Journal of the Science of Food and Agriculture J Sci Food Agric 79 :507–516 (1999)

Eating quality of low-fat beef burgers containingfat-replacing functional blendsDeclan J Troy,1* Eoin M Des mond1 and D J Buckley21 Teagas c , The National Food Centre, Duns inea, Cas tleknock, Dublin 15, Ireland

2 Department of Food Science and Technology, Univers ity College, Cork, Ireland

Abstract : Tapioca starch, carrageenan, oat übre, pectin, whey protein and a commercial mixture of

carrageenan and locust bean gum were assessed for their ability to mimic fat characteristics in cooked

low-fat (10%) beef burgers. Thirteen diþ erent blends of the ingredients were formulated in order to

examine their eþ ects on quality parameters of low-fat beef burgers. The beef burgers were tested for

cook yield, water-holding capacity (WHC), retention of shape, sensory and mechanical texture

analysis. Most blends signiücantly (P Æ 0.05) increased both cook yield and WHC, in particular blends

containing tapioca starch, oat übre, whey protein and the carrageenan/locust bean gum mixture.

These blends substantially reduced both Warner–Bratzler and Kramer shear values. Sensory analysis

showed that beef burgers containing tapioca starch, oat übre and whey protein were acceptable in

terms of ýavour and texture. The low-fat control was found to be the toughest and driest of the beef

burgers examined. This study shows that blends of these ingredients can be used to oþ set the poor

quality associated with low-fat beef burgers.

1999 Society of Chemical Industry(

Keywords: low-fat ; beef burgers ; fat replacers ; sensory quality ; non-meat ingredients

INTRODUCTION

Concern about the role diet plays in general healthand development of certain diseases have mounted inthe last number of years. Red meat in the diet, inparticular, has been the focus of interest in modiü-cation of dietary patterns. Reducing the fat level inmeat products is difficult and results in reduction intenderness, juiciness, ýavour intensity and overallproduct palatability.1h5

To maintain desirable palatability in low-fat meatproducts, several non-meat ingredients that act astexture and/or water binding modiüers have beentested with some success. Often these ingredients areexamined alone and rarely have a combination ofthese ingredients in the same formulation beenexamined. This study investigated blends incorpor-ating tapioca starch, oat übre, whey protein, carra-geenan and a carrageenan/locust bean gum mixture.

Hart and Price6 found that a tapiocaTapiocaline},starch, as well as aiding in the retention and sub-sequent release of moisture, giving increased suc-culence, also appeared to aid in ýavour release.

was rated higher than the reduced fatTapiocaline}control recipe and similarly to the standard fatcontrol. Troutt et al3 found that added ingredientssuch as oat übre improved the palatability of 5 and10% fat ground beef. Advantages of using oat bran

as the primary ingredients include its superior abilityto retain moisture and keep meats from drying outwhen cooked, its mouthfeel imitates fat and its abilityto retain the natural ýavourings of the meat.7 El-Magoli et al8 concluded that addition of wheyprotein concentrate (WPC) will increase fat bindingin the meat system, even at lower fat levels (10% fat),and therefore improve both ýavour and texture.WPC improved the cooking characteristics of thelow-fat ground beef patties. Carrageenan with orwithout gum blends is the most widely used binderin the series of current low-fat meat products due toits ability to retain moisture.9 Egbert et al1 foundthat when carrageenan was used at a 0.5% level in an8% fat ground beef formulation, the sensory charac-teristics were similar to those of a 20% fat burger.

Troutt et al3 found that a three-way combinationof dietary übres, starches and reducedPolydextrose}cooking losses, reduced mechanical shear values tobe similar to those for 20% and 30% fat controls.These combinations were also found to producesimilar ýavour in 5% or 10% fat beef patties to thatobtained with 20% fat levels in all beef patties. Thusthe objective of this study was to examine newmethods for improving the palatability of low-fatbeef burgers by addition of blends of fat substituteseach imparting their own quality attribute.

* Corres pondence to : J. Teagas c, The NationalDeclan Troy,

Food Centre, Duns inea, Cas tleknock, Dublin 15, Ireland

E-mail : d.troy=nfc.teagas c.ie

Contract/grant s pons or : Teagas c

Contract/grant s pons or : EU AAIR programme

(Received 8 Augus t 1997 ; revis ed vers ion received 6 January

1998; accepted 2 July 1998)

( 1999 Society of Chemical Industry. J Sci Food Agric 0022–5142/99/$17.50 507

DJ Troy, EM Desmond, DJ Buckley

MATERIALS AND METHODS

Beef burger manufacture

Fifteen diþerent beef burger formulations (Table 1)were prepared in two separate trials. Lean beef(95%VL) forequarter and fat from Hereford crossheifers (18–24 months old) were obtained from TheNational Food Centre’s abattoir and coarsely groundin a Manca PT-82/22 mincer (Manca ButcherEquipment, Barcelona, Spain) through a 10mmplate. The temperature of the meat at grinding wasD4¡C. The meat was randomised both before andafter grinding to minimise inter-animal variability.All meat preparation was performed at 5–10¡C.

The appropriate amounts of lean beef and fattrimmings were used to manufacture batches oflow-fat beef burgers with fat levels of 8%, each con-taining one of the following blends (see Table 1):tapioca starch/oat übre/whey protein ; tapioca starch/pectin/whey protein ; pectin/whey protein,carrageenan ] locust bean gum/oat übre/wheyprotein ; carrageenan ] locust bean gum/pectin/wheyprotein ; carrageenan/oat übre/whey protein ;carrageenan/pectin/whey protein ; tapioca starch/oatübre; tapioca starch/pectin ; carrageenan ] locustbean gum/oat übre; carrageenan ] locust bean gum/pectin ; carrageenan/oat übre; carrageenan/pectin.The levels were chosen on the basis of manufac-turer’s guidelines and previous research10 carriedout.

The meat was mixed in 5kg batches in a MancaMixer (Model RM 90, Manca Butcher Equipment,Barcelona, Spain) with the addition of the blendwhich had been hydrated with water. Appropriateamounts of encapsulated salt (Balchem Corp, POBox 175, Slate Hill, New York 10973, USA) wasthen added. The meat mixture was then ünallyminced through a 5mm plate. Beef burgers (113g)were formed using a Manca burger press. Burgerswere stacked four high and frozen overnight in

plastic lined boxes at [20¡C. Once frozen, burgerswere then vac-packed, four per bag, and returned to[20¡C until required. Two replications of theexperiment were conducted each at separate times.

Proximate analysis

Beef burger samples, both raw and cooked, wereanalysed for percentage moisture, fat and protein.Percentage moisture and fat were determined using aCEM analysis system,11 while percentage proteinwas determined using the Leco 428P NitrogenDeterminator.12 Samples of raw and cooked beefburgers were prepared by blending two beef burgersper replicate using a Robot Coupe Blender (R301Ultra, Robot Coupe SA, France). Two replicates pertreatment were analysed.

Cook yield

Beef burgers were cooked from a frozen state in anelectric grill for 12min and turned every 2min. Theinternal temperature of the beef burgers was mea-sured using a hand-held temperature probe to ensurean internal temperature of 71¡C was reached. Per-centage cooking yield was calculated as the diþeren-tial weight between individual uncooked and cookedbeef burgers for üve replicates per treatment.2

Dimensional shrinkage

Percentage shrinkage was determined as the diþer-ence in average diameter of raw and cooked beefburgers for üve replicates per treatment.2

Water-holding capacity of cooked burgers

Approximately two 10g samples per treatment wereweighed into glass jars and then heated at 90¡C for10min in a water bath. After heating, the sampleswere carefully removed from the jars with the aid of

Table 1. Formulations for controls and treatments with added ingredients (g kgÉ1)

Lean Water Salt Tapioca Oat Whey Pectin Carrageenan] Carrageenan

meat* s tarch fibre protein LB gum

High-fat control 915 80 5 È È È È È ÈLow-fat control 915 80 5 È È È È È ÈTapioca s tarch/fibre/whey protein 885 80 5 15 5 10 È È ÈTapioca s tarch/pectin/whey protein 885 80 5 10 È 10 10 È ÈPectin/whey protein 885 80 5 È È 15 15 È ÈCarrageenan] LB gum/fibre/whey protein 890 80 10 È 5 10 È 5 ÈCarrageenan] LB gum/pectin/whey protein 885 80 10 È È 10 10 5 ÈCarrageenan/oat fibre/whey protein 890 80 10 È 5 10 È È 5

Carrageenan/pectin/whey protein 885 80 10 È È 10 5 È 5

Tapioca s tarch/oat fibre 890 80 5 15 10 È È È ÈTapioca s tarch/pectin 890 80 5 15 È È 10 È ÈCarrageenan] LB gum/oat fibre 900 80 10 È 5 È È 5 ÈCarrageenan] LB gum/pectin 900 80 10 È È È 5 5 ÈCarrageenan/oat fibre 900 80 10 È 5 È È È 5

Carrageenan/pectin 900 80 10 È È È 5 È 5

* Meat for high-fat control was D80% VL; meat for low-fat treatments was D90%VL.

508 J Sci Food Agric 79 :507–516 (1999)

Eating quality of low-fat beef burgers

Table 2. Compos ition of raw and cooked beef burgers

Blend Uncooked compos ition Cooked compos ition

%mois ture %fat %protein %mois ture %fat %protein

High-fat control 59.5a 23.0c 17.6ab 51.4a 18.1f 29.3abcd

Low-fat control 70.3def 9.2b 19.1abc 53.0b 14.5e 31.0d

Tapioca s tarch/oat fibre/whey protein 69.3bcd 8.3ab 16.9a 57.1fg 9.9a 27.5a

Tapioca s tarch/pectin/whey protein 70.8f 7.6a 18.7abc 55.4cde 10.9abc 29.4bcd

Pectin/whey protein 70.1def 8.4ab 19.5bc 54.2bc 12.9de 30.6cd

Carrageenan] LB gum/oat fibre/whey protein 69.5bcde 8.6ab 19.7bc 57.4g 10.7abc 28.2ab

Carrageenan] LB gum/pectin/whey protein 70.2def 8.1ab 19.4bc 58.9h 10.1ab 27.5ab

Carrageenan/oat fibre/whey protein 69.6bcde 8.4ab 19.5bc 57.1fg 10.8abc 27.9ab

Carrageenan/pectin/whey protein 69.1bc 9.3b 20.3c 55.9def 11.9cd 28.9abcd

Tapioca s tarch/oat fibre 68.7b 9.1b 19.1abc 55.3cd 11.9bcd 27.4a

Tapioca s tarch/pectin 69.4bcde 9.0b 19.9c 57.9gh 10.8abc 27.2a

Carrageenan] LB gum/oat fibre 69.8def 8.5ab 18.4abc 56.7efg 11.7abc 29.0abcd

Carrageenan] LB gum/pectin 70.4ef 8.6ab 19.1abc 57.9gh 10.1ab 28.3abc

Carrageenan/oat fibre 70.1def 8.5ab 18.2abc 57.4g 11.3abcd 27.9ab

Carrageenan/pectin 70.2def 9.1ab 16.9a 57.5gh 11.2abcd 28.2ab

a–h means in the s ame column with different letters are different (P\ 0.05)

tweezers. When the samples had cooled at room tem-perature, they were wrapped in cotton cheese clothand placed into 50ml polycarbonate centrifuge tubeswith enough absorbent cotton wool on the bottom.The samples were then centrifuged for 10min at9000] g at 4¡C, then the samples were reweighed.The WHC value was then calculated for üve repli-cates per treatment using the following equation:13

%W HC\ 1 [ TM

] 100 \ 1 [ B[ AM

] 100

where WHC is the water-holding capacity, T is thetotal juice loss during heating and centrifuging, B isthe weight of sample before heating, A is the weightof sample after heating and centrifuging and M is thetotal water content in sample.

Sensory analysis

Sensory analysis was performed by a ten member in-house taste panel that evaluated the beef burgers fora number of textural, ýavour and overall qualityattributes as described by Jeþery and Lewis.14 Thepanel was chosen from a pool of 16 selected assessorsbased on their experience in sensory analysis of meatproducts and on their availability. Training consistedof presenting treatments in three preliminary sess-ions to the panellists to familiarise them with thecharacteristics to be evaluated in accordance with theAmerican Meat Science Association (AMSA) guide-lines.15 Tenderness, moistness/juiciness and meatýavour were evaluated by means of eight-pointstructured scales (8\ extremely tender, juice andintense, respectively ; 1\ extremely tough, dry and

bland, respectively). Non-meat ýavour, overallýavour, overall texture and overall acceptability wereevaluated by means of six-point structured scales(6\ extremely intense, very good, very good andextremely acceptable, respectively ; 1\ none, verypoor, very poor and not acceptable, respectively).Beef burgers were cooked as previously describedand cut into quarters. Four samples per session wereserved immediately to panellists in random order.Panellists were instructed to cleanse their palatesbetween samples using water. Each sample wascoded with randomly selected 3-digit numbers. Eachtreatment from each replication was evaluated in twoseparate sessions given a total of 16 sessions.

Mechanical texture analysis

Beef burgers were analysed using the Instron Uni-versal Testing Machine (Model 4464, Instron UKLtd, High Wycombe, Buckinghamshire, UK) usingtwo attachments : Warner–Bratzler V-shaped bladeand the multi-bladed Kramer shearing device,attached to a 500N and 2kN load cell, respectively.For Warner–Bratzler shear, ten burgers per formula-tion were cooked according to procedures previouslydescribed and then cooled to room temperature(B1h) before sampling. Two 2.5cm wide sectionswere removed per burger. Each section was shearedin üve separate locations. The crosshead speed was25cm min~1. Instrumental values obtained from theshear force test included peak force (N) and peakenergy (J).2

For Kramer shear, ten burgers per formulationwere cooked according to procedures previouslydescribed and then cooled to room temperature(B1h) before sampling. Two 2.5cm wide ] 6.0cm

J Sci Food Agric 79 :507–516 (1999) 509

DJ Troy, EM Desmond, DJ Buckley

long strips were removed per burger, weighed andthen sheared. The crosshead speed was 20cm min~1.Instrumental values obtained from the shear forcetest included peak force (kN) and peak energy (J).Peak force and peak energy were divided by theweight of each 2.5] 6.0cm piece to obtain force orenergy per gram.16

Statistical analysis

The trial was performed twice and the data fromboth were combined prior to statistical analysis. Datawere analysed using one-way analysis of variancewith the ingredient blend as the factor. In the case ofsensory analysis, the data was averaged over the 10assessors to minimise the eþect of assessor diþer-ences. When F values were signiücant (P \ 0.05),the mean separation technique of Tukey wasemployed.17 Correlations were carried out using themeans from each treatment and calculated by thePearson correlation model. The software used wasStatGraphics Version 5.0.

RESULTS AND DISCUSSION

Composition

The raw low-fat beef burgers had a moisture contentranging between 68.7–70.8% (Table 2) with a meanvalue of 69.8%, a fat content ranging from 7.6–9.3%with a mean of 8.6%, which was near the desiredlow-fat level of 8%. The full-fat control had lowermoisture and greater fat contents than the low-fattreatments. Other researchers3,4,18,19 have shownsimilar results. In most cases the fat levels betweenthe beef burgers containing the various blends werenot signiücantly (P [ 0.05) diþerent. Signiücant dif-

ferences were found among the protein contents ofthe low-fat treatments that ranged from 16.9–20.3%.This is due to the fact that some treatments hadwhey protein added. This diþerence in protein con-tents would have a signiücant eþect on the texture ofthe beef burgers. Compositional data for cooked beefburgers (Table 2) supported previousresearch,3,4,18h20 in that on cooking, percentagemoisture (w/w) decreased (P \ 0.05) as fat levelincreased. Percentage fat (w/w) increased on cookingfor the low-fat treatments while a concomitantdecrease occurred in the high-fat control. Tornberget al21 in their study concluded that fat was moreeasily removed during cooking from higher-fat beefburgers. This is a result of the product having a lowdensity meat protein matrix, together with a high-fatinstability, giving rise to the higher fat losses. Thelow-fat control had one of the highest proteincontent on cooking due to the large moisture lossduring cooking. In all cases, as a result of cookingthere was a substantial increase in percentageprotein. This is in agreement with previousresearch.1,4,16,22

Physical traits

Physical characteristics of cooked beef burgers areshown in Table 3. Both controls had low cook yieldsin comparison to the other treatments, indicatingthey did not retain much moisture on cooking. Thisconcurs with the compositional analysis. Tornberg etal21 concluded that fat was more easily removedduring cooking from higher-fat beef burgers there-fore lowering the cook yield. Troutt et al4 found thatbeef burgers containing 30% fat had the greatest(P \ 0.05) cooking losses ; beef burgers with 25% fatwere intermediate and 5, 10, 15 and 20% fat levelswere lower and similar (P [ 0.05) to each other.

Table 3. Phys ical traits of pre-cooked low-fat beef burgers

Blend %cook yield %water-holding capacity %reduction in diameter

High-fat control 53.1a 16.39a 25.7d

Low-fat control 58.2b 31.99b 21.5bc

Tapioca s tarch/oat fibre/whey protein 66.9def 42.07h 18.9a

Tapioca s tarch/pectin/whey protein 61.3bc 37.39ef 20.7abc

Pectin/whey protein 59.1b 33.39bc 22.5c

Carrageenan] LB gum/oat fibre/whey protein 65.9def 39.06fg 19.1ab

Carrageenan] LB gum/pectin/whey protein 69.0f 40.20gh 19.1ab

Carrageenan/oat fibre/whey protein 68.3ef 37.65ef 18.2a

Carrageenan/pectin/whey protein 65.1de 64.53cd 19.2ab

Tapioca s tarch/oat fibre 65.6def 40.28gh 18.9a

Tapioca s tarch/pectin 65.3de 36.33de 19.6ab

Carrageenan] LB gum/oat fibre 66.7def 38.95fg 19.9abc

Carrageenan] LB gum/pectin 63.6cd 38.38efg 21.6bc

Carrageenan/oat-fibre 65.9def 38.72fg 18.5a

Carrageenan/pectin 64.6cd 33.01bc 20.6abc

a–f means in the s ame column with different letters are different (P\ 0.05)

510 J Sci Food Agric 79 :507–516 (1999)

Eating quality of low-fat beef burgers

Table 4. Sens ory panel ratings for low-fat beef burgers

Blend Tendernes s Juicines s Meaty Non-meat Overall Overall Overall

flavour flavour flavour texture acceptability

High-fat control 5.9cd 6.1cde 6.2a 1.7ab 4.5bc 4.1abcdef 4.4bcd

Low-fat control 4.7a 4.6a 5.7a 1.5ab 4.1b 3.5a 4.1abc

Tapioca s tarch/oat fibre/whey protein 7.4g 6.6e 6.0a 1.1a 4.5bc 4.5cdef 4.7cd

Tapioca s tarch/pectin/whey protein 6.4cde 6.1cde 6.0a 1.6ab 4.3bc 4.3bcdef 4.5bcd

Pectin/whey protein 5.0ab 5.1ab 5.6a 1.9ab 4.2bc 3.8abc 3.8ab

Carrageenan] LB gum/oat fibre/whey protein 5.9cd 5.6bcd 5.7a 1.6ab 4.2bc 4.4bcdef 4.4bcd

Carrageenan] LB gum/pectin/whey protein 6.2cde 5.8bcde 5.7a 3.0c 3.1a 3.7ab 3.5a

Carrageenan/oat fibre/whey protein 6.5def 6.3de 6.2a 1.6ab 4.6bc 4.7ef 4.8cd

Carrageenan/pectin/whey protein 6.4cde 5.6bcd 5.8a 2.0b 4.0b 4.3bcdef 4.2abcd

Tapioca s tarch/oat fibre 6.9efg 6.1cde 6.3a 1.3ab 4.6bc 4.8f 4.7cd

Tapioca s tarch/pectin 7.2fg 6.5e 6.1a 1.4ab 5.0c 4.7ef 4.8cd

Carrageenan] LB gum/oat fibre 6.7efg 6.2de 6.3a 1.5ab 4.6bc 4.6def 4.9d

Carrageenan] LB gum/pectin 6.2cde 5.3abc 5.6a 1.9ab 4.1b 4.0abcde 4.1abc

Carrageenan/oat fibre 5.9cd 5.3abc 5.5a 2.0b 3.8ab 3.9abcd 3.9ab

Carrageenan/pectin 5.7bc 5.3abc 5.8a 1.8ab 4.1b 4.0abcde 4.2abcd

a–h means in the s ame column with different letters are different (P\ 0.05)Tendernes s , juicines s and meaty flavour were evaluated by means of eight-point s cales (8\ extremely tender/juicy/intens e, res pectively ; 1\ extremelytough/dry/bland, res pectively). Non-meat flavour, overall flavour, overall texture and over all acceptability were evaluated by means of s ix-point s tructureds cales (6\ extremely intens e/very good/very good/extremely acceptable, res pectively ; 1\ none/very poor/not acceptable, res pectively)

In this study, the low-fat meat systems containingblends of carrageenan ] locust bean gum mixture/pectin/whey protein and carrageenan/oat übre/wheyprotein had the highest cook yields of 69.0% and68.3%, respectively, with the majority of burgershaving cook yields of between 61.3–66.9%. All theblends except pectin/whey and tapioca/pectin/wheysigniücantly (P \ 0.05) increased the cook yieldsabove both the full- and low-fat controls, thus indi-cating the blend of non-meat ingredients’ capabilityof binding and retaining moisture during the cookingprocess.

Troutt et al3 found that low-fat patties containingblends of potato starch, sugar beetPolydextrose},übre, oat übre and pea übre also signiücantlyreduced cooking loss (P \ 0.05). Egbert et al1reported that beef burgers containing carrageenanhad signiücantly lower total cooking losses than 20%fat beef burgers. Iota-carrageenan has a synergisticeþect with locust bean gum; this combination pro-vides enhancement of gel strength and a lesser degreeof synersis. Oat bran has the ability to retain mois-ture and keep meats from drying out.23 El-Magoli etal8 reported that beef burgers formulated with waterand whey protein concentrate (0–4%) showed anincrease in yield compared to the controls, as is thecase in this study. Thus, it appears that the observedincreases in yield by whey protein concentrate addi-tion must be related to fat retention. This may be theresult of whey proteins having excellent surfaceactive properties which allow them to re-orient andreduce interfacial tension with increased opportunityfor fat–protein interacting.24

Most of the blends tested resulted in an increase inwater-holding capacity (WHC) of the cookedproduct (Table 3), in a similar fashion to the cook

yield results. All low-fat systems had a signiücantlyhigher (P \ 0.05) WHC values than the full-fatcontrol (16.4%). This low value is probably due tothe fact that the high-fat control, being high in fatand low in protein, was unable to retain the 8%added water. Also, the fact that there was a lowermoisture content and a high fat content (23%), whichis more easily removed during cooking21, may con-tribute to the low WHC value. Demos andMandigo25 also found low-fat (10%) treatments tohave higher (P \ 0.05) WHC values than those madewith 20% fat. Burgers containing blends of tapiocastarch/oat übre/whey protein, tapioca starch/oat übreand the carrageenan ] locust bean gum mixture/pectin/whey protein had the highest WHC values of42.07%, 40.28% and 40.21%, respectively, with themajority of burgers having a WHC value of between36–40%.

Products containing tapioca starch increased theirWHC due to its ability to absorb large amounts ofwater and to retain this moisture during cooking.Hart and Price6 found that tapioca starch aided inretention of moisture in beef burgers. Giese9 reportsthat modiüed food starches can be used as binders tomaintain juiciness and hardness in low-fat meat pro-ducts. The starch is used to structure and bindwater. Bullock et al22 showed that LeanbindTM hadone of the highest WHC values, indicating the meatproduct’s ability to bind moisture in the raw state.Troutt et al3 reported that beef burgers containingsugar übre, pea übre and potato starch consistentlyhad cooking losses 20 to 40% less than those oflow-fat controls without additives, therefore theingredients enhanced water retention.

Most blends containing pectin had the lowestWHC, but similar to the low-fat control, which may

J Sci Food Agric 79 :507–516 (1999) 511

DJ Troy, EM Desmond, DJ Buckley

be due to synersis. The pectin concentration, pH andcalcium content of the solution all have an impactupon the strength of the low-methoxyl pectin gels.With pectin at high calcium levels, the gels formedare brittle and prone to synersis.24 The WHC seemsto improve due to the addition of other ingredients inthe blend such as carrageenan. Its greatest advantageis its ability to retain moisture.26 Oat bran/übre actsin a similar fashion.9

All treatments had a reduction in diameter (Table3) with the full-fat control shrinking the most, due tothe high loss in fat and moisture during cooking.Treatments containing oat übre, tapioca starch andwhey protein had the least shrinkage. However, allthe diþerences in reduction of patty diameter duringcooking were relatively minor. One of the treatmentscontaining pectin had the highest shrinkage whichconcurs with the low WHC results and thus thediameter would be reduced due to the high loss ofmoisture. Trott et al4 found no eþects of fat level (5,10, 15, 20%) on changes in burger diameter,however, Berry and Wergin27 found that patties with5% fat combined with pregelatinised potato starchreduced patty diameter signiücantly (P \ 0.05).

Sensory analysis

Sensory traits (Table 4), except for meaty ýavour,showed that they were signiücantly aþected(P \ 0.05) by the added blends. Previously, Egbertet al,1 Berry2 and Berry and Wergin27 have shownfat reductions from 20 to 5% in beef burgers haveresulted in a lower incidence of beef ýavour.However, other studies have shown no diþerences inbeef ýavour within these ranges of fatcontent.3,4,18,28

The full-fat control was signiücantly (P \ 0.05)more tender than the low-fat control, which wasfound to be the least tender and the driest of the beefburgers examined. Several studies1h4,16 have foundsimilar results for low-fat controls, the beef burgersbeing lower in juiciness, texture and overall accept-ability. Beef burgers containing the blend of tapiocastarch/oat übre/whey protein were found to be themost tender and signiücantly (P \ 0.05) more tenderthan the full-fat control, which could be attributed tothe increased WHC of the product during cooking.Hart and Price6 reported that tapioca starch gave thedesired tenderness for low-fat beef burgers. Giese9reported that oat products provide textural enhance-ment to low-fat meat products. Troutt et al3 showedthat in 5 and 10% fat beef burgers the use of potatostarch in combination with various plant übre ingre-dients produced slightly less ürmness and lesscohesiveness of the chewed mass. Taki29 reportedthat the incorporation of a ‘functional blend’ con-taining modiüed food starch, rice ýour, salt, emulsi-üer and ýavour improved the tenderness of low-fatbeef burgers and were better than other beef burgersformulated with other ingredients.

All of the low-fat treatments, with the exception of

pectin/whey protein blend, had a similar level ofjuiciness to the full-fat control, indicating that theblends retained the appropriate amount of moistureto assure a succulent product. As with the tendernessattribute, the low-fat control was rated the lowest forjuiciness (P \ 0.05). Previously, Kregrel et al18Egbert et al1 and Berry2 showed that beef burgers of10% or lower fat contents were rated lower in juici-ness. Beef burgers containing blends with tapiocastarch, oat übre, whey protein and carrageenans wereranked the highest. Tapioca starch gave a more juicyproduct aiding in moisture release, giving increasedsucculence. These results concur with both the cookyield and WHC results. However, Troutt et al3reported that beef burgers formulated with potatostarch that was blended with various plant übres hadlower juiciness scores compared to the full-fat con-trols. Taki29 found that the use of a functional blendgave a more juicy product. Beef burger formulationscontaining carrageenan were also found to improvejuiciness signiücantly.1,22 An explanation for thismight be that iota-carrageenan is a gelling agent thatforms thermoreversible gels. In the presence ofcalcium ions the gel formed is clear, elastic andsyneresis-free and resets after shear.24 It is the mosteþective carrageenan to use for moisture retention inlow-fat beef burgers.1

Most of the blends imparted no serious non-meatýavour in the beef burger formulations. The blendwith carrageenan ] locust bean gum mixture/pectin/whey had the highest non-meat ýavour, but was onlyslightly intense. However, it was signiücantly moreintense (P \ 0.05) than beef burgers containingblends of tapioca starch/übre/whey protein,carrageenan/übre/whey protein and also the low-fatcontrol. Bullock et al22 found no diþerences(P [ 0.05) in oþ-ýavour when various carrageenans,gum blends and starches were incorporated intolow-fat beef burger formulations. The addition ofmodiüed pregelatinised potato starch (MPPS)reduced beef ýavour scores and gave occasional acidýavours in MPPS-added beef burgers.27

Overall the blends had a signiücant diþerence(P \ 0.05) on the overall ýavour attribute. However,most blends were rated similarly, including both thelow- and full-fat controls. Huþman and Egbert26found no diþerences in beef ýavour intensities over arange of 5 to 20% fat content beef burgers. Similarly,Berry and Leddy30 found no diþerence in ýavour ofcooked beef burgers over a range of 14 to 24% fatand Kregrel et al18 reported similar ýavour ratings inbeef burgers having 9.5, 21.1 and 28.5% fat. Thesestudies concur with this research, as the low-fatcontrol had 8% fat and the full-fat control had 23%fat content. More recently, Bullock et al22 foundvery little diþerences in ýavour intensity amonglow-fat treatments containing various carbohydrateadditives. El-Magoli et al8 found no signiücant dif-ferences (P [ 0.05) among low-fat treatments withadded whey protein at various levels (1–4%) and the

512 J Sci Food Agric 79 :507–516 (1999)

Eating quality of low-fat beef burgers

low-fat control. As with the non-meat ýavour attrib-ute, the blend containing carrageenan ] locust beangum mixture/pectin/whey protein was rated thelowest, and was signiücantly poorer (P \ 0.05) thanthe blends, carrageenan/übre/whey protein, tapiocastarch/übre, tapioca starch/pectin andcarrageenan ] locust bean gum mixture/übre. Fromthese results the panellists could be picking up somedetrimental ýavours from the pectin or the locustbean gum that are masked in the other blends.

The overall texture results, as with the tendernessand juiciness attributes, gave the low-fat control asranked the lowest but was not signiücantly diþerent(P [ 0.05) to all the treatments including the high-fat control. Most of the low-fat treatments were ratedsimilarly (P [ 0.05). The protein content (Table 2)of the samples which varied would have a strongeþect on texture and juiciness of the product. Theeþect of protein on texture has been attributed toincreased protein–protein interactions and excessivebinding in higher protein products.31 Claus et al32stated that, regardless of whether fat or added wateris constant, changes in texture are dependent on theprotein content, that is, protein content has a moresigniücant role than fat even when the diþerences inprotein are small.

The beef burgers formulated with blends contain-ing tapioca starch, oat übre and pectin were rankedthe highest, indicating that the blend of ingredientswas successful in maintaining the overall texture ofthe low-fat product. Pectin provides a creamy-liketexture mimicking the mouthfeel of fat.33 El-Magoliet al8 found that the incorporation of whey protein inlow-fat beef burgers did not demonstrate improve-ment in texture and that these low-fat treatmentswere signiücantly diþerent from the low-fat control.

Brewer et al28 found that low-fat beef burgers for-mulated with a mixture of carrageenan, starch andphosphate had a rubbery texture and were similar tothe full-fat control.

The overall acceptability results indicate that mostblends were acceptable and similar (P [ 0.05) to thefull-fat control. The only signiücant diþerence beingbetween beef burgers containing blends ofcarrageenan ] locust bean gum mixture/übre andcarrageenan ] locust bean gum mixture/pectin/wheyprotein. Both the low- and high-fat controls weresimilar (P [ 0.05) in terms of acceptability. Huþmanand Egbert26 found that overall acceptability, basedon consumer panel tests, of ground beef productspeaked at a fat content of approximately 20%,however, these authors also found that there were nosigniücant diþerences between patties with a fatcontent of 10 and 20%. However, Barbut andMittal34 found that there was no problem inreducing the fat level by 10% points in the raw or6% points in cooked breakfast sausages. It appearedthat 11% fat in the cooked product resulted in anacceptable product. Bullock et al22 reported that beefburgers containing a variety of carrageenans andgums were found to be acceptable to panellists.Pszczola23 reported that consumers rated low-fatbeef burgers containing oat bran equal to the controland thus acceptable as an alternative to full-fat pro-ducts. Most of the blends added to the low-fat beefburgers in this study were consistent in their qualityand thus the panellists found the low-fat beefburgers acceptable.

Mechanical texture analysis

Warner–Bratzler and Kramer shear values (Table 5)showed that the incorporation of some blends sub-

Table 5. Ins trumental s hear values for cooked low-fat beef burgers

Blend Warner–Bratzler s hear Kramer s hear

Peak force (N) Peak energy (J) Peak force (N gÉ1) Peak energy (J gÉ1)

High-fat control 19.2bc 0.21def 40.0d 0.24a

Low-fat control 25.4gh 0.25hi 54.7i 0.32h

Tapioca s tarch/oat fibre/whey protein 13.8a 0.14a 31.3a 0.17a

Tapioca s tarch/pectin/whey protein 17.9b 0.17bc 35.4bc 0.22cd

Pectin/whey protein 24.1fg 0.23fgh 50.1h 0.32h

Carrageenan]LB gum/oat fibre/whey protein 23.8fg 0.24gh 45.6g 0.31h

Carrageenan]LB gum/pectin/whey protein 19.0bc 0.21de 34.7b 0.24e

Carrageenan/oat fibre/whey protein 23.6efg 0.23gh 45.5g 0.29g

Carrageenan/pectin/whey protein 23.1ef 0.25hi 43.0ef 0.26f

Tapioca s tarch/oat fibre 15.3a 0.25ab 34.8b 0.21c

Tapioca s tarch/pectin 17.6b 0.17bc 32.2a 0.19b

Carrageenan] LB gum/oat fibre 27.2h 0.27gh 37.3c 0.23de

Carrageenan] LB gum/pectin 20.1cd 0.19efg 42.1de 0.28fg

Carrageenan/oat fibre 24.7fg 0.24gh 45.1fg 0.28g

Carrageenan/pectin 21.5de 0.22efg 45.2fg 0.28g

a–h means in the s ame column with different letters are different

J Sci Food Agric 79 :507–516 (1999) 513

DJ Troy, EM Desmond, DJ Buckley

stantially (P \ 0.05) reduced peak force and energyvalues compared to the low-fat control, thus showingincreased tenderness for these products. The low-fatcontrol had one of the highest (P \ 0.05) Warner–Bratzler shear forces and the highest (P \ 0.05)Kramer peak forces, and was signiücantly (P \ 0.05)higher than the full-fat control. This concurs withprevious research.1h4 They reported higher peakload value for beef burgers with 4–8% fat comparedto beef burgers formulated with 20% fat. Theseresults show that fat content has an inverse relation-ship to shear force, fat being less resistant to shearcompared to a hard proteinateous matrix such as thelow-fat control.

Beef burgers formulated with the blends tapiocastarch/oat übre/whey protein, tapioca starch/pectinor oat übre and tapioca starch/pectin/whey proteinsubstantially reduced peak forces and in some casessigniücantly less (P \ 0.05) than the full-fat control.These ingredients, in particular tapioca starch, whenformulated together bind and retain water to producea more tender product, therefore reducing shearforce. Bullock et al22 found that beef burgers formu-lated with Leanbind and algin had lower shear values(P \ 0.05) than other low-fat treatments. Berry andAbraham35 found the use of oat bran and übre, asimulated fat matrix and individually quick frozenbeef burgers with perforations lowered peak load andenergy.

Other non-meat ingredients, in particular carbo-hydrates, when incorporated into low-fat meat for-mulations have shown a reduction (P \ 0.05) inWarner–Bratzler and Kramer shear values, similar tothose of the full-fat control.1,3,36,37 Berry et al5showed that the use of iota-carrageenan substantiallylowered (P \ 0.05) peak load and pre- and post-peakenergy values in contrast to patties containing nocarrageenan. Blackmer37 also found that the additionof carrageenan to low-fat beef burgers formulationsreduced shear force and concluded that this wasprobably a result of both the addition of water (9%)and the ability of the carrageenan to hold the waterby gelling. Troutt et al3 found that three-way ingre-dient blends of and potato starch inPoldextrose}combination with sugar, oat or pea übre reduced(P \ 0.05) both Warner–Bratzler and Kramer shear

values to be similar to those for 20 and 30% fat con-trols.

In this study, the reductions in both Warner–Bratzler and Kramer shear values associated with theincorporation of various blends closely compare totenderness improvements detected by sensory panel-lists. Correlation’s between Instron measures oftexture and sensory panel texture (Table 6) werehigher for Kramer shear values than Warner–Bratzler shear values. Similar results were found byTroutt et al.3,4 The Kramer shear press is a morepopular attachment for the analysis of meat productswhereas the Warner–Bratzler is used for whole meatpieces such as steak. Voisey38 concludes that perhapsthe peak force correlates well with sensory scoresbecause it provides an index of the forces required todisrupt the foods in combination with adhesive andcohesive eþects, ie the Kramer shear cell uses a com-bination of both shearing and compression forces.The Instron scores were consistent with the sensoryscores of tenderness, indicating that the blends werecapable of retaining moisture on cooking, as shownwith the WHC results, giving a more succulentproduct. Tenderness and juiciness correlated wellwith overall acceptability, while overall texture cor-related well (P \ 0.05) with Kramer shear force.This supports earlier statements that the Kramershear attachment is a more useful method of measur-ing mechanical texture of this type of meat product.

CONCLUSIONS

This study indicates that there are a number of fatsubstitutes when blended together have the ability toimprove the palatability of low-fat ground beefproducts. Beef burgers formulated with blendscontaining carrageenan ] locust bean gum mixture/pectin/whey protein, carrageenan/übre/whey proteinand tapioca starch/pectin/whey protein improved thecooking characteristics such as cook yield and WHCof the low-fat beef burgers.

Blends containing tapioca starch, oat übre andwhey protein improved tenderness and in particularlowered shear force, due to the ability of these ingre-dients to retain water and hold it during cooking.

Tender Ms t juc O text O accept Warner

Ms t juc 0.895***O text 0.816*** 0.813*O accept 0.645*** 0.708*** 0.880***Warner [ 0.605* [ 0.565* [ 0.332 [ 0.215Kramer [ 0.887*** [ 0.842*** [ 0.578* [ 0.416 0.744***

Tender : tendernes s ; Ms t/juc : mois tnes s /juicines s ; O text : overall texture ; O accept : overallacceptability ; Warner : Warner–Bratzler s hear force; Kramer: Kramer s hear force; *, P\ 0.05 ;**, P\ 0.01 ; ***, P\ 0.001 ; No s upers cript : non-s ignificant

Table 6. Correlation

coefficients between s ens ory

and Ins tron meas urements

514 J Sci Food Agric 79 :507–516 (1999)

Eating quality of low-fat beef burgers

Overall ýavour and texture were found to be themost important attribute in deciding acceptability,both attributes having high correlations with theoverall acceptability attribute. No signiücant diþer-ence (P [ 0.05) was found for the meaty ýavourattribute indicating that blends were acceptable interms of ýavour. No blend had any detrimental non-meat ýavour. Some of the blends examined weresuperior to the controls in some aspects of theirquality attributes and were similar in other areas.Therefore combinations of texture-modifying ingre-dients such as tapioca starch, oat übre and wheyprotein may have the potential of improving theoverall palatability of low-fat beef burgers, but moreresearch is needed on the optimisation of the com-position of blends.

ACKNOWLEDGEMENTS

The authors wish to thank Teagasc (Agricultural andFood Development Authority) and the EU AAIRprogramme for the funding of this research and thecompanies who supplied the ingredients as well astheir technical assistance. Reference to any brand ortrade name does not constitute endorsement by TheNational Food Centre or The European Union.

REFERENCES1 Egbert WR, Huþman DL, Chen CM and Dylewski DP,

Development of low-fat ground beef. Food Technology 45:64(1991).

2 Berry BW, Low-fat eþects on sensory, shear, cooking andchemical properties of ground beef patties. J Food Sci

57:537 (1992).3 Troutt ES, Hunt MC, Johnson DE, Claus JR, Kastner CL

and Kropf DH, Characteristics of low-fat ground beef con-taining texture modifying ingredients. J Food Sci 57:19(1992).

4 Troutt ES, Hunt MC, Johnson DE, Claus JR, Kastner CL,Kropf DH and Stroda S, Chemical, physical and sensorycharacterisation of ground beef containing 5 to 30% fat. J

Food Sci 57:25 (1992).5 Berry BW, Joseph RL and Stanüeld MS, Use of electrical

stimulation, hot processing and carrageenan for processinglow-fat ground beef. Meat Science 42:111 (1996).

6 Hart B and Price K, New potential for low-fat beef burgers.Food Manufacture, 2:42 (1993).

7 Meinhold NM, Processed meats with 38–75% less fat. Food

Processing 52:105 (1991).8 El-Magoli SB, Laroia S and Hansen PMT, Flavour and

texture characteristics of low-fat ground beef formulatedwith whey protein concentrate. Meat Science 42:179 (1996).

9 Giese J, Developing low-fat meat products. Food Technology

46:100 (1992).10 Desmond EM, Troy DJ and Buckley DJ, Comparative studies

on non-meat ingredients used in the manufacture of low-fatbeef burgers. J Muscle Foods 9 :221 (1998).

11 Bostian ML, Fish DL and Webb NB, Automated methods fordetermination of fat and moisture in meat and poultry pro-ducts : Collaborative study. J Assoc of Official Analytical

Chemists 5:876 (1985).12 Sweeny RA and Rexford PR, Comparison of LECO FP-228

‘Nitrogen Determinator’ with AOAC copper catalyst Hjel-dahl method for crude protein. J Assoc of Oþ Anal Chem

70:1028 (1987).

13 Liangi M and Chen N, Research in improving the WHC ofmeat in sausage products. Proceedings of the 37th Interna-tional Congress of Meat Science and Technology, Copenha-gen, Denmark, p 781 (1991).

14 Jeþery AB and Lewis DF, Studies on beef burgers. Part II :Eþect of mincing plate size and temperature of the meat inthe production of beef burgers. Leatherhead Food RAReport No 439 pp 7–12 (1983).

15 AMSA, Guidelines for sensory, physical, and chemical mea-surements in ground beef. Reciprocal Meats Conference Pro-

ceedings 36:221–228 (1983).16 Miller MF, Anderson MK, Ramsey CB and Reagan JO,

Physical and sensory characteristics of low-fat ground beefpatties. J Food Sci 58:461 (1993).

17 Steel RGD and Torrie JH, Analysis of variance I : Theone-way classiücation, in Principles and Procedures of Sta-

tistics : A Biometrical Approach, McGraw-Hill, New York,pp 137–171 (1980).

18 Kregel KK, Prusa KJ and Hughes KV, Cholesterol contentand sensory analysis of ground beef as inýuenced by fatlevel, heating and storage. J Food Sci 51:1162 (1986).

19 Berry BW, Fat level, high temperature cooking and degree ofdoneness aþect sensory, chemical and physical properties ofbeef patties. J Food Sci 59:10 (1994).

20 Hoelscher LM, Savel JW, Harris JM, Cross HR and RheeKS, Eþect of initial fat level and cooking method on choles-terol content and caloric value of ground beef patties. J Food

Sci 52:883 (1987).21 Tornberg E, Olsson A and Persson K, A comparison in fat

holding between hamburgers and emulsion sausages. Pro-ceedings of the 35th International Congress of Meat Scienceand Technology, Copenhagen, Denmark, III, pp 752–759(1989).

22 Bullock KB, Huþman DL, Egbert WR, Bradford DD, MikelWB and Jones WR, Non-meat ingredients for low-fatground beef patties. J Muscle Foods 6:37 (1995).

23 Pszczola DE, Oat-bran based ingredient blend replaces fat inground beef and pork sausage. Food Technology 45:60(1991).

24 Lucca PA and Tepper BJ, Fat replacers and the functionalityof fat in foods. Trends in Food Sci and Technol 5:12 (1994).

25 Demos BP and Mandigo RW, Physical and chemical andorganoleptic properties of ground beef patties manufacturedwith mechanically recovered neck bone lean. J Muscle Foods

7:175 (1996).26 Huþman DL and Egbert WR, Advances in lean ground beef

production. Alabama Agric Exp Sta Bull No 606. AuburnUniversity, Alabama (1990).

27 Berry BW and Wergin WP, Modiüed pregelatinised potatostarch in low-fat ground beef patties. J Muscle Foods 4:305(1993).

28 Brewer MS, McKeith FK and Britt K, Fat, soy and carragee-nan eþects on sensory and physical characteristics of groundbeef patties. J Food Sci 57:1051 (1992).

29 Taki GH, Functional ingredient blend produces low-fat meatproducts to meet consumers expectations. Food Technology

45:70 (1991).30 Berry BW and Leddy KF, Eþects of fat level and cooking

method on sensory and textural properties of ground beefpatties. J Food Sci 49:870 (1984).

31 Monaghan FJ and Troy DJ, Overcoming sensory problems inlow-fat and low-salt products, in Production and Processing of

Healthy Meat, Poultry and Fish Products. Advances in Meat

Research, Vol. 11, Ed by Pearson AM and Dutson TR,Blackie Academic & Professional, London, pp 257–281(1997).

32 Claus JR, Hunt MC and Kastner CL, Eþects of substitutingadded water for fat on the textural, sensory and processingcharacteristics of bologna. J Muscle Foods 1:1–21 (1989).

33 Anon, Pectin’s functionality ünds use in fat replacer market.Food Technology 45:116 (1991).

34 Barbut S and Mittal GS, Use of carrageenan and xanthan gum

J Sci Food Agric 79 :507–516 (1999) 515

DJ Troy, EM Desmond, DJ Buckley

in reduced fat breakfast sausages. Lebensm.-Wiss. u. Technol.25:509 (1992).

35 Berry BW and Abraham HC, Instrumental measures of ten-derness in low-fat ground beef patties. Proceedings of the39th International Congress of Meat Science and Tech-nology, S7PO3.WP (1993).

36 Kasaback CM, Developments in lean ground beef technology.

MSc thesis, Auburn University, Auburn, Alabama, USA(1991).

37 Blackmer DS, Characterisation of low-fat ground beef pattiesmade with non-meat ingredients. M.Sc. Thesis, Universityof Nebraska, Lincoln, Nebraska, USA (1992).

38 Voisey PW, Interpretation of force deformation curves fromthe shear compression cell. J. Texture Studies 8:19 (1977).

516 J Sci Food Agric 79 :507–516 (1999)