Innovative wholesale carcass fabrication and retail cutting to optimize beef value

Innovations in beef carcass fabrication to improve subprimal yield, retail cut yield, and overall carcass value were evaluated. Alternating sides from 30 beef carcasses were assigned to either an innovative or conventional style of fabrication. The innovative method resulted in greater (P < 0.001) total subprimal yield and less (P < 0.001) lean trimmings from the forequarter; however, hindquarter total subprimal yield and lean trimmings were not affected (P > 0.05) by fabrication style. Value was greater for the innovative forequarter (P < 0.001) and hindquarter (P < 0.01), and total value was increased by more than US $14 per beef carcass compared to the conventional style. Selected subprimals were evaluated in retail cutting tests. In general, the innovative retail subprimals had yields equal to or greater than the conventional subprimals. Innovative carcass fabrication may allow for greater marketing options for beef cuts to improve carcass value and to offer greater retail merchandizing opportunities.     

Secondary sexual development (Masculinity) of bovine males: 1. Influence on carcass composition, cutability, economic value and certain muscles

Differences in carcass composition, cutability, economic value of the carcass and distribution of certain muscle groups, between bulls with secondary sexual characteristics (bulls(+)), those without (bulls(−)), and steers were investigated. Two carcass mass groups (250–300 and 301–350 kg) were compared. Five carcasses of either mass group were studied within each sex condition group. Bulls(+) had a higher meat percentage (P < 0·05) than bulls(−) or steers. They also had a lower bone percentage than steers (P < 0·05), but non-significant differences were found between bulls(+) and bulls(−) for bone percentage. Significant differences (P < 0·05) between sex condition groups were found for percentages of hindquarter, as well as for distribution of high-priced cuts. Steers had the most favourable distribution and bulls(+) the least favourable. Bulls(−) were intermediate.

Masculinity significantly (P < 0·05) influenced the distribution of the chuck, neck, brisket and hind shin cuts, whilst mass had a significant effect on the percentage hind shin and percentage thin flank. It was found that the M. rhomboideus was the only muscle of those studied that was significantly affected by masculinity and it was concluded that this muscle could be used as an indicator of the masculinity of the carcass.

The economic values of the carcasses of steers, bulls without secondary sexual development and bulls with secondary sexual development differed non-significantly.     

An investigation of ultimate pH in the muscles of commercial beef carcasses

Ultimate pH values were recorded in the carcasses of steers and heifers at a beef slaughtering plant over a period of 3 years. The incidence of carcasses with a pH_u ≥ 6·0 in the LD—a value usually associated with ‘dark-cutting’ in beef—was 3·2%. A pronounced seasonal effect was observed with the incidence rising from 1·2% for the period February to August to 5·2% for the period September to January, inclusive. An examination of thirteen muscles showed that increases in pH_u above normal values occurred most frequently in the LD and four large muscles of the hindquarter and were much less frequently observed in the eight other hind- and forequarter muscles examined. In the carcasses of young bulls, also slaughtered under commercial conditions, high pH_u values were predominantly associated with the same muscles as in steers and heifers. However, when experimental cattle were given adrenaline to induced high pH_u values, this treatment resulted in a general increase in pH_u in all the muscles examined. The different pattern of pH_u elevation in the adrenaline-treated and commercial carcasses suggests different physiological mechanisms in the two cases.     

Estimation of mutton carcass components using two predictors

Carcass weight and the GR measurement (a measure of fatness) were used as predictors in models for estimating mutton carcass components. These parameters explained a moderate to large amount of the variation in component weights (r² = 0·47−0·93) except for trunk meat (of a 50% visual lean specification) with an r² = 0·15.

The 557 carcasses used ranged in weight from 9·2 to 43·8 kg and in fat depth at the GR site from 0 to 41·0 mm.

Analysis of the trunk meat components designated 50%, 80% and 90% visual lean showed that despite rigorous slicing the observed chemical lean percentage of the two former categories was less than expected.

The application of the models for price setting of carcasses based on derived rather than nominal values is discussed.     

Effect of pre- and post-pubertal castration on Piemontese male cattle. II: Carcass measures and meat yield

The effect of different castration ages on carcass morphological characteristics, meat yield, commercial cuts and bones weight and measures was evaluated on Piemontese steers and bulls. Carcasses (24) obtained from early castrated (EC, 5th month of age), late castrated (LC, 13th month) and intact males (IM, control group) of similar age (about 18 months) and fattening degree, were weighed, measured and dissected following the local commercial method. Very few differences were found in carcass conformation and fatness as in carcass weight and measures. After data adjusting, few meat cuts were heavier in IM compared to EC and LC, and only one cut measure was different, whereas, almost no differences were found in bone measures and weight. IM produced carcasses with more edible meat than LC and more forequarter and 2nd quality meat than LC and EC. Significant differences were found also between total, hindquarter and perinephric fat.     

Hot water decontamination of beef carcasses for reduction of initial bacterial numbers

Areas on freshly slaughtered beef carcasses were sprayed with hot (95°C), sterilized, distilled water in order to elevate carcass surface temperature to 82°C. A significant (P < 0·05) reduction in bacterial numbers was observed between control (prespray) and hot water treated carcass surfaces. These results indicate that microbial decontamination of beef carcasses with hot water will be effective if an approprite spraying apparatus is used.     

National estimates of the body composition of British cattle, sheep and pigs with special reference to trends in fatness. A review

National carcass classification records for cattle, sheep and pigs were used as a basis for estimating the body composition of British livestock slaughter populations. The tissue percentages of carcasses in each classification fatness range were estimated from regression equations constructed using data from breed comparison trials and other sources. The lipid and protein contents of the tissues were then estimated using regression equations from body composition studies. The mean carcass composition, and lean and fat production from current populations (1984) were compared with those of ten years ago. There has been an important increase of 20 kg (8%) in carcass weight for beef but no change in carcass composition. The average beef carcass in 1984 was estimated to contain 23% lipid (inclusive of lipid in perinephric and retroperitoneal fat). The weight of sheep carcasses has fallen by 0·6 kg (3 1 2% ) since 1977 without any appreciable change in carcass composition. The average sheep carcass in 1984 was estimated to contain 24% lipid. The lipid content of the average pig carcass was estimated to have fallen significantly from 27% in 1975 to 22% in 1984, with a small increase in carcass weight.     

A modified hot processing strategy for beef: effects on fresh meat quality

A modified hot processing (MHP) strategy for beef carcasses using known chilling technology to maintain quality in the higher priced cuts while retaining lower value cuts for further, immediate hot processing was evaluated. Following high voltage electrical stimulation, paired sides from 36 carcasses were either conventionally processed (CP) or reduced in a manner similar to the French pan traité cut. The sides were help in a pre-chiller for 1 h prior to blast chilling at −20°C for 3 h at an air speed of 2·3 m s⁻¹, followed by chilling at 2°C for the remainder of the 24 h period. Overall, MHP of beef carcass sides had minimal effects on fresh meat quality in the longissimus thoracis et lumborum (LTL) and the semimembranosus (SM) muscles despite removing over 50% of the carcass side weight in the form of lower value cuts. Sarcomere length was significantly shorter (P ≤ 0·05) in the anterior (AL) and posterior (PL) LTL which was attributed to the removal of skeletal restraint and carcass weight. The increase in shear value in the AL, location of MHP sides although statistically significant (P ≤ 0·05) would not likely be percieved by consumers. Hence a non-traditional method of processing carcasses by treating low value and high value primal cuts separately, may be viable.     

Variation among beef breeds in carcass retail value at constant carcass saleable meat content and percentage of higher priced cuts

Data from the single slaughter point trials of the Meat and Livestock Commission's (MLC) beef breed evaluation programme were used to examine the importance of retail value (RV) calculation in breed evaluation trials.

The analysis involved a total of 2010 carcasses comprising four production system groups. Sire breeds included Aberdeen-Angus, British Friesian, Charolais, Devon, Hereford, Galloway, Limousin, Lincoln Red, Luing, Simmental, South Devon, Sussex and Welsh Black.

RV was computed as the sum of the values of trimmed deboned primal joints expressed as pence per kilogram of carcass weight. 1981 prices from MLC's Retail Prices Survey for England and Wales were used.

A model was fitted to the RV data for each of the production system groups with effects for sire breed, year and sire breed × year interaction, and with regression on saleable meat percentage in carcass (SM). The largest difference recorded between sire breeds was 2·1 pence/kg (0·85% of overall mean RV). The pooled within-system residual standard deviation after fitting the model was 1·4 pence/kg. When regression on the percentage of total saleable meat in the higher priced cuts (SMD) was added to the model, the corresponding range and residual standard deviation were reduced to 1·0 and 0·8 pence/kg, respectively. In the circumstances, the calculation of RV would, therefore, make only a minor refinement to the results.     

Feeder cattle frame size, muscle thickness and subsequent beef carcass characteristics

Sixty feeder steers were assigned scores for frame size (small, medium or large) and muscle thickness (No. 1, No. 2 or No. 3), fed for 112 days and slaughtered. Grade data were collected for all 60 carcasses; 12 sides (four from each muscle thickness group) were fabricated into boneless, closely trimmed retail cuts and the 12 rounds from each of these sides were also physically separated into muscle, fat and bone. Marbling score and USDA quality grade varied inversely (P < 0·05) with frame size. Carcass quality grades were: 33·3% Choice; 67·7% Good and 0·0% Standard for small-framed cattle; 30·3% Choice, 42·4% Good and 27·3% Standard for medium-framed cattle and 5·5% Choice, 66·7% Good and 27·8% Standard for large-framed cattle. Analysis of variance showed significant (P < 0·05) differences among all muscle thickness groups in the longissimus muscle area and carcass weight but no difference in yield grade between the No. 1 and No. 3 muscle thickness groups; the larger mean longissimus muscle area of carcasses from steers in the No. 1 muscle thickness group was offset by their heavier carcass weight and their greater thickness of fat over the longissimus muscle. However, when analysis of covariance was used to hold fatness or fatness and frame size constant, the difference in yield grade between muscle thickness groups No. 1 and No. 3 was significant (P < 0·05). Also, carcasses from cattle assigned muscle thickness scores of No. 1, as feeders, had the highest (P < 0·05) muscle to bone ratio of the round (4·1 to 1) while carcasses from cattle assigned thickness scores of No. 3, as feeders, had the lowest (P < 0·05) muscle to bone ratio of the round (3·4 to 1).     

A modified hot processing strategy for beef: reduced electrical energy consumption in carcass chilling

A beef processing strategy for improving energy and labour efficiencies, modified hot processing (MHP), was developed in a research abattoir. The work reported herein investigated carcass chilling rates and electrical energy usage in the chilling of carcasses that were processed using this approach. The MHP procedure removes the lower value cuts from the dressed carcass along with associated bone and fat. The remaining high value meat (posterior carcass quarter) is chilled in the usual manner, while the low value cuts are immediately processed (e.g. reduced into pre-blended, salted, chilled meat for emulsion-type products; rendered; directly processed as fresh, hot-boned meat, etc.). Carcasses prepared by the MHP method were dissected to quantify the amounts of lean meat, separable fat and bone removed in the procedure. These data were used with a simple model to predict the amount of chilling energy that could be saved by applying MHP prior to chilling. Electrical power to operate a blast chilling facility containing carcasses that had been processed either by conventional processing or by MHP methods was monitored and recorded, and the resulting data was used to confirm the model result. The MHP procedure reduced the refrigeration load for beef chilling by as much as 51% (P < 0·05). The amount of chilling energy to be saved would depend upon the methods employed to further process the low value tissues, and was calculated to be no less than 7%. The time for the reduced MHP carcass quarters to chill to 10°C at the fat-muscle interface of the longissimus dorsi muscle (12/13 rib) was shorter for MHP carcasses than for conventional carcasses (5·77 h vs 7·08 h, respectively) (P < 0·05). However, the times to chill the deep hip location of MHP hind quarters and conventional beef sides were not significantly different (P < 0·05).     

Isolation and molecular characterization of Escherichia coli O157 isolated from cattle,pigs and chickens at slaughter

From 1999 until 2001, 3625 food samples were examined for the presence of Escherichia coli O157. Samples were from bovine origin (ground beef, n=549; carcasses, n=2452), calves (carcasses, n=147), chicken (breast, n=203; carcasses, n=71) and pigs (carcasses, n=85; trimmings, n=118). Vidas ECO detected 451 (12%) samples positive, but from only 27 (0.74%) samples was E. coli O157 isolated. One strain was isolated from bovine ground beef (0.18%), one from a pig carcass (1.17%) and all others were isolated from bovine carcasses (1.02%). All strains possessed the attaching-and-effacing gene, the enterohemorrhagic plasmid and verotoxin (VT) genes, except the strain isolated from the pig carcass that was therefore eliminated. Six of the strains were urease-positive. Strains were typed by two DNA fingerprinting methods: random amplification of polymorphic DNA (RAPD) and pulsed field gel electrophoresis (PFGE). PFGE revealed a similarity of 71.05%, while RAPD was 77.36% similar. None of the typing methods were able to classify all urease-positive strains to one pattern. Strains in the same PFGE cluster did not belong to one RAPD cluster. This paper highlights that Belgian fresh meat at retail level can be contaminated with E. coli O157 and that two different typing methods divide strains into different types.     

True retention of nutrients on cooking of Australian retail lamb cuts of differing carcass classification characteristics

The true retention of nutrients (proximate principles and cholesterol) on cooking of three retail cuts from lambs classified by weight, sex and fatness score was investigated. Fat retentions of the total cut and of the lean portion of lamb legs and mid-loin chops were not affected by carcass fatness, weight and sex or their interactions, however, the fat retention of the total cut and of the lean portion of forequarter chops was affected by fat score, with forequarter chops from fat score 1 retaining more fat than did chops of carcasses of higher fat score. Overall, fat was lost by all cuts (total cut) on cooking, with only 70–80% of fat being retained, but fat content of lean only increased on cooking (retention >100%), indicating the passage of fat into the lean portion from the external fat cover during the cooking process. Carcass factors and their interactions had little or no effect on the protein, water and ash retentions of the total cut or the lean portions of the three cuts. Cholesterol retention by the lean portion of three cooked lamb cuts was not affected by any carcass factors or their interactions. Cholesterol retentions were 99% for total cuts and tended to be 102% for the lean portions.     

Mechanical tenderisation of beef muscles for use in re-formed joints made with a cold-set binder

Three treatments, blade tenderisation (BT), needle tenderisation (NT) and enhancement by brine injection + vacuum-pulsing (VP), were applied to each of two muscles from beef forequarter, M. pectoralis profundus and M. supraspinatus, and two from the round of the hindquarter, M. semimembranosus and M. vastus lateralis. The tenderised muscles and non-treated controls were re-formed into joints using a cold-set bonding agent and tested as steaks cut from the joints. NT and VP gave a similar degree of tenderisation, as indicated by W–B shear force and taste panel, while BT had a lesser but still significant effect. Cook loss from steaks was increased by BT and NT treatments for the, tougher, forequarter but not the hindquarter muscles. The overall conclusion was that NT and VP treatments are more effective than BT but that the 3 methods are satisfactory for tenderisation of beef for production of re-formed steaks. Reduced redness and higher bacterial numbers arising from VP could render this treatment more suitable for re-formed steaks for catering than for retail sale. A supplementary trial showed that slices from roasted VP-treated re-formed joints(as distinct from grill-cooked steaks tested in the main trial) were better in sliceability and equal to or better in sensory quality than those from commercial whole-muscle round roasts purchased in a supermarket.     

Microbial assessment of an upward and downward dehiding technique in a commercial beef processing plant

Preventing microbial contamination during dehiding is challenging, and skinning methods are of critical importance for the hygienic status of beef carcasses. Two skinning methods are usually employed: upward hide pulling (UHP) and downward hide pulling (DHP). This study has compared the microbiological contamination of carcasses using both systems in a beef processing plant in the process of changing its dehiding method from UHP to DHP. 100 cm² areas from eight carcass sites (ham, chuck, rump, bung, flank, brisket, shin and neck) were sampled on 36 skinned carcasses dehided by each technique. Total viable counts (TVCs) and Enterobacteriaceae counts for each site were determined. No significant differences were observed in total (pooled-samples) carcass contamination regardless of the method used. However, significant differences (p < 0.05) in TVCs were observed at the flank, shin, brisket and neck. These differences can be attributed to possible deficiencies in the implementation of the HACCP pre-requisite programmes, and are not necessarily associated with the skinning method per se.     

The effects of electrical stimulation and ageing on beef tenderness

Seventeen beef carcasses from cattle with a range of breeds, ages and body conditions were used in this trial. The four treatments applied to each carcass were control (C), electrical stimulation (ES), ageing for 28 days (A) and electrical stimulation plus ageing for 28 days (ES + A). Post-mortem muscle pH was measured at 0, 0·5, 4 and 24h post-stimulation. Significantly lower muscle pH values (P < 0·01) were achieved by the stimulated carcass side sompared to the unstimulated side at 0·5 (pH 6·47 vs. 6·91) and 4 h (pH 5·96 vs. 6·44) post-stimulation.

Warner-Bratzler shear and taste panel methods were used to assess the tenderness of Longissimus dorsi muscle samples from each of the four treatments. The ES, A and ES + A treatments were significantly more tender (P < 0·01) than the control treatment. The ES and the A treatments resulted in a similar improvement in tenderness compared to the control. The ES + A treatment was significantly more tender (P < 0·01) than the ES treatment alone, but there was no significant difference in tenderness between the A and the ES + A treatments.     

The effect of post-exsanguination infusion on the composition, exudation, color and post-mortem metabolic changes in lamb

Twenty-four lamb carcasses were assigned to three treatment groups: (1) control (Ctr), (2) infused with 10% (vol/wt) of a tenderizing blend (NCa), and (3) NCa plus 0·015 CaCl₂ (WCa). Results indicated that the infused carcass solution was retained in the following order: shoulder > lion > leg. Infusion had no effect (P > 0·05) on drip and cooking losses in refrigerated samples. Samples frozen and then thawed from infused carcasses had greater thaw drip (P < 0·05) and cooking losses (P < 0·01) than control samples. The amounts of drip and cooking losses were in the order: WCa > NCa > Ctr. Frozen storage preserved the red color but lowered the lightness and yellowness of ovine muscles; the opposite effect was observed following refrigerated storage. Infused samples were lighter and yellower than control in both fresh and frozen samples (P < 0·01). WCa had less red color (P < 0·01) than NCa and Ctr at all times and storage conditions. Infusion lowered (P < 0·05) the temperature of carcasses over the first 3 h postmortem (pm) compared with Ctr. The rate of glycolysis was higher in infraspinatus (IS) than in longissimus thoracis et lumborum muscle (LTL or longissimus). In both IS and LTL, glycolysis was completed within the first 6 h postmortem in NCa, whereas in Ctr and WCa, it took 12–24 h for glycolysis to be completed. The rate of glycolysis was in the order: NCa > WCa > Ctr.     

Beef tenderness and sarcomere length

A wide range of muscle glycolytic rates was produced in 60 beef carcasses by applying different forms and periods of electrical stimulation immediately after decapitation; a further seven carcasses were not stimulated. The sides were subjected to normal chilling, and at 48 h one short loin per carcass was taken for tenderness evaluation and determination of sarcomere length (SL).

In the 19 relatively slow-glycolysing loins—those of 3-h pH (pH₃) above 6·3—tenderness extended over almost five panel units on a 1–8 scale, and included both the tenderest two and the toughest 10 muscles of the entire study. In the 48 loins of pH₃ below 6·3, on the other hand, tenderness ranged over only 2·5 units, and on average was a full panel unit higher than that of the high-pH₃ muscles. The most striking difference between the two groups, however, was in the relationship between toughness and shortening; the correlation of panel tenderness on SL was remarkably high in the slow glycolysers (r = 0·84), but negligible in those of faster pH decline (r = 0·16). Thus although shortening occurred to about the same extent and over the same range in both groups, it influenced tenderness and tenderness variability only when glycolysis was quite slow. A loin pH₃ of below 6·3, however, is unusual in non-stimulated carcasses, so slow glycolysis and the very wide tenderness diversity accompanying it must be expected in commercial operations that do not use electrical stimulation.