Industrial Lecture 7

8/4/2019 Industrial Lecture 7

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BIO 425Industrial MicrobiologySeyhun YURDUGL

Lecture 7Meat microbiology


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C

ontent outline Fermentation of meat and microflora,

Sausages Soudjouk

Pastrami

Salami(Ham)


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Main products

Fermented sausages

Ham

Soudjouk and pastrami


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Fermentation of meat and microflora Lactic acid bacteria offer microbiological

stability,

and organoleptic properties to meatproducts,

mainly for sausages.


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Sausages These products are made from comminuted

meat & fat,

mixed with salt,

curing agents,

sugar and spices,

and filled into casings.


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Fermented sausage production

Meat is chilled or partially frozen,

comminuted in a meat grinder or cuttermix curing salt, carbohydrates and seasonings,

fatty tissue is comminuted in the frozen

state and added to the mixture.

Subsequent filling into casings occur-under vacuumto eliminate the interference of oxygen with

the formation of desired color and flavor.


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Microflora of sausages:

Largely consists of G (-),

oxidase-positive rods, particularly psychotrophicPseudomonads,

psychotrophicEnterobacteriaceae.


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Lactic acid bacteria in sausages

TASK: To eliminate undesired or hazardous

acid sensitive bacteria, These products are made up with starters-

lactic acid bacteria,

as theyre present in very few amounts; in raw materials.


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Types of lactic acid bacteria

Heterofermentative lactobacilli:

degrade pentose to equimolar quantities of

lactic and acetic acids. Minor fermentation products formed from

carbohydrates by lactic acid bacteria andcatalase positive cocci:

including acetoin, diacetyl and / or 2,3butanediol.

contribute to the cheesy component of the

sausage aroma.


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Main species of lactic acid bacteria

Lactobacillus plantarum

Lactobacillus sake Lactobacillus curvatus

inhibit pathogenic and spoilage bacteria. accelerate color formation and drying.


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C

atalase (+) cocci in sausages Staphylococcus carnosus

Staphylococcus xylosus

involved in nitrite & nitrate reduction.

color formation & stabilization.


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Yeast Debaryomyces hansenii

Candida farnata

removal of excess nitrite,

delay of rancidity, aroma development.


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Molds of sausages Penicillum nalgionensebiotypes 2, 3, 6.

Penicillum chrysogenum.

Function:

Suppression of undesired molds.

Delay of rancidity.


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Soudjouk

Turkish fermented food, made up of 100 %beef

Main species present:

Lactobacillus alimentarius (Grakan et al.,1995)

Lactobacillus plantarum, Lactobacillus

fermentii, Pediococcus cerevisiae.

Ideal soudjouk contains 10-20% fat.


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Soudjouk production

Slaughtering of animal

Deboning of animal carcasses

Processing of meat

Preparation of the soudjouk dough

Filling of the casings(Bumbar)with soudjouk dough

Ripening

Packaging


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Pastrami Originates from bastirma (Turkish word),

stands for Dried meat.

M/os:

Staphylococcus

Micrococcus Lactic acid bacteria.


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Pastrami productionSlaughtering of animal

Deboning of animal carcasses

Processing of meat

Fenugreek addition

Packaging


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Fenugreek Obtained from Trigonella foenum graecum.

Its seed was processed into flour & garlic &red pepper as paste.

and mixed with meat.


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Another category of fermented

meats: Ham(Salami)

Raw unground products such as raw hams,

owe most of their characteristic sensoryproperties to the action of salt,

curing agents,

and proteolytic muscle enzymes.


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Ham production (Salami production)

Selection of meat cuts

Grinding

Mixing with salt & other ingredients.

Sacking

Maturation & seasoning (Duration variesaccording the dimensions and characteristics

of the type of salami)


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Dominant microflora includes:

Enterobacteriaceae spp.

Pseudomonas spp.

Micrococcus spp.

Staphylococcus spp.

Salmonella spp.

Listeria spp.


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Dominant microflora includes: Lactic acid bacteria,

Enterococcus spp.

Total coliforms,

Fecal coliforms,

E.coli, Bacillus spp.


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Dominant microflora includes Salmonella

Listeria

Yersinia

Yeasts

Molds Staphylococcus aureus

Bacillus cereus


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Important criteria in ham production If slaughtering is carried out under stress

conditions for animal,

glucose and other forms of sugar will beeasily consumed;

and inadequate amounts of lactic acid will

be produced; so called rigor mortis happens.


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LITERATUREC

ITED Forsythe, S.J. The Microbiology of Safe

Food, Blackwell Science, Cambridge, 2000.

Wood, B. J. B., Microbiology of FermentedFoods, Vol.1 and 2, Blackie Academic andProfessional, London, Second edition, 1998.

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Industrial Lecture 7