there is constant rain or cloud cover, or in regionswhere weather patterns are uncertain, the process of winter pillage is used. Meat pieces arestacked in piles up to 3 meters in height on special concrete plinths immediately after thethird or fourth tumbling and without prior washing. Piles should be built with a 10% slopefrom center to sides to allow free draining. The piles may be erected in a covered area ad-jacent to the dry salting room or in a refrigerated store, if this is available. Fine salt (lessthan 2 mm grain size) should be positioned between layers at the moment of putting intopiles. While piles are kept at ambient temperatures, they must be carefully maintained toobviate microbial spoilage. This is achieved by covering the whole pile with a thick layerof marine salt, treated with sodium hypochlorite solution (0.4%) up to a thickness of 20 to30 cm. Alternately, salted offals such as lungs, hearts, and kidneys may be used to coverthe meat pieces. Air penetration into the pile should be prevented as far as possible. A heavyhessian cover moistened with 50% sterilized brine is usually employed to prevent desicca-tion of the upper meat layers. This is tied down using strong cord. The fermentation pro-cess takes place under strictly anaerobic conditions. The piles may be maintained in thisstate for up to 4 months, after which the meat is washed using acidified water, and dried inthe sun according to procedures described earlier. Winter-pillaged charque is usually sub-ject to 2- to 3-day sun drying.

3. Cuban Tasajo

Tasajo is a traditional Cuban intermediate-moisture product made from beef sheets that aresoaked in brine, drained, rubbed in salt and layered with salt in vats for several days,washed, and sun-dried (15).

4. Nigerian Kilishi

Kilishi is a traditional means of preserving meat used by the Fulani and Hausen herdsmen.Kilishi is mainly prepared from the hindquarters of beef carcasses, but mutton and goatmeat are also sometimes used. From the choice, lean cuts, thin sheets of fresh meat of about17 to 20 mm thickness and an average length of 140 cm are cut manually. These are firstsun-dried at 30° to 36°C, and 21% to 26.5% relative humidity on a raised bed for 4 hr. Thenthe slices are immersed in a slurry of groundnut cake powder and seasonings for one hr andredried in the sun under similar conditions for 2 to 3 hr to a low moisture content (20% to25%). Depending on the quantity of product and the climatic conditions, this drying may



take from 5 to 12 hr or even more. The product is finally roasted over a fire for 3 to 5 minwith final moisture of 12% to 15%. There are some concerns about the carcinogenic poly-cyclic aromatic hydrocarbons (PAH) in these smoked products (16,17).

5. African Balanqu

Balanqu may be defined as boneless slabs of lean/organ meat seasoned with salt, spices,groundnut flour, and oil, and roasted over a low-burning/glowing smokeless fire. It is pre-pared mostly from beef, but also occasionally from mutton and goat meat. The meat isboned and cut into chunks that are sliced with a curved knife into slabs not less than 1 cmthick, most commonly 4-6 cm or more. The meat slabs are dusted on both surfaces with aseasoning mixture of salt, spices, groundnut flour, and oil, and then placed on a wire meshover an oven of low-burning/glowing smokeless fire to roast slowly until done. Roastingtakes 30 to 60 min depending on meat thickness and fire intensity. As for tsire/suya (see be-low), the product receives no further stabilizing treatment. It is similar in moisture content(20% to 30%) and composition to tsire/suya, and its shelf life is also about 24 hr under am-bient conditions (18).

6. Indonesia Dendeng

Dendeng is a traditional Indonesian IM meat product containing coconut sugar, salt, andspices. It is prepared from meat in the form of thin slices (dendeng sayat) or from mincedmeat (dendeng giling). It may be prepared from beef, chicken, pork, or fish, but dried beef(dendeng sapi) is the major product found in the markets. Dendeng has a sweet taste due toits high sugar content, and together with strong flavor of the spices and the dried meat givesdendeng a characteristic flavor that differentiates it from other traditional IM meats, (e.g.,jerky, biltong). Fresh meat is sliced to about 3 mm thick and soaked for up to 12 hours atambient temperature in a mixture of coconut or palm sugar, salt, and spices (coriander,tamarind, garlic, and the root of the greater galangal, which can also contain onion, pepper,and other spices). The cured meat slices are put on trays to be sundried (dendeng sayat) ormechanically dried to aw of 0.52 to 0.67. For dendeng giling, the minced meat is mixed withground spices, coconut sugar, and salt, and then rolled into thin sheets 3 mm thick, and puton bamboo trays to be sun-dried. Typical dendeng giling has aw of 0.62 to 0.66. The ap-proximate composition of dendeng is pH 5.6, moisture 26%, protein 35%, fat 10%, salt 8%,and sugar 35% (dry wt. basis). Dendeng becomes tough and less elastic during storage for3 months at 50°C (18). Preservation of meat in Africa is conducted mainly by control of theinternal aqueous environment in relation to product quality and stability (19–22).

7. Malaysian Spiced Beef Slices (bak kua, rou pu)

In Malaysia, this product is usually made from pork. The product thickness is 2 to 3 mmwith a fairly high sugar content and it is sometimes known as dried sweet meat or barbe-cued dried meat. Traditionally this product is made only from pork, usually using ham orshoulder meat. The meat is partially frozen and sliced to the required thickness along themuscle grain using a meat slicer. The sliced meat is then soaked in a curing mixture madeup of salt, sugar, soy sauce, monosodium glutamate, spices, and permitted colors. After cur-ing for about 2 hr, the slices are placed on slightly oiled bamboo trays at 40° to 70°C forseveral hr until a moisture content of about 30% to 40% is reached. After drying, the slicesare stacked up and cut into squares. The product is then packed and kept in the chill room.For longer storage, a freezer is used. The product is usually sold in ready-to-eat form bygrilling partially dried slices over a charcoal fire until brownish in color. Maltose (�5%)

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can be added to give the product a wet and bright appearance. Rou pu has an aw of �0.69(3,20,21).

8. Chinese Style Dried Meat Slices (Chinese Rougan or Roupu)

Chinese rougan (Chinese slice-cured pork) has been described. The procedure utilizes pa-per-thin (0.2 cm) slices of lean meat cut parallel to the grain. The meat is cured with a mix-ture of sugar, salt, soy sauce, monosodium glutamate, and spices. The traditional cure doesnot use nitrite or nitrate. The meat is cured for 24 to 36 hours at 4°C and then the thin stripsare placed side by side (slightly overlapping) on an oiled bamboo basket or wire rack anddried at 50° to 60°C, until they lose approximately 50% of their original weight. The meatis removed from the containers and further dried by roasting over charcoal or deep fat friedto give a final aw of about 0.6 (3).

In another similar process, the whole muscle is boiled for 40 to 45 minutes, afterwhich it is cut into cubes or pieces (5 � 5 � 10 cm) (2,4).

Roupu is a product made very similarly to rougan except that more sugar is added tothe curing mixture to give the final product a sweet taste (2,4).

9. Chinese Shafu

Shafu is an improved rougan with a softer texture and lighter color; it is less sweet. The aw

of Shafu is about 0.79, and it is storable without refrigeration. Shafu is produced with ni-trite curing salt, sugar, and salt. The finished product is vacuum packaged (2,3).

C. Strips

Strip-type intermediate moisture meat or dried meat is produced by dry curing or picklecure. This step can be short (a few days) as the strips of meat are much thinner than the ham-type products. They are then sun-dried, smoked, or mechanically dried.

1. African Jirge

Jirge is the Hausa name for the sour sun-dried meat strips prepared and consumed byShuwa tribesman. It is a fermented, sun-dried meat prepared mostly from beef and occa-sionally mutton or goat meat. Jirge is like nkarki (see below) in all respects except that it isfermented prior to tearing into strips and drying. Meat for jirge is boned and cut into chunksthat are left until the meat starts to ferment to desired sour taste. It is then torn into stripsnot more than 2 cm thick and sun-dried with or without addition of salt and spices for sea-soning. Drying in the sun is by hanging strips over sticks, ropes, and galvanized/barb wireor by spreading over a mat. Drying takes about 5 days, depending on the weather, and themeat strips are turned daily to ensure uniform drying. Storage is as for ndakiko, in sacks,pots, and metal cans, and product shelf-life is up to 6 months or more (18).

2. Spanish (Dried Beef) Cecina

Spanish cecina resembles South American charqui (pronounced sharkey) and carne seca,and European Bundnerfleisch and bresaola. Spanish cecina is a salted, dried, and smokedbeef meat product manufactured almost exclusively in the province of Leon (northwestSpain). It has an aw of 0.86, posses excellent microbial stability, and can be stored withoutrefrigeration. The processing steps are as follows: Fresh beef pieces, make up of bicepsfemoris and semi-membraneous muscles, weighing 4 to 6 kg each, are covered with a mix-ture of coarse salt (ca. 0.15 kg per kg) and sodium nitrite (50 to 60 ppm) and held at 2° to



5°C and 75% to 95% R. H. for 72 hours. They are then washed to remove excess salt andheld under the same conditions for 30 days at 2° to 6°C and 80% to 90% R.H. This is thepost-salting or salt equalization stage. The meat is then placed in a smokehouse set at 12°to 15°C and is smoked for about 20 days. The smoking process is achieved by burning bothoak and beechwood inside the room. They are then dried for 40 days at 10° to 12°C and75% to 80% R. H. in a conditioning room. Finally, the meat is aged in a cellar for severalweeks (more than 60 days in a cold, dry environment) (23).

3. Mexican Cecina

The production method of Mexican cecina varies by location (24). It is generally preparedfrom lean hindquarters, cutting it into long slices 5�2 mm thick; the length can reach 1 mand width varies from 10 to 25 cm. Cutting is performed in the same direction as the mus-cle fiber. Addition of salt and other ingredients is not controlled. Experience determines theamounts to be added in each case. Cecinas so prepared stand unfolded on tables or are hungfrom 4 to 24 hours. Some cecinas are covered with a thin coat of safflower oil, and the ceci-nas are folded for distribution. Cecina is also allowed to stand for a time, followed by fold-ing and distribution. Vinegar is added after standing, and then moisture is reduced by a lightsun-drying process. The cecina is refrigerated and fat is added. Finally, it is also folded anddistributed.

4. African Biltong

Biltong can be made from the fillet steak (Binne biltong or ouma se biltong), eye muscle(garing biltong), or more commonly the hindquarter muscle of a young animal. In the man-ufacture of biltong, the selected muscles are dissected along their seams and cut into stripsresembling tongues (hence biltong) 25 to 30 cm long and 2 to 10 cm in diameter. A com-paratively lean well-fleshed “buttock” (i.e., hindquarter) will yield 70% biltong, 12% trimpieces, and 18% bone. During the drying process, 60% of the mass of the meat will be lost,so that a whole 6-kg cut of rump steak would yield only about 2.5 kg. Once the raw biltonghas been dissected and prepared, it is hung to dry suspended by strings or wire hooks. Indry weather or at a time of year when there are no flies, the strips may be hung in the sunon the first day. Thereafter, the biltong should be hung in the shade. Mildew may form un-less drying is rapid. If biltong is dried indoors, an electric fan may be used to keep the fliesaway. The period of drying and the stage of dryness at which the biltong is considered suit-able for further processing both appear to be flexible and a matter for the processor’s ownjudgement. The meat is salted either by immersion in brine or, more usually, by packing indry salt. The longer the biltong is left to salt, the more salt is absorbed. Biltong that con-tains a lot of fat takes longer to absorb salt than lean biltong. The biltong also becomes moresalty the longer it is left to dry out. As a result of these factors it is difficult to determine thequalities exactly since personal taste also plays an important role. One or other of variousspices such as aniseed, coriander, allspice, or garlic may be mixed with pepper and addedto the salt. Other optional ingredients are sugar, saltpeter (to promote a red color), andsodium bicarbonate (to counteract mold). Shin and Leitner (1983) found 25 biltong sam-ples had aw values ranging from 0.36 to 0.93, with most samples falling between 0.65 and0.85. The pH varied from 4.8 to 5.8, with most being around 5.5. Salt levels ranged from5% to 15%, with an average of 7%. The final product when packed away should be abso-lutely dry. Although the fat may become rancid, biltong will keep its qualities for manyyears if it is stored in a dry place. It may also be vacuum-packed in plastic film and placedin frozen storage where it will keep indefinitely (14,18,25).

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5. Pemmican (American Indian, especially the Cree)

Pemmican is the cold-environment equivalent of biltong. The original pemmican was in-vented by the American Indians, specifically the Cree. It is a dried meat product made frombuffalo, caribou, or deer, and later beef, which was packed in melted fat into specially maderawhide bags. The meat was dried in the sun and pounded or shredded prior to being mixedwith the melted fat. This preserving method is based on the air exclusion provided by thefat, which not only reduces oxidative changes but diminishes microbial growth. This is ac-complished not only by suppressing the growth of aerobic bacteria, but because the com-bination of a fat medium and dry conditions deprives the microorganisms of the water in-dispensable to metabolic functions. Mostly, the pemmican was flavored and partiallypreserved by the addition of dried, acid berries (26).

6. African Ndariko

Ndariko is a Fufulde (i.e., Fulani) and Hausa name for sun-dried meat with or without saltand spices. It is prepared mostly from beef and occasionally mutton and goat meat. Themeat is boned and the flesh torn into strips no more than 2 cm thick. The best products areobtained by tearing the muscle to pieces so that a group of muscle fibers can be dried as aunit. Salt, if applied, is only at a seasoning, rather than a preservative, level; so also is theuse of spices. The meat strips and cleaned intestines, with or without salt seasoning, arehung out in the sun on sticks, ropes, and galvanized/barb wire or spread on grass mats todry. Drying takes usually 6 to 7 days depending mainly on the weather and to some extentthe nature and size of meat strips. During drying the meat strips are turned daily, especiallyif spread on mats, to ensure uniform dehydration. The fully dried product is stored in sacks,pots or metal cans and has a shelf life of 3 to 6 months under ambient conditions (18).

7. Egyptian Basterma or Turkish Patirma

Basterma is one of the most popular cured and dried meat products in many Islamic coun-tries. It is produced mainly from beef and requires simple equipment and little energy forpreparation. Three steps are involved in the manufacture of Egyptian basterma: curing, dry-ing, and covering. The curing agents (common salts and potassium nitrate at 200 ppm) arerubbed dry over the surface of the beef (mainly Longissimus dorsi muscles) after incisionsare made on the meat surface. The meat is then layered to a thickness of up to one meter.The meat is left to stand for one day, after which more curing salts are added and the lay-ers are shifted. The meat is then left to stand for a second day, then removed from the cur-ing box and hung at room temperature for about 2 to 3 days. It is arranged in layers up to30 cm in length and put under one ton of pressure for 12 hr. The meat is then covered withpaste of 35% garlic, 20% fenugreek (Trsgnnella foenum graecum), 5% to 6% red paprikaand cumin, and 38% to 40% water. The dry meat is covered with paste (1 to 2 mm) andstored at 5°C for one day. It is stored at room temperature with good ventilation and soldafter ripening (nearly one month) (27,28).

8. Chinese-Style Bacon (La rou or smoke meat)

Chinese-style bacon is made from pork. It was usually made in the winter months when theweather is cold and dry. Nowadays, it can be made using refrigerated facilities and tem-perature-humidity controlled drying chambers. The cleaned meat with the skin on is cutinto long strips of about 0.6 kg each. Salt (6% to 12% of green weight of meat) and a smallamount of wild pepper (xanthoxylon seeds or fajou in Chinese) are stirr fried with low heat



to remove moisture, sanitize the seasoning ingredients, and develop the flavor of fajou.Three percent saltpeter is added and mixed well. This curing mix is set cooled and rubbedon the meat surface. The meat is then stacked in a container with layers of curing mix andpressed with a weight (stone) for 3 days. The position of meat strips is reversed and pressedagain for 3 days. The cured raw meat is hung in the sun to dry for 4 to 5 days, then held ina cool and ventilated place indoors. This cured meat is stable for over a year. The curedmeat can also be surface treated with soy sauce three times to improve the flavor. The curedmeat can also be smoked with oak and orange peels (2,4). The drying process can also beaccomplished by drying in electrical or gas-heated chambers. Vacuum packaging of theseproducts to preserve quality is also practiced nowadays.

D. Pieces

These products are usually in small pieces. The meat is cut into small pieces, precooked,and then smoke-dried or freeze-dried.

1. African Tsire (or Suya)

Suya is an Hausa word meaning roasted or fire-treated meat. It is in this sense a genericterm for partly or fully roasted meat products such as kilishi, tsire, and balanqu. Of these,however, the single product most commonly called suya in the trade is tsire, and the twonames are used synonymously. Tsire or suya is defined as boneless meat pieces (mostlybeef, but also mutton and goat meat) staked, smeared with a mixture of salt, spices,groundnut flour, and oils, roasted over around a low-burning or glowing smokeless fire.In the production of tsire or suya, meat is boned and cut into chunks about 10 cm longand 8 cm wide. The chunks are later sliced with a curved knife into slices about 1 cmthick. The meat slices are stacked on a slender wooden sticks about 30 cm long anddusted with a mixture of salt, spices, groundnut flour, and groundnut oil for seasoning.The meat stacks are then pinned, or incline on a wire mesh on top of an oven containinglow-burning or glowing firewood. Hardwood, low in resins, is used. Roasting takes placefor 20 to 40 minutes with occasional turning of the meat stakes. The product is displayedunpacked for sale and wrapped with paper for procurement. It receives no further treat-ment to enhance stability and its shelf life is only about 24 hours. Under ambient condi-tions, product moisture is about 20% to 25% (18).

2. African Banda

Banda consists of hard-smoked pieces of meat mostly from reject cattle, discarded trans-port beast such as donkeys, horses, asses, camels, buffalo, and elephants as well as wildlife.Banda is the most commonly produced traditional African dried meat. The animal, afterslaughter, is eviscerated and butchered and the large bones are removed. Virtually all of thecarcass, including the lean meat, organs, neckbones, ribs, and legs as well as hides/skinsand intestines, are used up. These are cut into pieces about 3 to 6 cm and cooked with asmall amount of water in half-drums for 15 to 30 min with intermittent stirring. When done,the meat pieces are shovelled out and spread on the floor or mat or on wire mesh over thesmoking pit or oven to drain-dry. The meat pieces are then smoked with fire generated fromburning hardwood in the smoking pit or earthen oven directly below the meat pieces. Thisinvolves high-temperature (hot) smoking leading to further cooking, drying, and shrinkage.Smoking lasts for 18 to 30 hours, depending on meat size and fire intensity, during whichtime the meat pieces are turned periodically to ensure uniform smoke-drying. A mat is used

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to cover the meat pieces to trap the smoke while the fire intensity is controlled by regulat-ing the quantity of burning wood so as to prevent meat charring. At the end of smoking, thefire is quenched and the meat pieces allowed to cool down to ambient temperature beforestorage or packaging in sacks and jute/mat bags. The product is dark in color with a stone-dry texture and 5% to 16% moisture. It is a very stable product with a shelf life of 6 to 12months or even up to 2 years under ambient temperature (18).

3. Freeze-dried Meat Pieces

With the popularity of instant noodles and instant soup mixes, the demand for freeze-driedmeat pieces has increased considerably in recent years. These products are usually pro-duced by cutting or grinding the raw meat into small pieces, precooking the meat pieces,freezing the cooked meat, and finally freeze-drying to very low moisture content (29,30).

E. Floss or Shreds

Meat floss or shreds are unique Chinese products. They are usually produced by cookingthe meat to tender followed by shredding the meat into bundles of meat fibers before cook-ing in the seasoning liquid to a dried product. However, the final water activity may varydepending on the kinds of product. The texture can be a little bit chewy to very crispy.

1. Meat Floss (rou song)

The method of producing meat floss is quite similar to that of shredded beef (see below).Lean pork or chicken meat is cut along the fiber and cooked in water until it is very soft.The broth is then drained from the meat and kept for later use. The meat is mashed manu-ally into fibrous strips. While the broth is concentrated, the shredded meat is added. Themeat mass is then heated at low heat and continuously stirred manually until the desireddryness is achieved. At the final stages of drying, the temperature can be raised to speed upthe drying process. The aw of beef floss is 0.60–0.62 (31,32).

2. Taiwanese Zousoon (pork floss)

Zousoon is a semi-dry pork product that has a aw of 0.60 to 0.65. In preparation, the pre-rigor muscle is cut into pieces parallel to the direction of the muscle fibers to allow heatpenetration and yet still maintain the integrity of the long muscle fibers (33). The raw pre-rigor muscle is boiled in water in a large shallow gas-fired kettle for about 80 minutes tosolubilize the collagenous fibers and to evaporate some of the moisture until the leached-out solids are reabsorbed by the muscle. The heated muscle is then manually pressed witha paddle to loosen the fibers from the large muscle bundles, in order to facilitate drying andto yield the long fibers. The partially disintegrated bundles of fibers are transferred to a gas-fired frypan equipped with a continuous mechanical scraper to aid in concomitant dryingand disintegration of the muscle bundles into long fibers. Sucrose and salt are added to themuscle at a ratio of raw lean meat:sucrose:salt of 1000:100:15 while heating. Addition ofthe sucrose and salt too early during heating decreases the efficiency of moisture removal.Dehydrated starch cells are added at a ratio of 0 to 40 of the original raw meat at a mois-ture level of about 42%. This lowers the average moisture content of the mixture while oc-cupying the void space and aiding in maintaining a loosened texture. Once the desired con-sistency and water activity are achieved, the predried mixture can be stored at eitherambient or cooler temperature until it is removed and finished. The finished product is pre-pared by adding the predried fibers back to the scraping-frypan and heating. Hot melted



lard (at a ratio of 20 to 120) is added and the material is heated until the long fibers reachaw of 0.60 to 0.65. The finished product has a sweet-meaty flavor, a chewy texture, and alight brown color. There are commercially available two types of meat floss, which differin texture. Although both have cotton-like appearance, one is more crispy. This is made byadding some vegetable oil to the normal product and a short drying period at a lower tem-perature is given to achieve the crispy texture. In general, ingredients used are soy sauce,five spice powder, pepper, sugar, and monosodium glutamate (33). If the rate of heating ordrying is too fast or the temperature gets too high, the fibers collapse and become short(about 1 to 2 cm) and have a darker color and poorer flavor. In this case, it is referred to asthe ‘short-fibered’ or the ‘dry roasted’ product, and has aw of 0.40 or below.

3. Malaysian Sambal Daging (shredded spiced beef)

In the production of sambal daging, coarse fiber meat such as rump is normally used. Themeat is cut into pieces of about 5 � 5 � 10 cm. The pieces are then boiled in water untilthey are quite tender, then are drained and allowed to cool. When sufficiently cooled, thefibers of cooked meat are pulled apart manually to obtain strands of meat. While the meatis being shredded, the sauce is prepared. The broth obtained earlier is used in the blendingof the ingredients, which include coconut milk, sugar, onion, garlic, ginger, salt, tamarind,dried chili, and coriander. The type and amounts of ingredients used may vary from man-ufacturer to manufacturer depending on consumer taste preferences. All the ingredients arepoured into an oval-shaped saucepan and heat-concentrated with constant stirring to pre-vent charring. When concentrated to about 50% of its original volume, the shredded meatis poured into the saucepan and stirred continuously until the desired dryness of the prod-uct is achieved. Usually toward the later part of cooking, the intensity of the heat is low-ered to prevent charring of the product. The manufacturing process could take up to 5hours, a greater part of this period requiring continuous stirring. The aw is 0.48 to 0.61 (20).

F. Powder

Meat powder such as Sudanese sharmoot is another unique product made by first dryingthe meat strips in the sun or in drying chambers. The dried meat is then ground to a pow-der form for storage and usage.

Sudanese Sharmoot. Sudanese Sharmoot is a powdered dried meat product preparedtraditionally by cutting the meat into thin strips, hanging it in the sun for 3 to 5 days untilit is dry, then grinding it into a fine powder. An improved procedure is to grind the meat,precook it, and then dry at 65.5°C with forced air for 3 hours before grinding into powder(34).

G. Sausages

Sausages are usually produced by grinding or cutting the meat, followed by mixing it withcuring and seasoning agents. The mixture is then stuffed into natural or artificial casings.The size of the sausage may vary depending on the origin and culture. The raw sausage isthen subject to drying, smoking, or both. Some products are dried to the desirable water ac-tivity in a short time, and some are dried slowly with a mild fermentation. Intermediate-moisture sausages can be classified by particle size or degree of chopping into three cate-gories: emulsion-type, coarse ground, and muscle cube.

Most of the sausages processed in Mid-East, European, and American countries be-long to the category of emulsion-type products. Usually the lean meat is first comminuted

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in the presence of salt to extract the highest concentration of myofibrillar proteins (actin,myosin, and actomyosin) to stabilize the batter. As the fat component is added and minced,the fat particles are encapsulated by the extracted protein. The extracted proteins facilitatesurrounding and interacting with the fat particles or droplets with their emulsification ca-pability. A sausage batter is actually a very complex mixture consisting of suspended par-ticles (collagen fibers, myofibrils, cellular organelles), immobilized and free water, lipiddroplets and particles, and hydrated, solubilized, and nonsolubilized myofibrillar proteins.

1. Lebanon Bologna

Lebanon bologna is a semidry type, coarse-ground, fermented product requiring knowl-edge of the art. It can be prepared using starter cultures, or it can be held under specific con-ditions that preferentially promote the growth of organisms that impart flavor, texture, andpreservative qualities. Whole-carcass cow meat is salted with 2% salt and held for 8 to 10days at 34° to 38°F. The beef is ground through a 1/2 inch plate and mixed in a ribbon mixerwith the salt, sugar, spices, and sodium nitrate. The mixture is then passed through an 1/8inch plate and stuffed into No. 8 fibrous casings. The filled casings are tied and stockinet-ted for support. The product is transferred to a smokehouse for a 4- to 7-day cold smoke,usually 4 days in the summer months and 7 days in the late fall and winter months. Lebanonbologna is traditionally made under conditions that call for little or no refrigeration. Thefinished product is extremely stable, even though the moisture content may be as high as55% to 58%. The salt content of the finished product is usually 4.5% to 5.0% and the pHranges from 4.7 to 5.0 (32).

2. Dry Sausages (beef and pork Genoa, hard salami, pepperoni)

The manufacture of dry sausages is steeped in art. However, the art is slowly yielding tothe advance of science. Usually the meat is ground and mixed with the curing mix consist-ing of salt sugar, spices, and nitrate. Sometimes wine is also added as in Genoa. The mix-ture is briefly mixed until a good distribution of the fat and lean is apparent. The mixture isthen stuffed into casings. The stuffed product is held under controlled temperature and hu-midity conditions until the desirable degrees of desiccation and fermentation are reached.Hot smoking may also be applied. Safety of these products are usually accomplished byovercoming the hurdles in the manufacturing processes (5).

3. Spanish Salchichon

Salchichon is a popular Spanish-style sausage; the Spanish name means large sausage. Itcan be made from lean beef, lean pork, or a combination of both. Pork backfat is addedalong with seasoning (1% to 4% salt, nitrate, and white pepper) and sugar 1% of a 1:1mixture of sucrose and dextrose). It is normally held at a temperature of 25° to 30°C anda R. H. of 80% to 90% for 5 days, after which it is held for an additional 60 days at 30°to 37°C and 70% to 80% R. H. for maturation. This reduces the moisture content fromabout 50% to 60% to 26% to 35%. The final aw is 0.80 to 0.87, and the final pH is 4.6to 4.8 (36).

The production and physicochemical characteristics of salchichon, which was madefrom lean ground cow 40% beef, 30% lean pork and 30% pork fat. It contains about 3%salt, 1% sucrose, 1% dextrose, 0.5% wine, 0.25% ground pepper, whole pepper, potassiumnitrate, and sodium nitrite, which were ground and mixed together. Incubated at 20°C and80% R. H. for 5 days after stuffing in large casings (natural or artificial), salchichon thenundergoes maturation at about 12°C at 70% R. H. for an additional 60 days. Salchichon



made this way has a final composition of about 25% protein, 27% moisture and 43% fat,and 5% ash. It has a final pH 5.90 and aw 0.85 (37).

4. Cervelet

Cervelet is a dried, smoked, cooked sausage. An improved processing procedure includeshot meat freeze-dried with curing salt and starter culture, rehydrated in cutter to 100% with80% ice chips � 20% water, frozen to �42°C in a plate freezer, comminuted in a frozen-meat-mincer, added to the cutter before the other ingredients and processed in the usualway (37,38).

5. Chinese Sausage (Lup Cheong)

Several grades of Chinese sausages are available commercially. The quality of grade de-pends on the meat to fat ratio. For liver sausage, the meat is replaced by liver. Pork is usu-ally used for the manufacture of Chinese sausage, although chicken or turkey meat can alsobe used. The meat used in the manufacture of Chinese sausage is usually ham meat and thefat is from backfat. The meat is manually cut into short strips and the fat is cut into 10 mmcubes. The meat and fat are then mixed thoroughly with the seasoning mixture and are leftto marinate for several hours before filling is carried out. The casing used for Chinesesausage is usually derived from the small intestines of the pig. This type of casing is usu-ally in the dry form and must be soaked in water before use. With the help of a funnel, themixture of meat and fat is forced into the casing, which is tied at one end. The casing ispunctured with needles to allow air trapped during the filling process to escape. After be-ing knotted into short sections and given a water spray to remove any adhering ingredients,the sausage is allowed to drip for a while before it is dried in a drying cabinet. The heatsource is usually burning charcoal. This drying process can continue for up to 3 days, de-pending on the temperature used. The aw of lup cheong is 0.75 (2,4).

Instead of slicing and cutting the meat, it can be minced through an 8 mm plat. Frozenslabs of backfat that have previously been mixed with salt to remove some water are passedthrough the machine again with the strips fed across the series of parallel rotating blades toobtain cubes. The minced meat and fat are then mixed thoroughly in the seasoning mixturebefore filling into the casing. The filling process is carried out using an automatic filler withautomatic linking facility that can control the weight of each sausage. Pig intestine casingis also replaced by collagen casing. The amount of heat applied can also be regulated moreprecisely by modern convection type temperature-controlled drying cabinets equipped withcondensers to reduce the drying time from 72 hour to 35 to 48 hour (2,4).

One suggested seasoning mixture consists of ascorbic acid, Chinese wine, light soysauce, antioxidant, water, and curing mixture (0.25% sodium nitrite, 0.5% sodium nitrateand 99% salt) (2,4).

II. STABILITY OF INTERMEDIATE-MOISTURE MEATS

Microbial issues, enzymatic deterioration, chemical deterioration, nutritional and sensorystability, and packaging issues will be discussed in this section.

A. Microbial Stability and Safety

Although fresh meat is an ideal medium for bacterial growth and subject to rapid spoilage,the interior of the animal is virtually free of organisms except for the lymph nodes and ex-cluding the gastrointestinal and respiratory tracts (39). Environmental conditions prior to

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slaughter and during processing affect the degree of contamination of the surfaces of meat.Microbial spoilage of meat generally may be attributed to the activity of the surface mi-croflora. Deep muscle penetration and growth are not significant (40,41). A different groupof microflora is found on cured, processed meats as compared to those in fresh meats. Bac-teria such as Staphylococcus, Micrococcus, Pediococcus, Streptococcus, Lactobacillus,Clostridium, and Bacillus have been isolated from cured meat. Yeasts and molds are notusually associated with freshly made cured meats, but after aging, sausages and country-cured hams may show growth of these fungi. In general, yeasts and especially molds arethe major spoilage factors of traditional intermediate-moisture meat products.

Recent outbreaks of foodborne illness due to Salmonella spp. in beef jerky and Es-cherichia coli O157:H7 in venison jerky raise great concern over the safety of intermedi-ate-moisture meat products made in the home. The potential of injured bacterial cells to re-gain the ability to cause illness is a particular threat with pathogens such as E. coliO157:H7, which is believed to have a low infectious dose (42). Micrococci and strepto-cocci, which predominate on cured meat, resist salt and nitrite but are affected by pH in thepractical range.

1. Minimum Water Activity for Microorganisms

The aw of food influences the multiplication and metabolic activity (including toxin pro-duction) of microorganisms, also their survival and resistance. In the aw range of IMM(0.60 to 0.90) some bacteria (Pediococcus, Streptococcus, Micrococcus, Lactobacillus,Vibrio, Staphylococcus), yeast (Hansenula, Candida, Hanseniaspora, Torulopsis, Debary-omyces, Saccharomyces) and molds (Cladosporium, Paecilomyces, Penicillium, As-pergillus, Emericella, Eremascus, Wallemia, Eurotium, Chrysosporium, Monascus) maymultiply. Most of these organisms cause spoilage; some produce toxins (Staphylococcus,Paecilomyces, Penicillium, Aspergillus, Emericella, Eurotium). Yersinia enterocolitia hasbeen isolated from meat foods and has become of increasing concern as a cause of gas-troenteritis and other syndromes in humans (43).

The aw requirements of some microorganisms have been reported by different au-thors. The generally accepted minimum aw for some important meat pathogen are listed inTable 2. Among them, Staphylococcus aureusi is the lowest aw tolerating bacteria, whichunder anaerobic conditions is inhibited at an aw lower than 0.90 but aerobically at an aw

�0.86. It was noted that the mean growth rates of Staphylococcus aureusi are higher at anaw level of 0.995 and 0.990 than at 0.999. Below these optimal aw levels, growth rates de-crease as a function of aw. Slow growth was observed at 0.86 aw, with total growth sup-pression at 0.84 aw (44,45).


Table 2 Minimal aw for Multiplication of Major MicroorganismsPresent in IMM

Bacteria IMM Minimum aw

Clostridium Pork sausage 0.97Salmonella Beef jerky 0.95Escherichia coli Venison jerky 0.95Bacillus Sharmoot 0.95Microbacterium Cecina 0.94Staphylococci Basterma 0.86


Of the gram-negative rods, Salmonella and Escherichia coli are the representatives.The growth and toxin production of Clostridium botulilum type C is inhibited below an aw

of 0.98 (46) of Clostridium botulilum type E � 0.97 (47), and Clostridium botulilum typeA and B (48), and Cl. Perfringens �0.95 (49).

2. Microflora in Traditional Intermediate-Moisture Meat Products

Obviously, environmental factors such as temperature of processing, curing salts, sugarsand other ingredients, smoking, and storage conditions all affect the microflora that devel-ops on IM meats.

Microbiological quality of 125 samples of the most popular Egyptian meat products[(75 samples of Egyptian fresh sausage (EFS) and 50 samples of basterma] was determined(27). The aerobic plate count (APC) and Lactobacillaceae count of basterma ranged from1 � 104 to 9 � 106 cfu/g, respectively. Enterobacteriaceae, fungal, and yeast counts forbasterma were similar (�1 � 102 cfu/g). Twenty samples each of (a) minced meat, (b) lun-cheon meat, and (c) basterma (a dried meat product) were obtained from the Assiut Citymarket and analyzed mycologically (50). The genera and number of species identified wereDebaryomyces, 5 species; Candida, 7 species; Saccharomyces, 3 species; Torulopsis, 3species; Rhodotorula, 2 species; Trichosporon, 1 species. Predominant mold genera werePenicillium and Aspergillus; predominant yeast genera were Debaryomyces and Tri-chosporon, which in addition to Debaryomyces frequently contained Candida andRhodotorula (50).

Twenty one samples of cecina was examined microbiologically, both on their sur-faces and internally, for salt-tolerant microflora, Micrococcaceae, lactic acid bacteria, andyeasts (23). Throughout curing, the dominant flora on the product (both internally and ex-ternally) were micrococci; surface microccoci were present at a level of 107 cfu/g, whereaslevels in the deep tissue of the product were approximately 103 to 104 cfu/g. Levels ofyeasts and lactic acid bacteria were also high in both locations. Of 159 isolates belongingto the family Micrococcaceae, 81% were Staphylococcus (with S. equorum, S. xylosus, S.saprophyticus and S. simulans being the most abundant species). The remainder were Mi-crococcus spp. (11%) or were unknown (8%).

In finished biltong, which is an unheated meat product, total counts of �107/g and106/g molds and yeasts respectively have been reported (51). The dominant component ofthe microflora of the final products is gram-positive, halotolerant staphylococci (coagulase-negative) and micrococci (51). Stable biltong had a total count of 103 to 106/g, and con-tained lactobacilli and Micrococaeae in relatively high numbers (52).

Twenty genera of molds were isolated from different kinds of meats products in-cluding bacon, hams (particularly country-cured hams), salami, and dry sausages. Amongthe molds isolated, Aspergillus and Penicillium species predominate (53). It was concludedthat fungi are important in retention of moisture and color of aged hams and sausages. Peni-cillia and aspergilli grow on hams after the most loss about 25% to 30% of the originalweight as moisture, and the aw become reduced (54).

A total of 670 strains of fungi were isolated in the cured and aged meats (fermentedsausages, country-cured hams, and country-cured bacon) that were collected from theUnited States and Europe (55). These strains included 456 molds and 214 yeast, whichwere considered to be typical of the microflora from the products. Yeast was more com-monly associated with fermented sausages than with country-cured hams, and were foundmainly on the surface of products; they contributed to spoilage when present in highnumbers.

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From the 42 stable imported commercial Chinese IMMs from Taiwan (20 samples),Singapore (18 samples), and Hong Kong (4 samples), rarely was recovered more than 104

microorganisms/g, and most samples were in the range 102 to 103 g. This microbial stabil-ity was contributed to the hurdles of water activity and heat treatment, with little contribu-tion from the pH hurdle. It was concluded that Chinese IMMs are microbiologically safeproducts because the heat treatment eliminates most organisms present in the raw material.Further, the survivors and microorganisms that recontaminate the product are inhibited andinactivated by the critical aw of 0.69 (56).

3. Pathogens in Traditional Intermediate-Moisture Meat Products

It was reported that commercial pork sausage had an incidence of C. perfringens of ap-proximately 39% (57). In a survey of retail stores, the possible causes of outbreaks ofstaphylococcal intoxication following consumption of any fermented sausage such asGenoa salami was reviewed. Microorganisms, particularly staphylococci, may grow inproducts that are not smoked or cooked and are held at temperature �18°C before drying(58). Botulism is a rare food toxemia caused by anaerobic, spore-forming bacillus. Mostbotulism outbreaks are caused by home-preserved foods. Nitrite and salts as well as refrig-eration play important roles in controlling botulism in cured meat; inadequate thermal pro-cessing was a contributory factor in some instance (59).

The safety of basturma, an intermediate-moisture meat product, from salmonella wasinvestigated and it was found that the product is generally safe (60). The identification ofstaphylococci and micrococci isolated from basturma was studied. Of the 120 isolates,92.5% were classified as staphylococci and 7.5% as micrococci. Differentiation of thespecies revealed 42% Staphylococcus epidermidis, 32% Staphylococcus saprophyticus,12% Staphylococcus simulans, 4% Staphylococcus carnosus, 2% Staphylococcus hyicussubsp. hyicus and 7.5% Micrococcus varians (61). Microbial stability and potential for sur-vival and growth of certain food poisoning microorganisms in basturma were evaluated(61) by inoculating the freshly pasted product with two common pathogens, Staphylococ-cus aureus and S. abortusovis, and following their counts during storage. Both pathogenssurvived the final dehydration stage but their counts remained fairly steady during 60 daysof refrigerated storage. Enterobacteriaceae, salmonellae, S. aureus, yeasts and molds werenot detected in commercial samples (62). The survival of salmonellae, anthrax bacilli, andpathogenic clostridia in pastirma was investigated and this product was found virtually freeof these organisms (63).

Staphylococcs aureus and its enterotoxins are not of much concerns in biltong withlow aw (52). However, the recovery of Salmonella spp. from biltong has been reported byVan den Heever (65). Salmonellae survive for a long time in biltong, especially in the prod-uct made from the muscle of diseased animals. Biltong with such endogenous infection hascaused salmonellosis in humans (66). Care in the selection of meat as well as good hygienein the processing of biltong must be emphasized.

Dry sausages have often been implicated in outbreaks of staphylococcal food poi-soning and are frequently contaminated by Salmonella and coliforms (67). Both groups ofmicroorganism are widely distributed in meats and may grow during the first part of the fer-mentation process.

4. Artificial Inoculation Tests in Traditional Intermediate-Moisture MeatProducts

Artificially contaminated slices of basterma plus garlic paste showed that the paste inhib-ited growth of Salmonella typhimurium (27). APC and Enterobacteriaceae counts of EFS



(Egyptian fresh sausage) ranged from 1.1 � 104 to 1 � 108 and from 1 � 102 to 1 � 107

cfu/g, respectively. Nearly 26% and 29% of EFS were positive for Clostridium perfringensand coagulase-positive Staphylococcus aureus, respectively. Salmonella was not detectedin any samples. The fate of pathogens inoculated onto ready-to-eat cured meats has beenexamined (68,69). The data show that Clostridium perfringins was incapable of growingon sliced ham, chopped ham or bologna at abusive holding temperature.

Intermediate moisture meat products were collected in Taiwan, Hong Kong, and Sin-gapore, and evaluated (64) for physicochemical and microbial composition, as affectingstability. The reproduced Chinese IMM showed that salmonellae, pathogenic staphylo-cocci, yeasts, and molds are eliminated during the usual processing by heat applied. Ente-rococci may survive the process, but die during storage of the product. Spores of bacilli andclostridia decrease during processing and storage too but do not disappear completely (64).Three different procedures used in China for preparation of dried meats, as well as that forpreparation of Chinese sausage, were studied (4). They had on receipt water activities in therange of 0.785 to 0.200, and pH values of 6.21 to 5.27. Thirty-five of the products provedmicrobiologically stable after inoculation with xerotolerant molds of the Aspergillus glau-cus group and storage for 3 months at 25°C. These stable products contained 15% to 35%sucrose, 3% to 5% NaCl, and 10% to 20% moisture; some, more drastically treated, had 2%to 12% moisture. The sausage produced in the laboratory using traditional recipes con-tained 10% sucrose and 2% NaCl; Salmonellae did not multiply in it, but Staphylococcusaureus did, hence heating before consumption was necessary.

Whole dry-cured (country-style) hams from six manufacturers were sliced and inoc-ulated with approximately 105 cfu/g of ham of Escherichia coli O157:H7, Listeria mono-cytogenes, a mixture of three Salmonella spp. (Salmonella typhimurium, Salmonella enter-itidis, and Salmonella choleraesuis), or Staphylococcus aureus. All ham slices werevacuum-packaged and stored at 25°C or 2°C. S. aureus was detected in 2 of 60 controlslices, Salmonella in 2 of 120, L. monocytogenes in 4 of 120, and E. coli O157:H7 was notdetected in any of the 120 control ham slices analyzed before or after storage. The extentof the decreases in populations of the inoculated pathogens during storage of vacuum-pack-aged dry-cured ham slices. Decreases in Salmonella spp. and E. coli O157:H7 populationswere greater in slices stored at 25°C than at 2°C, whereas decreases in L. monocytogeneswere similar at both storage temperatures. Staphylococcus aureus enterotoxin was not de-tected in either S. aureus–inoculated or control ham slices after storage for 28 days. Sur-vival of these pathogens in vacuum-packaged dry-cured ham slices suggests that contami-nated hams may pose a safety risk to consumers if eaten without adequate cooking (70).

A total of 420 samples of smoke-dried meats (smoked meat products, ham, porksausage, bacon) was collected over 3 years from different regions of Croatia and analyzedfor the presence of aflatoxigenic strains of Aspergillus. Strains of A. flavus (69 samples) andA. parasiticus (6 samples) were found in 17.8% of samples. Eight of these 75 strains pro-duced aflatoxins. A. flavus strains produced mainly aflatoxin B1 (1.4 to 3.12 mg/kg). Somestrains of A. parasiticus produced aflatoxins B1, B2, G1, and G2; others produced aflatox-ins B1 and G1 only, at concentration of 0.1 to 450 mg/kg (68). Aflatoxins are unlikely tobe encountered in biltong with aw �0.80, even though A. flavus quite frequently occurs onthe product (25). Similar results were reported by other researchers (72): They stated thatalthough Aspergillus flavus is frequently isolated from biltong, aflatoxins are not normallyfound in biltong.

The decrease of aw during charqui processing promoted a gradual inhibition of mi-crobial contamination (10). Investigators claimed that it is possible to produce charqui with

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low counts of microorganisms when adequate hygienic conditions are maintained duringprocessing and storage. The high level of contamination observed in charqui sample pur-chased from a retail market were a consequence of mishandling the products.

The Sudanese dried meat, Sharmoot is a major food product in East Africa (73). Theproduct was chemically and microbiologically stable for at least 4 months without refrig-eration. Although staphylococci and Enterobacteriaceae were the most common major bac-terial groups isolated from dried meat samples at the beginning, micrococci and bacilli pre-dominated during the last stages of storage. Microbiological data (total, spore, yeast, andmold; Staphylococcus aureus counts; and Clostridium perfringens detection) indicated thatthe product was microbiologically more acceptable than the comparable product made tra-ditionally in the Sudan. The potential exists for large-scale production of Sharmoot.

An inoculation study was conducted to determine the efficiency of glycerol in re-ducing known bacterial loads in intermediate moisture pork products (74). Cooked samplesof pork tenderloin were equilibrated in glycerol solutions at both high (55°C) and low (5°C)temperatures and the preservative effect of intermediate-moisture conditions in meat wasinvestigated. A mixed spoilage culture containing aerobes, pseudomonads, and coagulase-positive staphylococci was obtained from a pork sample kept at 5°C for 5 days. The resultsindicated that the glycerol infusion equilibrium process appeared to be successful in preser-vation of meat stored at both room temperature and refrigeration temperature for a periodof 3 weeks. This finding is in good agreement with that published by others (75). These IMsystems studied were microbiologically stable for up to 6 months storage (76). In summary,intermediate-moisture beef, pork and chicken products have been extensively examined,and processing methods included salting, drying, smoking, immersing in oil, and casing.The survival ability of various organisms on meat is at low aw (approx. 0.6) and, generally,bacilli and streptococci survived best and yeast worst.

B. Chemical Stability

Although intermediate-moisture products are microbially more stable than raw or cookedmeat, they are still subject to deterioration through chemical and physical processes in-cluding oxidation, protein denaturation, cross-linkage and browning, which can reducetheir nutritive value and eating quality (77).

Dry sausages made with a normal recipe have a fat content of around 40% to 50%(78). Pork back fat used in fermented sausages has above 60% unsaturated fatty acid. Thelarge majority of IMMs are stored in air-permeable packaging material. This permits theoxidation of unsaturated fatty acid, especially those in the finely comminuted meat prod-ucts (79). A close relationship between moisture, protein, and ash values was found (10),suggesting the possibility of using the resulting charqui aw value as a parameter to definethe product instead of the official moisture and mineral residue contents. TBA determina-tion, which expresses the state of lipid oxidation, rapidly reached a maximum value, corre-sponding to previous observations on the pro-oxidant role of salt, and then decreasedgradually.

Kilishi stored for 60 wk under ambient conditions in cellophane bags was analyzedfor lipid and fatty acid profiles and oxidative stability. Total lipid content was 25%, of which89.42% was triglyceride (TG) and 10.57% phospholipid (PL). TBA number had reached2.01 in 60 weeks (in mg malonaldehyde/1000 g meat). The major TBA-reactive substancein kilishi distillates was not malonaldehyde, as in beef or chicken, but an unidentified alde-hydic browning product with a spectrophotometric peak at about 440 nm (17). It was re-



ported that TBA numbers of dendeng decrease during the early stages of storage but increaseduring prolonged storage (e.g., �6 months at 37°C) (19). The oxidation of lipid and choles-terol in Chinese-style sausage stored for 5 months was investigated (80). The 2-thiobarbi-taric acid active substance and peroxide value of sausage stored at 15°C were significantlygreater than at 4°C. The polyunsaturated fatty acids in sausage decreased with storage, andthe content of cholesterol decreased significantly after 3 months of storage. 7-Beta-hydrox-ycholesterol, 7-keto cholesterol, and 22-keto cholesterol were the major cholesterol oxida-tion products, but there was no detectable 25-hydroxycholesterol or cholesterol.

Biochemical changes in cecina-like meat were evaluated during storage (81). Sam-ples of cecina from different states of Mexico were tested for aw, color, texture, fat, protein,moisture, and chloride content. Based on the low activation energy for hematin complexdegradation (around 1 Kcal/mol), the manufacturing of cecina is regarded as a low-energybiochemical process.

Chemical analyses of kundi (normally beef-based) showed that, apart from a highlevel of carcinogenic benzo(a)pyrene (10.5 to 66.9 ng/g), eight other polycyclic aromatichydrocarbons (PAH were present at various concentrations (82). The high levels of PAHin kundi were due to the high glow and smoking temperature, averaging 926°C and191.5°C, respectively. Column chromatography was used for PAH extraction, with propy-lene carbonate as the eluting chemical; TLC on acetylated cellulose layer plates was usedfor separation, and the determination was performed using spectrophotofluorimetry. Thepublic health implications of PAH as one of the possible carcinogenic factors in the highincidence of primary liver and stomach cancer reported in Nigeria are highlighted.

III. STRUCTURAL COMPONENTS OF MUSCLE TISSUERESPONSIBLE FOR PHYSICOCHEMICAL PROPERTIES OFINTERMEDIATE-MOISTURE MEAT PRODUCTS

In order to fully understand the structural components of muscle and their involvement inthe production of IMM, the gross structure of muscle will be described first, followed by adescription of some of the ultrastructural elements involved.

A. Gross Meat Structure

The bodies of meat-producing animals are composed of about 300 anatomically distinctstructural units that differ greatly in size, shape, and appearance (83). Muscle tissue con-tains numerous structural components; among them connective tissue, myofibrillar pro-teins, muscle membrane, and water are significant contributors to the physical properties ofintermediate moisture meat products (84). The intact muscle is composed of numerousfibers that generally parallel the long axis of the muscle. These fibers, representing musclecells, are between 50 and 100 �m in diameter and vary in length from a few millimeters upto several centimeters. Muscle fibers are described as cylindrical. The fibers themselvescontain about one thousand myofibrils about 1 to 2 �m in diameter that run through thewhole length of the muscle fiber. The myofibrils consist of alternating thick and thin fila-ments. The segment between two consecutive Z-lines is called the sarcomere (85).

1. Muscle Membrane and Connective Tissue

The lipoprotein nature of cell membrane precludes a primary function for this material inthe physical properties of muscle. The entire surface of the muscle fiber is covered by a unit

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membrane called the plasmalemma (86). Another membrane system, the sarcoplasmicreticulum (SR) is found in the sarcoplasm that separates myofibrils. Endomysium has atleast three roles: (a) muscle fiber-muscle-fiber connections (b) muscle-fiber-capillary con-nection, and (c) a weave network of collagen intimately associated with the basal laminaeof the muscle fibers (87). The plasma membrane of the muscle fiber has several functions:(a) it forms a selective barrier that regulates transport of ions and molecules in and out ofthe cell, (b) it has the ability to transmit an action potential generated by a nerve, and (c) itis involved in the transmission of force produced by the contractile apparatus within themuscle cell (88).

On the examination of muscle tissue that is used widely in the traditional IM meatproducts in cross-section (as shown in Figs. 1 and 2), there is a fairly thick envelope of con-nective tissue surrounding each individual muscle. This thick layer of connective tissuearound an entire muscle is known as the epimysium, whereas the smaller layer of connec-tive tissue dividing the muscle into bundles or fasciculi is called the perimysium. A stillfiner connective tissue layer extends from the perimysium into the muscle fiber bundles andencircles each muscle fiber. This thin layer of connective tissue consists of reticular fibercarrying the blood capillaries and is called the endomysium. The epimysium is generallyeasily separated from the body of the muscle, whereas perimysium and endomysium arenot practically separated from meat (89).


Figure 1 Schematic diagram of disintegration of muscle tissue into muscle fibers during the prepa-ration of an intermediate moisture meat product such as Zousoon.


The connective tissue layer is composed of two proteins, collagen and elastin. Bothof these proteins have their own characteristic amino acid composition. Collagen is themore abundant of these two proteins, representing about 2% to 6% or more of the dryweight of muscle. Collagen is usually found in the fascia surrounding the epimysium, per-imysium, and endomysium (90).

At least 15 genetically distinct types of collagen have been characterized (91).The major type of collagen present in muscle have been characterized. Among them,intramuscular collagen deserves special interest. These collagen are located in the

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A

B

C

Figure 2 Disintegration of intact pork muscle fiber bundles (A) into separated bundles (B) andthen single pork muscle fiber (C) during preparation steps in the production of Zousoon.


endomysial basement membranes by immunofluorescent staining. A specific distributionof genetically distinct forms of collagen within epi-, peri-, and endomysial connectivetissues was demonstrated by the presence of type I collagen in the epimysium, type Iand III in the perimysium, and type III, IV, and V in the endomysium from bovinmuscle (92).

2. Myofibrillar Proteins

Among the 200 distinguishable protein complements, only a few appear to be directly in-volved in dictating the physical properties of intermediate-moisture meat products (93).

3. Contractile Proteins

The muscle myofibril has been found to be composed of a number of distinct elements. Thethick filament consists mainly of myosin (55% of the myofibrillar proteins) and C protein(2%). The components of the thin filament are actin (23%), tropomyosin (6%), and tro-ponin (6%). Other myofibrillar proteins are present in lower concentrations (94). As a con-sequence of postmortem depletion of adenosine triphosphate (ATP), actin (located in the Iband and the major constituent of the thin filament) combines through cross-bridges withmyosin (located in the A band and the major constituent of the thick filament) to form ac-tomyosin. The filaments are built up by the so-called myofibrillar proteins (94).

The protein matrix in muscle has a marked effect upon its functionality and proper-ties. The contractile myofibrillar proteins are recognized as essential for the characteristictextural properties of emulsion-type sausage such as bologna (95). Two major protein com-ponents, actin and myosin, which together account for about 70% of the weight of the my-ofibril, are those involved in the gelation of processed meat products (96).

4. Water

Water is the major constituent of muscle; it accounts for at least 75% by weight of fresh tis-sue. The bulk phase water in muscle tissue is located (a) within the filament, (b) in the in-terfilamental spaces, and (c) in the extracellular space. According to the form of binding,water in meat is classified as strongly bound (hydrational), immobilized, and “free”(97,98). Of more importance than the total amount of water present is the water holding ca-pacity (WHC) of the tissue or the ability to retain its own water during processing.

a. Bound Water. The water within the filament is primary a result of its associ-ation with myofibrillar protein through hydrogen bonding. It has long been appreciatedthat the binding of water to the surfaces of protein molecules is too small to account forthe observed changes in water content (99). The weight fraction of protein in meat isabout 20%, and proteins are commonly believed to bind water only to the extent of theorder of 0.5 gram of hydration water per gram of protein (97). A relatively small part ofthe tissue water (4% to 5%) is tightly bound on the surface of the protein molecules ashydration water. Water actually bound to protein molecules therefore represents a smallfraction of the total water present (98). It is estimated that only a very small part of themuscle water is present as “constitutional water” (about 0.3 g H2O/100 g protein, i.e.�0.1% of the total tissue water) which is located within the protein molecule (100).

b. Immobilized Water. In addition to the bound water, it was postulated that in-trafiber water may possess the ability to reduce adhesive force between the myofibrils.Capillary water, which is entrapped in myofibrils within muscle membrane, deserves spe-cial interest for intermediate-moisture meat products. Changes in WHC are closely relatedto pH and to variations in muscle proteins (101). It is reasonable to suppose that water is



held in muscle by capillarity, mostly in the interfilamental spaces within the myofibrils, butthat a substantial part also exists in the spaces between the myofibrilar and in the extracel-lular space. Bulk-phase water is immobilized within the microstructure of the intact orcomminuted tissue (102). The muscle protein molecules in an aqueous solution interactwith water, and when it moves through the solvent it carries some water with it. Part of thisbound water is believed to be hydrogen-bonded to the surface of the protein molecule,while most of them may be present in clefts or pockets (103).

It is generally accepted that a further part of tissue water (5% to 15% of the total wa-ter) shows a relatively restricted mobility (94). About 10% of the total water in the livingmuscle must be associated with the extracellular space. It is supposed that about 80% of thewater in the muscle fiber would be in the myofibrillar space and about 20% in the sar-coplasm. The muscle fiber is covered by the sarcolema, the cell membrane. The membranesof the sarcolemma and the sarcoplasmic reticulum consist of proteins of the connective tis-sue type (104).

Among physical stabilization factors in meat mixtures, the heated protein gel matrixis generally recognized as the predominant factor controlling water retention. Gelation ofmeat proteins during heating takes place to some degree in all products. It first involves un-folding, then the interlinking of muscle proteins to form a three-dimensional continuousnetwork (105). The myofibrillar proteins, myosin and actin, are the building components ina three-dimensional network. Within the three-dimensional protein network a large amountof water is absorbed (106,107). The moisture mobility in frankfurter emulsions duringcooking. They suggested that the bulk of unbound moisture is fixed in the gel matrix (108).A large amount of water is retained within the three-dimensional protein network of man-ufactured sausage batters (109).

5. Isotherm

Isotherms appear to be related to different modes of water binding (110). IM meats aremulti-component systems. The isotherms of the meat or meat mixture show a relationshipof averaged moisture content and the common water activity (33).

In reconsideration of the aw measuring techniques, it was suggested that measuringthe water vapor pressure (i.e. isotherm) is a better index of water binding by muscle. Ofgreat importance in IM meats are the sorption properties of the muscle components (33).The possibility of using the Guggenheim-Anderson-De Boer (GAB) equation to delineatethermodynamic aspects of moisture sorption behaviour in basturma, a traditional Mediter-ranean intermediate-moisture meat product, was studied (28). For aw values between 0.4and 0.9 and with mean relative deviation modules values of 5%, the GAB equation gavesatisfactory goodness of fit. Moisture sorption characteristics of spiced and nonspiced kil-ishi (a Nigerian sun-dried meat product prepared from beef, mutton, or goat meat) were alsoinvestigated. A BET type III behavior between aw of 0.10 and 0.96 was described, and hys-teresis was exhibited.

Four sorption models (Oswin, Halsey, Iglesias and Chirife, and Guggenheim-Ander-son-de Boer) used to predict the sorption characteristics of kilishi were found not to be assuitable as an exponential model in predictive ability (28,110). GAB monolayer moisturecontents and the constants in the exponential model were temperature-dependent. Spicedproducts had higher equilibrium moisture contents and their monolayer values were higher.The practical importance of the sorption properties of kilishi is noted. These equations canbe used to determine the proper extent of product dehydration for safe storage, increased

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product yield, and improved sensory quality. Sorption isotherm was used to predict the crit-ical moisture content for storage of biltong (111).

The Halsey equation gave higher mean relative deviation modules values, indicatingthat this isotherm model has limited ability to describe moisture sorption behavior of thespecific product. The utilization of the sorption data for predicting dehydration require-ments and product stability of commercially produced basterma has been reported (28).Moisture sorption isotherms of thin slices of basturma were determined using the staticmethod with saturated salt solutions. Desorption isotherm data were used to predict the ex-tent of dehydration required to reach the desired aw.

The soluble solids in the amorphous state absorb more water than that of the musclesolids within a water activity range of IM meats. In production of IM meats, in addition toselecting raw muscle with good sorption properties, one should try to modify the shape ofthe isotherm in the meat by formulation (adding sugar and/or salt). Addition of these non-meat ingredients such as sugar and salt changes the sorption phenomena of the meat solidin Zousoon processing (33). In the range of aw 0.60 to 0.90, which is equivalent to an openstorage relative humidity of 60% to 90%, the meat product has a higher moisture contentthan that of the muscle alone. This phenomenon was attributed to the altering structure ofthe solid matrix, such as developing a gel or capillary structure. It was further pointed outthat it is the intact muscle cell with membrane with its selective barrier characteristics thatretained the water.

IV. EFFECT OF HEATING ON PHYSICOCHEMICAL PROPERTYCHANGES DURING INTERMEDIATE-MOISTURE MEATPROCESSING

A. Proteins

For isolated muscle protein, Differential Scanning Calorimetry (DSC) has long been usedto procure calorimetric data under dynamic conditions because the sample is heated at aprecise rate. This technique has been used to investigate meat proteins as influenced by pro-cessing (96,112). The three thermic peaks at 60°, 67°, and 80°C, through the use of the pu-rified proteins, were found to correspond to thermal denaturation of myosin, sarcoplasmicproteins, and actin, respectively. It was postulated that the second peak also includes thecontribution of the thermal transition of collagen (112). Protein denaturation was followedby DSC analyzing peaks for myosin (I and II), ] sarcoplasmatic proteins and collagen andactin (113). Three endotherms were observed for post-rigor bovine semimembranous meat(Tmax at 57°, 66°, and 80°C) (114).

The temperature range of maximum changes in the solubility of myofibrillar proteinsseems to be about the same in the intact muscle fiber as in the isolated state (114). Changesof tenderness, rigidity, and water-holding capacity of beef muscle on heating occurs in twophases: the first phase is between 30° and 50°C and the second is between 60° and 90°C.In the temperature range between 50° and 55°C, negligible changes occur. Changes in thefirst phase are due to heat coagulation of the actomyosin system. The second phase seemsto be due to denaturation of the collageneous system (shrinking and solubilization of col-lagen) and/or to the formation of new stable cross-linkings within the coagulated acto-myosin system. In the temperature range between 50° and 55°C, the coagulation of my-ofibrillar proteins is almost completed, but remarkable changes in connective tissue proteinhave not yet started (115).



B. Sausages

The gel formation of myofibrillar proteins (mainly actomyosin) is of particular importancein emulsion-style sausage. A protein matrix is necessary for the desired texture and aw levelof fermented sausages. The formation of this network is predominantly induced by myosinand actin proteins (116). After comminuting, the cell wall (sarcolemma) of the musclefibers is, in great part, destroyed (117). A large exudate issues from the cell after rupture ofthe plasma membrane. During chopping, with simultaneous release of meat proteins, thesalt brings about a change in the original structure of proteins by swelling and partial solu-tion of myofibrils (100). The dissolved proteins are transformed into a thin fluid colloidaltransition state.

As a matter of fact, a meat batter is not considered a true emulsion. A meat batteris actually a very complex mixture consisting of suspended particles (collagen fibers,myofibrils, cellular organelles), immobilized and free water, lipid droplets and particles,and hydrated, solubilized and non-solubilized myofibrillar proteins. The decreases in sol-ubility of myofibrillar proteins between 30° and 60°C is accompanied by an unfolding ofthe protein chain. Probably an association of the unfolded peptide chain causes proteincoagulation (115). A thin coating adhesive substance of meat proteins may cover thesurfaces of all particles in the meat batter and binds them (118). During sausage ripen-ing, as a result of denaturation by lactic acid and due to gradual loss of water (drying),the unstable bonds are replaced by condensation bonds and lead to a gel formation (116).The gradual drying during ripening of fermented sausage result in a gel solidification atthe edge of the particles. The water in a sausage is postulated to be associated with themyofibrillar protein molecules, or more precisely be entrapped in the actomyosingel (119).

For a stable intermediate-moisture sausage, a low heating or smoking temperature isrecommended. Heat coagulation of myofibrillar proteins may reduce the water-holding ca-pacity. The greatest decrease in the solubility of myofibrillar proteins during heating ofmeat occurs at temperatures between 40° and 60°C; above 60°C, these proteins become al-most insoluble (120).

V. PARAMETERS CONTROLLING THE STABILITY OFINTERMEDIATE-MOISTURE MEATS

Intermediate-moisture foods normally range in aw from 0.7 to 0.9 and in water content from20% to 50% (121). The aim of aw controlling in IMM is to reduce the aw of a meat productto a range in which most bacteria in foods will no longer grow (76). As pointed out previ-ously, bacteria, other than halophiles, will not grow at 0.83 aw or below, and most are in-hibited markedly at 0.90 aw or less. Intermediate-moisture meats are stabilized by loweringtheir aw to a level insufficient to support bacterial growth, typically about 0.85. Molds andyeasts are able to grow at these aw values and it is usual to add an antimycotic such as sor-bate to ensure microbial stability (120,122).

Sausages, such as salamis, have a relatively high aw of 0.85 to 0.95 (123). These prod-ucts rely on a combination of factors for their microbial stability—e.g., nitrite, reduced pH,addition salt, reduction of redox potential by vacuum packaging, and sometimes a heattreatment during manufacturing. However, dried meats made from whole muscle, such asbiltong and Chinese dried meat products, rely primarily on reduction of aw for their stabil-ity (56).

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A. Heating

The thermal process is among the most important factors controlling the microbialcontent and stability of the finished product (124). It seems clear that humansfirst learned the drying and smoking of meat. The preservation of foods by dryingallowed early humankind to survive in times of food scarcity and to separate themselvesfrom their food sources during periods of migration. It is a widespread art practiced inpre-Columbian, ancient Eskimo, Mediterranean, Oriental, and African cultures. Sundrying is probably the oldest dehydration technique known and is still practiced in vari-ous parts of the world. Heating may result in a significant structural change of muscletissue. This procedure requires that drying be sufficiently rapid to reduce aw to a levelat which microbial growth will not occur before drying is complete. Accordingly, micro-bial destruction that might occur during the smoking process would be due to antimicro-bial properties of the smoke and further dehydration at the surface of the meat. Later, theuse of salt in conjunction with drying and smoking of meat as a preservative wasdiscovered.

B. Salt

Several solutes serve as safe and effective agents for reducing aw levels in IMM. Sodiumchloride and sucrose have been the most widely used for this purpose. The preservation offood by salting is nearly as old as sun drying. An adequate aw for preservation in aerobicconditions is �0.7, achieved preferably by sugar or salt addition and dehydration. Criteriafor producing shelf-stable and intermediate moisture meat products by using hurdle tech-nology are surveyed with the aid of examples (biltong, Chinese dried meat) by Tannahill(125).

Commerce in salt by ancient Egyptian, Chinese, and Phoenecian culture is well doc-umented (126). Salt has long been used not only as a preservative but also as flavor en-hancer. Sodium chloride is used mainly to reduce aw in meat products for human con-sumption, such as salt-cured hams, bacon, and some types of sausages. Brining continuesto be an important method of curing hams. The relatively high NaCl content and drying hada major effect on spread of bacteria in pasterma.

The manufacture of ‘charqui’ (a salted dried meat consumed in Chile and other SouthAmerican countries) from low-quality beef by hot air drying was studied (127). Beef neckmuscles were pretreated with 15% or 25% brine, immersion time 16 or 24 h. Investigatorsfound the only important parameter was brine concentration, which produced a significantincrease in weight at the lower concentration. Total weight loss during drying was 51% to56% (fresh meat basis) or 47% to 52% (salted meat basis) at 30°C, 63% to 66% and 61%to 65%, respectively, at 50°C. Final moisture content was 21.2% for the product dried at30°C, 5.7% at 50°C.

The NaCl content of ham-curing brines normally ranges between 60% and 70% ofsaturation (0.87 to 0.82 aw) (128). Brines usually are pumped into the vascular system ofthe ham and along the bone, followed by total immersion into the brine prior to trimmingand smoking. Bacon (129) is normally processed in a similar manner. Considering foodswith aw from 0.60 to 0.91 to be intermediate-moisture foods, aw, pH, and some chemicalparameters (moisture, protein, fat, ash, NaCl, and non-protein N) were determined for 70samples of 17 types of Spanish intermediate-moisture meat products. It was concluded thatNaCl is the main aw depressor (35).



C. Sucrose

The microbial stability of Chinese IM meats is due mainly to the rapid reduction of aw (55).This is aided by the addition of a significant amount of sugar (15% to 35% dry basis). Pro-duction technologies for several Malaysian low- and intermediate-moisture traditionalmeat products (shredded sliced beef, spiced beef slices, Chinese sausage, meat floss) andproblems related to keeping them under Malaysian conditions (mold growth and ranciditydevelopment) were investigated (20). These IM meats technically are similar to those Chi-nese-style meat products. Traditional Indonesian dendeng has a moisture content and aw

low enough to prevent microbiological spoilage. This microbial stability could be at-tributed to its high sugar content, which reduces the water activity of the finished products.Higher-moisture dendeng, however, can spoil due to mold growth (19).

In addition to its water activity–lowering effect, amorphous sucrose contributes to theplasticized texture in Chinese IM meat (55). It was reported that sucrose (added to slicedpork) contributed to the softening of dried pork by drying the tissue uniformly, due to re-duction of its drying rate, as well as by preventing muscle protein from excessive aggrega-tion. Stiffness of the dried pork decreased with increasing sugar concentration; the decreasewas significant if sucrose was added (130). Newly developed IM meats are often not suffi-ciently palatable, contain too many additives (“chemical overloading” of the food), andpose legal problems because of the need to obtain approval of new additives (131).

D. Chemicals

Bacteriologically, Egyptian fresh sausage might pose a potential health hazard, making itimperative to investigate sanitary measures during its production and sale (27). Dry curedhams produced commercially in North America have a good record of safety. The majorcause of spoilage of finished dry cured products is yeast and mold growth during storage inconditions of high humidity. The microbiological stability of finished dry cured meats isthe result of their low water activity and the presence of nitrite (132). The microbial stabil-ity of short-ripened products depends primarily on a combination of a low pH (below 5.3)and relatively low aw (�0.95); in fermented sausages with a long ripening time, the aw islow (0.80 to 0.90) and the pH is relatively high (5.7 to 6.5) (133).

E. Intact-Muscle IM Meat

For some IM meat products such as Chinese ruogan and Indonesian dendeng, the gel for-mation of the solubilized collagen for structure and water activity is important. The gela-tion process occurs in two steps. In the first step, more or less collagen is transformed tosoluble gelatin; then, during heating, a new helicoidal structure is formed (134). Denatura-tion of muscle collagen occurs at higher temperatures than the denaturation of myofibrillarproteins. The soluble gelatin seems to bind the muscle fiber together to form an intact struc-ture. Muscle structure by SEM showed shorter sarcomeres, reflected in increased toughness(84). The structure of meat treated with brine was examined under light and electron mi-croscopes, and only a few muscle cells at the surface of the meat were found altered (135).The process used in the transformation of raw animal tissue into a traditional Chinese IMmeat was found to preserve to a great degree the initial cellular structure of the material.The material can be considered made of a matrix, usually water insoluble, intact cell mem-brane, and a complex aqueous solution of sugars, amino acids, proteins, salts, and lipids.The cell membranes play a major role in the water retention in IM meats (135). Collagen

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fiber in cooked bovine M. sternimandibularis muscle undergoes a thermal contractionwhen heated to 65°C (136). This is brought about by a collapse of the tertiary structure ofthe collagen molecules, converting them from highly organized triple helices to randomcoil configuration. The perimysium contains mainly Type III collagen (137), which has ashrink temperature of 64°C (138). The binding of the myofibrils in cooked fibers were ob-served (139). Initially, they part as intact fibers with interfiber strands of collagen fibers,which then rupture on further extension. These strands are the weak points in the structure.Recent studies (140) have indicated they are composed mainly of denatured collagen (i.e.,gelatin). The partial solubilization of the endomysial collagen of bovine muscle is initiatedat about 60°C and completed at approximately 70°C, whereas perimysial connective tissuesolubilizes at a higher temperature.

Effects of heat-drying on properties of myofibrils from pork were examined, togetherwith the relationship between myofibril characteristics and pork texture (141). It is sug-gested that contractile protein starts to denature very early in drying, and then moisture be-gins to continuously decrease. Results imply that dried pork would be tender if denatura-tion of contractile protein could be prevented during drying. The temperature employed fordrying and smoking must be sufficiently low to retain the raw texture of the meat and notinactivate the inherent enzymes involved in flavor development during aging.

The muscle fiber is cover by the sarcolema, the cell membrane. The membranes ofthe sarcolemma and the sarcoplasmic reticulum consist of proteins of the connective tissuetype. Thus the plasma membrane of the muscle fiber is easily perforated by freezing andthawing (88). Electrical stunning of hogs causes fragmentation and breakage of the musclefibers (34); this can explain why for all Chinese dried meat processes, hot-boned meat ispreferred (33,142). A cellular food, such as intact animal tissue, has a definitive structureand some rigidity at drying temperatures (143).

The thermal contraction of the peri- and endomysial collagen during cooking resultsin compression and loss of water from the denatured actomyosin fiber. Light microscopyshowed considerable shrinkage of muscle cells and formation of fluid channels (9). Thearea occupied by muscle cells in jerked beef was 30% to 40% less than in fresh beef. At theultrastructural level, A-bands (including the M-line) disappeared, indicating that proteinswere lost during processing. Z-lines appeared to be fragmented. In the enlarged extracellu-lar spaces, banding patterns of collagen fibers were retained; empty spaces surroundedthese fibers. It was concluded that denaturation of myofibrillar proteins during processingand the osmotic pressure caused by salting create conditions for water movement from themyofibrillar compartments to the intermyofibrillar space, then to the extracellular matrix,and ultimately to the meat surface (139).

F. Sausages

The growth of microorganism that predominate on fresh meat is readily inhibited by pH 5.5and by salt concentrations in the range of 5% to 8%, and the combined effects that occur inprocessed meats are even greater than either condition alone (144). Factors affectinggrowth in cured meats and some of the consequences of their growth was reviewed (141).Salmonellae, Clostrdium botulinum, C. perfringens, and Staphylococus aureus have beenrecognized as major types of pathogens involved in foodborne disease, with Streptoco-cocci, Bacillus cereus, Vibrio spp., enteropathogenic Escherichia coli, and other organismare also of concern. Attention also has been given to the newer potential pathogens,Yersinia enterocolitica and Campylobacter species (144).



Studies were conducted on the possibility of reduction of the quantity of NaCl usedin the manufacture of raw dry ham and dry sausage, and hence the sodium content of thefinal products. For ham, data are given showing the relation of aw and temperature togrowth of spoilage bacteria (Proteus vulgaris, Enterobacter agglomerans, Serratia lique-faciens and Clostridium botulinum). These results showed that if reduced levels of NaClare to be used, NaCl distribution within the ham must be uniform, maturation temperaturemust be sufficiently low to prevent bacterial growth at the NaCl concentration used, andmoisture loss from the product during curing and so forth must be increased above currentlevels. Results for dry sausages show that reduction of NaCl content in combination withacetic acid and KCl may give acceptable results; consistency of the product may, however,be affected (142).

In order to secure the expected stability and safety, the aw of those IM meat prod-ucts that are not heated to a higher temperature during the processing and are consumedraw has to be low, in the range of 0.84 to 0.94, depending on the drying process used andthe actual pH value. The use of starters in the manufacture of meat products, particularlyfermented sausages, is discussed with reference to new developments (146). Comminu-tion of meats used in fermented sausages improves distribution and diffusion of startersin comparison to whole cured meats (e.g., dried ham). Contributions made by microor-ganisms to the cured meat product are considered and include the following: (a) nitratereduction by Micrococcaceae; aroma formation by Micrococcaceae, Streptomycesgriseus, and yeasts; (b) visual appeal due to presence of surface molds (non–mycotoxinforming), e.g. Penicillium chrysogenum and P. nalgiovensis; and (c) color developmentand product consistency due to Lactobacillus and Pediococcus spp. New developmentsconcerned with the prevention of spoilage in meat products include optimization ofstarters, improving product resistance to spoilage, and the use of bacteriocin-producingmicroorganisms. The use of starters in dried meat is less effective than in sausages be-cause of high salt levels and low distribution. New developments for this industry includeselection of salt-resistant strains of microorganisms and improved enzyme systems thatensure effective microorganism concentration.

G. Innovative Water Activity Control Technology

Previous study has shown that microbially stable glycerol/salt desorbed meat can be easilyand cheaply prepared (147). Traditionally, in Nigeria, fresh meat is precooked in waterwithout adding any ingredients, spices, or preservatives and hot-smoked to yield hard, des-iccated, and sometimes brittle products. It was demonstrated that smoked meat productscan be made by incorporating glycerol and other preservatives into products. Theorganoleptic quality of the traditional Nigeria smoked meat products can be improved(148).

There is a developing consumer demand for softer, lighter-colored, less sweet driedmeats. A new Chinese dried meat product, shafu, was developed to meet these require-ments (3). Meat (beef, pork or mutton) is cut into 200 g pieces, cured with a special mix-ture, steam-cooked for 40 to 60 minutes to a core temperature of 80° to 85°C, cooled, cutinto strips 0.3 cm thick, and dried at 85° to 90°C to a moisture content of less than 30%.Water activity is less than 0.79, generally between 0.74 and 0.76. If vacuum packaged, itmay be stored without refrigeration. Sensory, physicochemical, and microbiological prop-erties are compared with those of traditional products. Factors of importance for microbio-logical stability of shafu are discussed in relation to the hurdle technology concept.

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Glycerol reduced aw and moisture levels of IM meat and increased water holding ca-pacity; hardness, springiness, and chewiness were reduced by glycerol, and color was af-fected. Glycerol increased levels of Ca-activated factor activity in IM meats (149). A pro-cessing procedure was standardized by infusion soaking of buffalo meat samples in asolution of humectants: glycerol (2.0%) and sodium chloride (10.0%), chemical preserva-tives: trisodium citrate (2.0%) and sodium benzoate (0.2%) followed by milk heat treat-ment and air drying. Mean % net yield of IM product was 49.67. Samples revealed pH inthe range of 5.72 to 5.79, aw of 0.84 to 0.88, % moisture of 47.52 to 42.73, and % residualsalt content of 10.97 to 9.58. Sensory evaluation indicated no spoilage in the IM meat sam-ples during ambient temperature storage for 2 months, with acceptable palatability (150).An intermediate-moisture meat product (aw � 0.7) is prepared by cutting meat into smallpieces and treating it with an edible humectant (e.g., a sorbitol/NaCl preparation), option-ally at approximately 50°C. The resulting meat product may be used as a constituent or fill-ing in bakery products (151).

Functions of soluble and insoluble solids as aw depressants in alginate restructuredbeef heart meat (BHM) were evaluated (152). Water activity, pH, bind and moisture of al-ginate restructured BHM were evaluated using a 25-factorial design based on combinationsof beef heart meal and glycerol (10%, 20%), and dextrose, bone meal, and glycine. The ef-fects of these components were significant (P � 0.05). Use of 20% glycerol in the formu-lation enhanced overall quality by reducing pH, depressing aw, enhancing bind, and reduc-ing moisture content compared to products containing 10% glycerol. However, 20% to30% glycerol was reported to impart a bitter flavor. Glycine lowered aw and moisture con-tent but weakened binding in alginate-restructured BHM. Dextrose and dried BHM re-duced aw and did not affect bind. Bone meal strengthened bind and reduced moisture con-tent in intermediate-moisture meat products. The aw of the BHM control was 0.94, whereasaw for 32 treatments ranged from 0.66 to 0.90. It was concluded that an intermediate-mois-ture BHM product could be formulated using the hurdle concept and the alginate systemfor restructuring meat with incorporation of selected soluble (glycerol, dextrose) and in-soluble (beef heart meal, bone meal) components.

Glycerol, glycerol-nitrite and nitrite-based intermediate moisture (IM) buffalo meatswere prepared by 24 hr equilibration in their respective infusion solutions, then oven-heated and air-dried (153).

Meat patties were prepared from minced meat, with the addition of NaCl and potas-sium sorbate, and dried at 75°C for 11 hrs. Results showed that dried meat patties were sta-ble (154): No detectable changes were observed in the product during the first 2 months,according to chemical and bacteriological results. Organoleptic evaluation showed that theproduct was acceptable. Reports have been presented on meat products with extended shelflife (due to reduced water activity values) as manufactured primarily in Europe (such prod-ucts as salami, landjaeger, and buendnerfleisch) and more recently in the United States. Theuse of additional preserving agents, especially sorbic acid, is being considered as well asthe traditional use of low pH and aw values and smoking.

Preparation of intermediate-moisture meat (beef, pork, chicken, rabbit) by osmoticdehydration at 4° or 25°C with a Shona Denko contact dehydration sheet was developed(155). Osmotic dehydration at 4°C gave better retention of the native state of proteins,and hence better quality, than drying at 25°C. Dehydration at 4°C resulted in maintenanceof much of the original muscle structure; isolated myofibrils retained contractibleactivity. Myosin could easily be extracted after 10 days storage. Species differed little inresponse to osmotic dehydration. Dehydration with osmotic dehydration sheets at low



temperature permits production of a high-quality, low-salt intermediate-moisture meatproduct (155).

A gradual decrease in microorganism count during processing and storage of charquiwas observed. These results indicate the feasibility of obtaining a final product with a lowmicrobial count when raw materials of good quality, and adequate handling conditions, areused for charqui production (10). Use of the ingredient optimization program allowed pro-duction of a satisfactory Cervelat sausage by improved economical means (36).

Recently, the procedure for processing traditional dried beef into Kilishi was opti-mized (156). Wheat flour was added to the traditional sauce (a mixture of ground paste, wa-ter, and spices) to improve sauce adhesion to the dried meat. The coated beef was grilledfor 10 min (5 min each side such as traditionally done in Niger) using a household grill. Astable end-product with good keeping qualities of kilishi was obtained.

VI. CONCLUSIONS

Intermediate-moisture and dried meat products have been produced by various methods indifferent cultures through the centuries. It is interesting to know that these methods arefairly similar. By controlling the amount of salt, sugar, nitrate/nitrite, and other ingredients,as well as the curing, dehydration, and maturation times, and proper packaging and storageconditions, these products can be highly acceptable, fairly stable, and safe. The principlesbehind these techniques are being revealed by the various scientific studies on the effect ofingredients and processing methodology used in the preparation of these products. Thesafety of these products had been investigated extensively. The term “hurdle technology”probably describes these principles best nowadays. Consumers always demand better,safer, and more convenient products; scientists are being challenged to develop the inno-vative technologies to meet these demands.

REFERENCES

1. AH Varnam, JP Sutherland. Meat and Meat Products. New York: Chapman & Hall, 1995, pp167–412.

2. AM Jiang, YH Yuan, XJ Lian, ZM Liu. Methodology for classification of meat products. MeatRes 3:27–30, 1997.

3. W Wang, L Leistner, L. Shafu. A novel Chinese dried meat product based on hurdle technol-ogy. Fleischwirt 73 (8):867–869, 1993.

4. L Leistner, HK Shin, H Hechelmann, SY Lin. Microbiology and technology of Chinese meatproducts. Proceedings of the European Meeting of Meat Research Workers, No. 30, 6:11,280–281, 1984.

5. DR Smith. Effects of rigor state, salt level and storage time on chemical and shelf-stable in-termediate moisture meat products. Food Res Report, CSIRO, 44 (1):12–19, 1984.

6. DA Ledward. Intermediate moisture meats. In RA Rowrie, ed. Development in Meat Sci-ence—2. London: Applied Sciences, 1981, pp 159–194.

7. C Kellar, P Ossent, E Schlapfer. Damaged meat sections in production of dried meat products.Effects, significance and causes. Fleischwirtschaft 68 (1):36–40, 70, 1988

8. JR Romans, PT Zielgler. The Preservation and Storage of Meat. In: TR Romas, PT Zielgler,ed. The Meat We Eat. Danville: The Interstate Printer & Publishers, Inc, 1997, pp 559–611.

9. TMB Biscontini, M Shimokomaki, SF Oliveira, TMT Zorn. An ultrastructural observation oncharquis, salted and intermediate moisture meat products. Meat Sci 43 (3/4):351–358, 1966.

10. EAFS Torres, M Shimokomaki, BDGM Franco, M Landgraf, BC Carvalho Jr., JC Santos. Pa-rameters determining the quality of charqui, an intermediate moisture meat product. Meat Sci38 (2):229–234, 1994.

436 Huang and Nip


11. GA Norman, OO Corte. Dried salted meats: charque and carne-de-sol. FAO Animal Produc-tion and Health Paper No 51. 1985, 32 pp.

12. BI Crocombe. The development and production of jerky at MIRINZ’s meat products centre.Meat Industry Res Inst New Zealand Publications No. 855, 1988, pp 122–125.

13. Anon. The cowboy’s snack is back. Snack Food 59 (4):46–49, 1970.14. Anon. Care for some biltong or jerky? Rural Res 103:30–31, 1979.15. G Andujar, C Valladares. Study of a traditional intermediate moisture meat product: ‘Tasajo’.

I. Processing method and chemical composition. Proc Intl Congress of Meat Sci Technol No.35(III):833–839, 1989.

16. PA Sopade, ES Ajisegiri, AB Abass. Moisture sorption isotherms of kilishi, a traditional Nige-rian meat product. ASEAN Food Jour 10 (1):30–38, 1995.

17. JO Igene. Lipid, fatty acid composition and storage stability of kilishi, a sun-dried meat prod-uct. Trop Sci 28 (3): 153–161, 1988.

18. ZA Obanu. Preservation of meat in Africa by control of the internal aqueous environment inrelation to product quality and stability. In: CC Seow, TT Teng, CH Queh, ed. Food Preser-vation By Moisture Control. London: Elsevier, 1988, pp 161–173.

19. KA Buckle, H Purnomo, S Sastrodiantoro. Stability of dendeng. In: CC Seow, TTTeng, CHQueh, ed. Food Preservation By Moisture Control. London: Elsevier, 1988, pp 137–148.

20. EC Chuah, QL Yeoh, ABH Hussin, Traditional Malaysian low and intermediate moisturemeat products. In: CC Seow, TT Teng, CH Queh, ed. Food Preservation By Moisture Control.London: Elsevier, 1988, pp 149–159.

21. KA Buckle, H Purnomo. Measurement of non-enzymatic browning of dehydrated and inter-mediate moisture meat. J Sci Food Agric 37 (2): 165–172, 1986.

22. T Yasui, P Binotoro, T Nagahashi, J Morita. Studies on Indonesian-style experimental driedbeef. Nippon Shokuhin Kogyo Gakkaishi 34 (11): 764–770, 1987.

23. I Garcia, JM Zumalacarregui, V Diez. Microbial succession and identification of Micrococ-caceae in dried beef cecina, an intermediate moisture meat product. Food Microbiol 12 (4):309–315, 1995.

24. R Reyes-Cano, L Dorantes-Alvarez, H Hernandez-Sanchez, GF Gutierrez-Lopez. A tradi-tional intermediate moisture meat: beef cecina. Meat Sci 36 (3): 365–370, 1994.

25. WB Van der Riet, WB. Biltong-a South African dried meat product. Fleischwirtschaft62:1000–1001, 1982.

26. James, G. V. A note on some concentrated animal high protein foods. J Assn Public Analysts24 (4): 141–142, 1986.

27. T El-Khateib. Microbiological status of Egyptian salted meat (basterma) and fresh sausage. JFood Safety 17 (3): 141–150, 1997.

28. HN Lazarides, H. N. Sorption isotherm characteristics of an intermediate moisture meat prod-uct. Lebensmittel-Wissenschaft und-Technologie 23 (5): 418–421, 1990.

29. P Neumann. Use of freeze-dried meat in large-scale industrial raw sausage manufacture. Fleis-cherei 34 (5): 415–418, 1983.

30. A Stiebing, R Becker. Influence of freeze-dried meat on the ripening of fat-reduced beefsalami. Fleischwirtschaft 75 (11): 1311–1316, 1330, 1995.

31. VR Redden, T Chen. The potential of Chinese meatballs and dried meat as value added PSEpork products. Food Australia 47 (7): 323–326, 1995.

32. SF Chang, TC Huang, AM Pearson. Control of the dehydration process in production of in-termediate moisture meat products: a review. Adv Food Nutr Res 39: 71–161, 1996.

33. SF Chang, TC Huang, AM Pearson. Some parameters in production of zousoon—A semi-dry,long fibrous pork product. Meat Sci 30:303–325, 1991.

34. SF Chang, AM Pearson. Effect of electrical stunning or sticking without stunning on the mi-crostructure of Zousoon, a Chinese semi-dry pork product. Meat Sci 31: 309–326, 1992.

35. MB Gailani, DYC Fung. Critical review of water activities and microbiology of drying ofmeats. CRC Crit Rev Food Sci Nutr 25 (2): 159–183, 1986.



36. J Fernandez-Salguero, R Gomez, MA Carmona. Water activity of Spanish intermediate mois-ture meat products. Meat Sci 38 (2): 341–346, 1994.

37. R Todorov, E Markov, N Tyutyundzhiev. Manufacture of coarse-ground dried meat productsof a programmed composition. Proc Euro Mtg of Meat Res Workers 33(II): 432–434, 1987.

38. A Porter, GMbH Dedderer. Trails for industrial production of dry sausage from freeze-driedmeat (in German). Fleischwirtschaft 57 (6): 1150–1153, 1997.

39. International Commission on Microbial Specifications for Foods (ICMSF). Microbial Ecol-ogy of Foods. New York: Academic Press, 1980, Vol. 2, pp 333–409.

40. CO Gill. Total and intramuscular bacterial population of carcasses and cuts. Proc Annu. Pro-ciprocal Meat Conf 33: 47–53, 1980.

41. RB Maxcy. Surface microenvironment and penetration of bacteria into meat. J Food Prot 44:550–552, 1981.

42. JA Harrison, MA Harrison, RA Rose. Survival of Escherichia coli O157:H7 in ground beefjerky assessed on two plating media. J Food Prot 61 (1): 11–13, 1998.

43. MO Hanna, JC Stewart, DC Zink, ZI, Carpenter, C Van-Derzant. Development of Yersinia en-tercolitica on raw and cooked beef and pork at different temperatures. J Food Sci 42:1180–1184, 1997.

44. WJ Scott. Water relations of Staphylococcus aureus at 30°C. Aust J Biol Sci 6: 549–564, 1953.45. WJ Scott. Water relations of food spoilage microorganisms. Adv Food Res 7:83–128, 1957.46. WP Segner, CF Schmidt, JK Bolts. Minimal growth temperature, sodium chloride tolerance,

pH sensitivity, and toxin production of marine and terrestrial strains of Clostridium botulinumType C. Appl Microbiol 22: 1025–1029, 1971.

47. WP Segner, CF Schmidt, JK Boltz. Effect of sodium chloride and pH on the outgrowth ofspores of types of Clostridium botulinum at optimal and suboptimal temperature. Appl Mi-crobiol 14: 49–54, 1966.

48. RA Greenberg, JH Siliker, LD Fatta. The influence of sodium chloride on toxin productionand organoleptic break down in perishable cured meat inoculated with Clostridium botulinum.Food Technol 13: 509–511, 1959.

49. CK Kang, M Woodburn, A Pagenkopf, R Cheney. Growth, sporulation and germination ofClostridium perfringes in media of controlled water activity. Appl Microbiol 18: 798–805,1969.

50. HA Abdel-Rahman, H Yossef, Y Hefnawey, Y. Mycological quality of meat products inEgypt. Assiut Veterinary Med J 12 (24): 153–163, 139, 1984.

51. LW Van den Heever. The variability of salmonellae and bovine cysticerci in biltong. S AfrMed J 39: 14–16, 1965.

52. MB Taylor. Changes in microbial flora during biltong production. S Afr Fd Rev 3 (2):120–121, 1976.

53. HK Shin, L Leistner, H Hechelmann. Stability of traditional intermediate moisture meat prod-uct in a storage. Proc AAAP Animal Sci Congress 1985. 3 (2): 1156–1161, 1985.

54. JM Jay. Meats, poultry and seafoods. In: L Beuchat, ed. Food and Beverage Mycology. West-port: AVI. 1978. pp. 129–144.

55. JC Ayres, DA Lillard, L Leistener, L. 1967 Mold ripened meat products. Proc Annu Recipro-col Meat Conf 20: 156–168, 1967.

56. L Leistner, Shelf-stable products and intermediate moisture foods based on meat. In: LBRockl, LR Beuchat, ed. Water Activity: Theory and Applications to Foods. New York: Mar-cel Dekker, 1987, p. 295–323.

57. FT Bauer, JA Carpenter, JV Reagan. 1981 Prevalence of Clostridium perfrigens in pork dur-ing processing. J Food Prot 44: 279–283, 1981.

58. B Swaminathan, MAB Link, JC Ayres. Incidence of salmonellae in raw meat and poultry sam-ples in retail stores. J Food Prot 41: 518–520, 1978.

59. FL Bryan. 1980 Foodborne diseases in the United States associated with meat and poultry. JFood Prot 43: 140–150, 1980.

438 Huang and Nip


60. C Genigeorgis, S Lindroth. The safety of Basturma and Armenian-type dried beef with respectto salmonella. Proc Euro Mtg. Meat Res Workers 30, 5 (2): 217–218, 1984.

61. P Kotzekidou. Identification of staphylococci and micrococci isolated from an intermediatemoisture meat product. J Food Sci 57 (1): 249–251, 1992.

62. P Kotzekidou, HN Lazarides. Microbial stability and survival of pathogens in an intermediatemoisture meat product. Lebensmittel-Wissenschaft und -Technologie 24 (5): 419–423, 1991.

63. L Berkman. Uber die Haltbarkeit von Krankheitserregern in einem spezifisch turkischen Fleis-cherzeugnis. Fleischwirtshaft 40: 926, 1960.

64. HK Shin. Energiesparende konservierungsmethoden fur fleischerzeugnisse, abgeleitet vontraditionellen intermediate moisture meats. Ph.D. thesis, Universitat Hohenheim, Stutttgart-Hohenheim, West Germany.

65. LW Van den Heever. 1970 Some public health aspects of biltong. J S Afr Vet Med Assoc 41:263–272, 1970.

66. BA Prior, L Badenhorst, L. Incidence of salmonellae in some meat products. S Afr Med J 48:2532–2533, 1974.

67. BS Emswiler-Rose, RW Johnston, ME Harris, M.E. WH Lee. Rapid detection of staphylo-coccal thermonuclease on casings of naturally contaminated fermented sausages. Appl Envi-ron Microbiol 40: 13–18, 1980.

68. ME Stiles, LK Ng, DC Paradis. Survival of enterpathogenic bacteria on artificially contami-nated bologna. Can Inst Food Sci Technol J 12: 128–130, 1979.

69. ME Stiles, LK Ng. Fate of pathogens inoculated into vacuum packaged sliced hams to simu-late contamination during packaging. J Food Prot 42: 464–469, 1979.

70. WF Ng, BE Langlois, WG Moody. Fate of selected pathogens in vacuum-packaged dry-cured(country style) ham slices stored at 2 and 25 °C. J Food Prot 60 (12): 1541–1547, 1997.

71. Z Cvetnic, S Pepeljnjak. Aflatoxin-producing potential of Aspergillus flavus and Aspergillusparasiticus isolated from samples of smoked-dried meat. Nahrung 39 (4): 302–307, 1995.

72. L Leitner, W Rodel, K Krispien, K. Meat and meat products in high- and intermediate-mois-ture ranges. In: LB Rockland GF Stewart, ed. Water Activity: Influence on Food Quality. NewYork: Academic Press, 1978, pp 855–916.

73. MB Gailani, DYC Fung. Microbiology and water activity relationship in the processing andstorage of Sudanese dry meat (Sharmoot). J Food Prot 52 (1): 13–20, 30, 1989.

74. Lee, BB and Kraft AA. Microbiology of intermediate moisture pork. J Food Sci 42 (3):735–737, 1977.

75. TP Labuza, S Cassil, S. AJ Sinskey. Stability of intermediate moisture foods. 2. Microbiology.J Food Sci 37: 160–162, 1972.

76. M Plitman, Y Park, R Gomez, AJ Sinskey. Viability of Staphylococcus aureus in intermedi-ate moisture meats. J Food Sci 38: 1004–1008, 1973.

77. CEM Webster, DA Ledward, RA Lawrie, R.A. Effect of oxygen and storage temperature onintermediate moisture meat products. Meat Sci 6: 111–121, 1982.

78. F Wirth. Technology of manufacturing of fat reduced meat products. Fleischwirtschaft 68 (2):160, 162–165, 201, 1988.

79. I Bloukas, KO Honikel. The influence of additives on the oxidation of pork back fat and its ef-fect on water and fat binding in finely comminuted batters. Meat Sci 32: 31–43, 1992.

80. FS Wang, YN Jiang, CW Lin. Lipid and cholesterol oxidation in Chinese-style sausage usingvacuum and modified atmosphere packaging. Meat Sci 40: 93–101, 1995.

81. R Reyes-Cano, L Dorantes-Alvarez, H Hernandez-Sanchez, GF Gutierrez-Lopez. Biochemi-cal changes in an intermediate moisture cecina-like meat during storage. Meat Sci 40 (3):387–395, 1995.

82. DO Alonge. Carcinogenic polycyclic aromatic hydrocarbons (PAH) determined in Nigeriankundi (smoke-dried meat). J Sci Food Agric 43 (2): 167–172, 1988.

83. S Sisson, JD Grossman. The Anatomy of Domestic Animals, 4th ed. Philadelphia: WB Saun-ders Co, 1953.



84. DW Stanley, HD Geissinger. Structure of contracted porcine psoas muscle as related to tex-ture. Can Inst Food Sci Technol J 5: 214–216, 1972.

85. DW Stanley. Relation of structure to physical properties of animal material. In: M Peleg, EBBagley, ed. Physical Properties of Foods. Westport: AVI, 1983, pp 127–206.

86. C Frazini-Armstyrong. Membranous systems in muscle fibers. In: GH Bourne, ed. The Struc-ture and Function of Muscle. 2nd ed., Vol. II, Structure, Part 2. New York: Academic Press,1973, pp 532–619.

87. TK Borg, JB Caulfield. Morphology of connective tissue in skeletal muscle. Tissue Cell12:197–207, 1980.

88. RJ McCormick. 1995 Structure and properties of tissues. In: JF Price, BS Schweight, ed. TheScience of Meat and Meat Products. San Francisco: W.H. Freeman, 1995, pp 25–62.

89. ME Nimni, RD Harkness. 1989. Molecular structures and functions of collagen. In: MENimni, ed. Collagen, Vol. I, Biochemistry. Boca Raton: CRC Press, 1989, pp 1–77.

90. L Stryer. Biochemistry. San Francisco: Freeman, 1981.91. R Mayne, RE Gurgeson. Structure and Function of Collagen Types. Orlando: Academic Press,

1987.92. AJ Bailey, DT Restall, TJ Sims, VC Durance. Meat tenderness: immunofluorescent localisa-

tion of the isomorphic forms of collagens in bovine muscles. J Sci Food Agric 30: 203–210,1979.

93. DE Goll, RM Robson, MH Stromer. Muscle proteins. In: JR Whitaker, SR Tannenbaum, ed.Food Proteins. Westport: AVI, 1977, pp 121–174.

94. A Pearson, R Young. Proteins of the thick filament. In: A Pearson, RY Young, ed. Muscle andMeat Biochemistry. San Diego: Academic Press, 1989, pp 66–94.

95. GR Schmidt, RF Mawson, RF Siegel. Functionality of a protein matrix in comminuted meatproducts. Food Technol 35 (5): 235–237, 1981.

96. JR Quinn, DP Raymond, VR Harwalkar. Differential scanning calorimetry of meat proteins asaffected by processing treatment. J Food Sci 45, 1146–1149, 1980.

97. R Hamm. Kolloidchemie des Fleisches. Verleg Paul Parley, Berlin, Hamburg, Germany, 1972.98. KO Honikel. Water binding capacity of meat. Fleischwirtsaft 67: 418, 420, 422–423, 425, 428,

452, 1987.99. R Hamm. Biochemistry and Meat Dehydration. Adv Food Res 10:356–463, 1960.

100. R Hamm. Water-holding capacity of meat. In: JDA Cole, RA Lawrie, ed. Meats. Westport:AVI, 1975, pp 321–338.

101. O Fennema. Water and protein dehydration. In: JR Whitaker, SR Tannenbaum, ed. Food Pro-teins. Westport: AVI, 1977, pp 50–90.

102. G Offer, J Trinick J. On the mechanism of water holding in meat: The swelling and shrinkingof myofibrils. Meat Sci 8: 245–281, 1983.

103. G Offer, P Knight. The structural basis of water holding in meat. Part I: Drip Losses. In: R.Lawrie, ed. Developments in Meat Science-4. London: Elsevier, 1988, pp 173–243.

104. CF Hazlewood, DC Chang, BL Nicols, DE Woessner. Nuclear magnetic resonance transverserelaxation times of water protons in skeletal muscle. Biophys J 14: 583–606, 1974.

105. G Offer, P Knight, P. 1988a. The structural basis of water holding in meat. Part I: General prin-ciples and water uptake in meat processing. In: R Lawrie, ed. Developments in Meat Science-4. London: Elsevier, 1988, pp. 63–171.

106. J Wismer-Pedersen. Water. In: JF Price, BS Schweigert, ed. The Science of Meat and MeatProducts. San Francisco: Freeman, 1971, pp 177–191.

107. GS Mittal, JL Blaisdell. Weight loss in frankfurters during thermal processing. Meat Sci 9:79–88, 1983.

108. D Demeyer, A Verplaeste, M Gisteline. Fermentation of meat: an interacted process. ProcEuro Mtg Meat Res Workers 32 (1): 241–247, 1986.

109. LB Rockland, AK Nishi. Influence of water activity on food product quality and stability.Food Technol 34 (4): 42–50, 1980.

440 Huang and Nip


110. WB Van der Riet. Studies on the mycoflora of biltong. J South Afr Food. Rev 3: 105–111,1976.

111. DJ Wright, IB Leach, P Wilding. Differential scanning calorimetric studies of muscle and itsconstituent proteins. J Sci Food Agric 28: 557–564, 1977.

112. NC Bertola, AE Bevilacqua, NE Zaritzky. Heat treatment effect on texture changes and ther-mal denaturation of proteins in beef muscle. J Food Processing & Preservation 18 (1): 31–46,1994.

113. PJ Shand, JN Sofos, GR Schmidt. Differential scanning calorimetry of beef/kappa-car-rageenan mixtures. J Food Sci 59 (4): 711–715, 1994.

114. R Hamm. Influence of heating on animal tissues. Dechema Monograph, 56: 159, 1965.115. K Katsaras, KD Budras. Microstructure of fermented sausage. Meat Sci 31: 121–134, 1992.116. RW Currie, FH Wolfe. An assessment of extracellular space measurement in post-mortem

muscle. Meat Sci 8: 147–161, 1983.117. L Kotter, O Prandl. Physico-chemical processes in the manufacturing of dry sausage of good

cutting quality. Fleischwirtschaft 10: 26–28, 1958.118. L Kotter, G Terplan, C Gervasini. Physico-chemical processes in the manufacturing of slice-

able dry sausage. Fleischwirtschaft 14: 175–179, 1962.119. G Mutungi, P Purslow, C Warkup. Structural and mechanical changes in raw and cooked sin-

gle porcine muscle fibers extended to fracture. Meat Sci 40: 217–234, 1995.120. M Karel. Recent research and development in the field of low moisture and intermediate mois-

ture foods. Crit Rev Food Technol 3: 329–373, 1973.121. AD Hocking. Molds and yeasts associated with foods of reduced water activity: ecological in-

teractions. In: CC Seow, ed. Food Preservation by Moisture Control. London: Elsevier, 1988,pp 57–72.

122. DA Ledward. Stability of sorbic acid in intermediate moisture systems. Food Additives andContaminants 7 (5): 677–683, 714, 1990.

123. RB Tompkin. Microbiological techniques: sample transport, sample preparation, media andincubation. Proc Ann Reciprocol Meat Conf 29: 270–277, 1976.

124. J Vrchlabsky, P Dvorak, A Mikulik, A. Objective criteria for preservation of meat products.Prumysl Potravin 37 (3): 68–70, 1986.

125. R Tannahill. Food in History. New York: Stein & Day, 1973.126. CV Bifani, V. RC Paredes, M Vega, JA de la Vega. Dehydration of meat. Pretreatment and

drying conditions. Revista de Agroquimica y Tecnologia de Alimentos 24 (2): 239–248, 1984.127. RH Deibel, CF Niven Jr. Microbiology of meat curing. I. The occurrence and significance of

a mitile microorganism of the genus Lactobacillus in ham curing brines. Appl Microbiol 6:323–327, 1958.

128. JF Patterson. Salt tolerant and nitrate reduction by micrococci from fresh pork, curing picklesand bacon. J Appl Bacteriol 26: 80–85, 1963.

129. M Matsura, H Negishi, S Yoshikawa. Effects of sugars on texture of dried meat. NipponShokuhin Kogyo Gakkaishi 37 (5): 363–368, 1990.

130. L Leistner, W Wodel. The stability of intermediate moisture foods with respect to microor-ganisms. In: R Davies, GG Birch, KJ Parker, ed. Intermediate Moisture Food. London: Ap-plied Science, 1976, pp 120–137.

131. DT Bartholomew, TN Blumer. Inhibition of Staphylococcus aureusi by lactic acid bacteria incountry-style hams. J Food Sci 45: 420–425, 430, 1980.

132. M Roca, K Incze. Fermented sausages. Food Rev Int 6: 91–118, 1990.133. J Kopp. Influence of temperature, cooking-time and salt concentration on the solubility of col-

lagen in porcine muscle. Fleschwirt 51: 1647–1651, 1971.134. GJ Lewis. Meat products. In: JG Vaughan, ed. Food Microscopy, London: Academic Press,

1979, pp 233–272.135. DN Rhodes, RCD Jones, BB Curystall, JM Harries. Meat texture II: The relationship between

subjective assessments and a compressive test on roast beef. J Text Stud 3: 298–309, 1972.



136. VL Durance, DL Restall, H Beard, FJ Bourne, AJ Bailey. The location of three collagen typesin skeletal Muscle. FEBS Letters 79: 248, 1977.

137. V Mohr, JR Bendall. Constitution and physical chemical properties of intramuscular connec-tive tissue. Nature 222: 404–405, 1969.

138. DG Siegel, DM Theno, GR Schmidt. Meat massaging: the effect of salt, phosphate and mas-saging on the presence of specific skeletal muscle proteins in the exudate of a sectioned andformed ham. J Food Sci 43: 327–330, 1978.

139. TJ Sims, AJ Bailey. Structural aspects of cooked meat. In: DA Leward, DE Johnston, MKKnight, ed. The Chemistry of Muscle-based Foods. Cambridge: Royal Soc Chem, 1992, pp106–112.

140. M Matsuura, H Negishi, S Yoshikawa. Effect of changes in biochemical properties of my-ofibrillar proteins during heat-drying on texture of dried meat. Nippon Shokuhin KogyoGakkaishi 38 (3): 196–201, 1991.

141. L Leistner. Hurdle technology applied to meat products of the shelf stable product and inter-mediate moisture food types. In: D Sinatos, JL Multon, ed. Properties of Water in Foods: inRelation to Quality and Stability Dardrecht: M. Nijhoff, 1985, pp 309–329.

142. JG Kapsalis. The influence of water on textural parameters in foods at intermediate moisturelevels. In: RB Duckworth, ed. Water Relations of Foods. New York: Academic Press, 1975,pp 627–653.

143. H Riemann. Food Borne Infections and Intoxications. New York: Academic Press. 1969.144. P Baldini, M Campanini, G Pezzani, F Palmia, F. Reduction de la quantite de chlorure de

sodium employe dans less produits seches. Viandes et Produits Carnes 5 (3): 83–88, 1984.145. D Krotje. Starter cultures. New developments in meat products. Int Food Ingredients 6: 14–18,

1992.146. ZA Obanu, DA Ledward, RA Lawrie. Lipid-protein interactions as agents of quality deterio-

ration in intermediate moisture meats: an appraisal. Meat Sci 4: 79–88, 1980.147. TM Okonkwo, ZA Obanu, DA Ledward. Characteristics of some intermediate moisture

smoked meats. Meat Sci 31: 135–145, 1992.148. AA Ibrahim, HT El-Zanfaly, AR Abd-El-Latif. Keeping quality studies on dried meat patties.

Chemie Mikrobiologie Technologie der Lebensmittel 9 (3): 76–80, 1985.149. SM Kim, SK Sung. Effects of level of glycerol addition on physicochemical characteristics of

intermediate moisture meat. Korean J Animal Sci 31 (5): 342–352, 1989.150. K Prabhakar, R Ramamurthi. A study on the preparation of intermediate moisture meat. J Food

Sci Technol (India) 27 (3): 162–164, 1990.151. G Rohns, HD Lechte. Shelf-stable organoleptically acceptable meat product without chemical

preservatives, and process for its manufacture. German Federal Republic Patent ApplicationPI DE 3630131 A1 1988.

152. EAE Boyle, JN Sofos, GR Schmidt, G. R. Depression of aw by soluble and insoluble solids inalginate restructured beef heart meat. J Food Sci 58 (5): 959–962, 967, 1993.

153. K Prabhakar, CV Govindarajan, VR Kosalaraman, AM Shanmugam. Colour and related qual-ity changes in intermediate moisture meats. J Food Sci Technol (India) 29 (1) 65–67, 1992.

154. M Muguruma, K Katayama, M Nakamura, M Yamaguchi. Low-temperature osmotic dehy-dration improves the quality of intermediate moisture meats. Meat Sci 21 (2): 99–109, 1987.

155. S Kalilou, A Collignan, N Zakhia. Optimizing the traditional processing of beef into kilishi.Meat Sci 50: 21–32, 1998.

442 Huang and Nip


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