Beef Carcasses Research Articles

Characterization of decontamination procedure of beef carcasses at slaughterhouses in the province of Antioquia, Colombia

BACKGROUND: Beef slaughterhouses must use a carcass decontamination procedure to control pathogens and thus prevent foodborne diseases transmitted by meat. OBJECTIVES: This study aimed to characterize beef carcass decontamination procedures at slaughterhouses located in the province of Antioquia (Colombia). All the slaughterhouses were open, registered, and approved by Invima (Instituto Nacional de Vigilancia de Medicamentos y Alimentos in Spanish) at the time of the study. METHODS: This descriptive study collected information from 23 beef slaughterhouses between July 2019 and April 2021 through documentary reviews and visits to slaughterhouses, using forms and questionnaires. RESULTS: The study allowed the characterization of the procedures used to decontaminate beef carcasses, showing that the chemical disinfection of the carcasses is used to control microorganisms in at least 73.9% of the slaughterhouses analyzed. According to secondary sources, it was found that most of the slaughterhouses are small (slaughter volume <50,000 heads per year); 10 of them use citric acid, lactic acid, peracetic acid, and a mixture of organic acids in concentrations between 900 and 1,200 ppm, 1.5 and 1.7%, 180 and 190 ppm, and 900 and 1,200 ppm, respectively, as carcass disinfectants and according to the technical data sheet of the product. During the visits and through the application of the questionnaire, it was found that the 12 slaughterhouses had implemented chemical disinfection which is not scientifically based, using manual devices as an intervention method to control pathogenic microorganisms. It was found that the type of company, slaughter volume, and the lack of financial resources are the determining factors in the selection of decontamination procedures. The validation of the beef carcass decontamination procedures in the different slaughterhouses in the study was demonstrated. CONCLUSIONS:Although it was established that at least one decontamination procedure, such as chemical disinfection, is used in the slaughterhouses of study, this option is not supported by scientific or technical evidence. The findings support the need for improvements in the slaughterhouses of the province of Antioquia, including the improvement of surveillance programs to reduce pathogens in the meat chain effectively.

Exploring the Effects of Incorporating Egg Powder Containing Phospholipase α2 Antibody on Ground Striploin Shelf-Life

Lipid oxidation in beef may be enhanced by the hydrolysis of phospholipids by phospholipaseα2 (PLA2) during postmortem storage. Anti-phospholipaseα2 (aPLA2) is an antibody that can inhibit PLA2 activity. Past research has shown that aPLA2 can be mass-produced in the form of egg powder (EP) from hens immunized against PLA2. Therefore, the present study aimed to determine the effects of incorporating different levels of EP containing aPLA2 into ground striploin (GS) to assess its ability to extend beef shelf-life. Ten striploins were collected from 10 USDA Choice beef carcasses. Each striploin was ground and equally divided into 4 batches, and each batch was mixed with 0%, 0.4%, 0.8%, or 1.6% dried EP containing aPLA2. Each treatment batch was further divided into 3 smaller batches and subjected to retail display (0, 4, or 7d). Color descriptors, pH, proximate analysis, lipid oxidation, antioxidant capacity, and phospholipid and fatty acid (FA) profiles were measured. Percent visual discoloration and instrumental color measurements of GS were unaffected by aPLA2 EP treatments (P>0.05). The 1.6% treatment GS had a higher relative percentage of phosphatidylcholine compared with those from the 0% treatment (P<0.05), but the lack of lysophosphatidylcholine generation in the GS from any treatment reflects a lack of detectable level of PLA2 activity. Moreover, the addition of EP in GS increased the relative percentage of FA 11-18:1, 18:2, 20:1, and 22:6 (P<0.05). As a result, there was more lipid oxidation for GS from the 1.6% treatment compared with those from the 0% treatment (P<0.05), but GS from the 0.8% treatment showed higher antioxidant activity than those from the 0% treatment (P<0.05). In this study, the addition of EP containing aPLA2 did not demonstrate any effect to extend shelf-life when incorporated into GS.

Beef carcass microbiota after slaughtering and primary cooling: A metataxonomic assessment to infer contamination drivers

The impact of primary cooling on beef microbiota was investigated on six beef carcasses consecutively processed with the parallel use of metataxonomic and culture-dependent analysis. Samples were collected immediately after slaughtering (AS) and after the 24th-hour post-cooling (PC) from three different surfaces, namely neck, flank and thigh.The main objective was to examine whether the microbiota composition of beef carcasses changes as function of the surface sampled, primary cooling (from AS to PC) and animal’s origin (breeder).The outcomes underline that primary cooling did not affect qualitatively the composition of the potentially active microbiota or the carcass superficial counts. Although slight changes in chemical-physical parameters like volatile organic compounds (VOCs) were observed after cooling, the carcasses microbiota and its inferred metabolic pathways varied among animals as a function of their origin. Co-occurrence and co-exclusion analyses underlined competition for the colonisation of the carcass surface between Brochothrix-Psychrobacter and Carnobacterium-Serratia-Pseudomonas.Once integrated in a comprehensive monitoring of the supply chain, the metataxonomic characterisation of the beef carcasses microbiota might represent a valid integrative approach to define the cuts’ perishability and their appropriateness to specific packaging and storage methods. These new bits of knowledge could be the base to define good strategies for the prevention of meat spoilage.

Evaluation of the Microbiological Status of Cattle Carcasses in Mongolia: Considering the Hygienic Practices of Slaughter Establishments.

The meat industry has received great attention in Mongolia, having over 70 million livestock, and is important to the nation's economy. Systematic microbiological testing of carcasses has not been mandatorily regulated in all abattoir premises, and the efficacy of the introduction of the Good Hygiene Practice and Hazard Analysis Critical Control Points (HACCP) to some plants has not yet been tested microbiologically in Mongolia. Therefore, samples were collected from two establishments: plant A with an HACCP certificate from a third party and plant B without an HACCP certificate. The rates and levels of the total bacterial count (TBC) as overall hygiene indicators, the Enterobacteriaceae count (EBC) as fecal contamination indicators, and the Staphylococcus spp. count (SC) as personal hygiene indicators were determined on different parts of beef carcasses. The contamination rates in most parts were lower in plant A than in plant B (e.g., TBC in the rump and flank: 103-105 and 105-107, in plant A vs. 104-106 and 105-108 in plant B, respectively). Plant A also had a lower EBC and SC (p < 0.001). Furthermore, 2 out of 100 beef carcasses (2%) were positive for enterohemorrhagic Escherichia coli as a foodborne pathogen indicator in plant A.

Isolation, characterization and antimicrobial resistance of Yersinia enterocolitica from Polish cattle and their carcasses

BackgroundYersinia enterocolitica is a heterogeneous bacterial species that has been divided into six biotypes and more than 70 serotypes. Each year, the European Food Safety Authority classifies yersiniosis caused by Y. enterocolitica as one of the most important zoonotic diseases. The prevalence of Y. enterocolitica in cattle has not been thoroughly analyzed in Poland, and beef and bovine carcasses contaminated with antimicrobial resistant Y. enterocolitica pose a health risk for both, farm workers and consumers. Therefore, the aim of this study was to evaluate the prevalence of Y. enterocolitica in cattle and to determine the antimicrobial susceptibility of the isolated strains.ResultsA total of 1020 samples were analyzed, including 660 rectal swabs collected from live cattle and 360 swabs from cold-stored beef carcasses. The results of this study indicate that Y. enterocolitica was isolated from three of the 15 examined cattle herds and the prevalence within these herds ranged from 0% to nearly 32%. Y. enterocolitica was isolated from 14.7% of the examined heifers, 7.4% of calves and 5.5% of adult cows. More than 65% of the strains were isolated from cold enrichment. The strains isolated from live cattle tested positive for the ystB gene, while ail and ystA genes were not found. Most of the isolated strains belonged to bioserotype 1A/NT. The majority of the isolated strains were resistant to ampicillin, cefalexin and amoxicillin with clavulanic acid, however these are expected phenotypes for Y. enterocolitica.ConclusionsThe results of this study indicate that Y. enterocolitica is present in cattle herds in Poland. The strains isolated from live cattle were ystB-positive, most of them belonged to bioserotype 1A/NT. The prevalence of Y. enterocolitica strains was generally low in cold-stored beef carcasses.

Evaluation of Antimicrobial Resistance Profiles of Bacteria Isolated from Biofilm in Meat Processing Units.

The aim of this study was to assess the hygiene of pork, beef, and poultry carcasses and to determine the phenotypic antibiotic susceptibility of the bacteria embedded in the biofilm formed on the carcasses kept in cooling chambers for at least three days. The level of hygiene was assessed by determining the total aerobic colony count (TACC) and the Enterobacteriaceae level in different sampling points of the carcasses, along with the detection of E. coli and Pseudomonas spp. embedded in the biofilm. Furthermore, the E. coli and Pseudomonas spp. isolates were tested for antimicrobial resistance profiles. A total of 130 samples collected from pork, beef, and poultry from processing units were analyzed to determine the total aerobic colony count as well as to measure the level of Enterobacteriaceae found on the carcasses. The antimicrobial susceptibility of 44 Escherichia coli and eight Pseudomonas spp. strains isolated from the carcasses were assessed using the Vitek 2 system using two different cards. Overall, the regulatory limits for the TACC were exceeded in 7.6% of the samples, and 65% of the samples exceeded the regulatory limits for Enterobacteriaceae levels. The antimicrobial susceptibility tests of the E. coli isolates analyzed with the AST-GN27 card revealed the highest resistance to be that towards ampicillin (76.1%), followed by cefazolin (71.4%), amoxicillin/clavulanic acid (61.9%), nitrofurantoin (52.3%), cefoxitin (47.6%), tetracycline (38.1%), piperacillin, norfloxacin (19%), trimethoprim-sulfamethoxazole (11.9%), cefotaxime (9.5%), ceftazidime, cefazolin, amikacin, gentamicin, and ciprofloxacin (4.7%). However, all of the isolates were sensitive to piperacillin-tazobactam and imipenem. Thirty-two (61.5%; 95% CI 47.9-73.5) out of fifty-two isolates exhibited multidrug resistance, resulting in the expression of 10 resistance profiles. The findings of this study highlight serious hygienic and sanitary deficiencies within the meat processing units and demonstrate that the resulting meat can harbor Multidrug-resistant Escherichia coli and Pseudomonas spp., both of which pose a serious public health risk. However, further research with a larger number of samples is required to reach thorough results.

Compact imaging system and deep learning based segmentation for objective longissimus muscle area in Korean beef carcass

With growing consumer interest in meat quality, the need for accurate quality assessment becomes increasingly important. One crucial factor of Korean beef quality is the longissimus muscle area, which is closely associated with both quality and yield grade. Currently, the measurement is visually assessed, introducing subjectivity and placing a substantial burden on inspectors in terms of labor. To address these challenges, we have developed a compact image acquisition system designed to acquire accurate grading assessment images of beef carcasses. Several preprocessing steps after image acquisition were conducted, including radial distortion correction and color calibration. We have employed conventional image-processing techniques and four deep-learning models to segment the longissimus muscle area using the calibrated images. Among the segmentation models, DeepLab model based on ResNet50 achieved the highest accuracy. It demonstrated a Global Accuracy, Weighted IoU, and Mean BF Score of approximately 99.26%, 98.54%, and 95.70%, respectively. The results of our study are expected to contribute to the development of objective criteria for loin area assessment. By enabling precise and consistent determination of beef carcass quality, our research has the potential to reduce labor requirements for inspectors and provide a standardized approach to assessing loin area.

Mitigation of greenhouse gas emissions in pasture-based dairy-beef production systems

CONTEXTAgriculture and food systems contribute significantly to climate change. Greenhouse gas (GHG) emissions intensity from beef production are high when compared to other livestock production systems and, therefore, mitigation of these emissions is urgently required. In many countries dairy-beef is making a large and growing contribution to total beef output thereby reducing net emissions given the lower emissions intensity of beef originating from the dairy herd when compared to specialized beef-cow systems. GHG emissions from dairy-beef systems can be further reduced by adopting best practice and mitigation technologies. OBJECTIVESThe objectives of this study were to (1) evaluate a range of management practices to reduce GHG emissions for pasture-based beef cattle production systems, (2) model the individual and combined impacts of these management practices on GHG emissions from dairy-beef systems, and (3) identify any trade-offs between GHG emissions mitigation, farm profitability, food security and land use. METHODSA farm level bioeconomic systems model was modified to evaluate spring-born, steer production systems finishing cattle at differing slaughter ages and from contrasting forage-based finishing diets (grazed grass or grass silage, each supplemented with concentrates). Mitigation measures included earlier slaughter age, optimal slurry management, urease inhibitors for nitrogen (N) fertilizers, replacing cereals with ‘by-products’ in concentrate feed rations and incorporating clover in grassland pastures. RESULTS AND CONCLUSIONSCombining mitigation strategies reduced dairy-beef systems GHG emissions intensity by an average of 21%. Incorporating clover in grassland pastures was found to be the most profitable stand-alone mitigation strategy increasing net margin by an average of 18%. Substituting by-products for barley in a concentrate ration converted all systems into net producers of human edible protein; otherwise, steer systems finishing at pasture during the third grazing season were the only net producers of human-edible protein. However, finishing at pasture during the third grazing season increased GHG emissions per animal and per kilogram of beef carcass. SIGNIFICANCEWithin a grass-based dairy-beef system, such as that modelled in this study, a number of complementary GHG emissions mitigation strategies can be implemented, without making substantive changes to the production system, while simultaneously improving farm profitability.

Retrospective Assessment of Greenhouse Gas Emissions from the Beef Sector in Greece and Potential Mitigation Scenarios

Although beef production is one of the most valuable drivers of the global livestock economy, it is considered the main contributor to GHG emissions derived from livestock. This study’s objectives were to estimate the GHG emissions (expressed in carbon dioxide equivalents; CO2-eq) from the beef sector in Greece at the national and prefecture levels during the period 2011–2021 and to explore potential mitigation scenarios. The Tier 1 and 2 methodologies were implemented to estimate the GHG emissions. The total estimated emissions increased over the study period. Although both methodologies captured similar trends in the changes in GHG emissions, the Tier 2 estimations revealed lower emissions and fluctuations due to the different and more precise computational approaches. At the prefecture level, fluctuations in emissions were also noted. However, specific regions showed higher increases in emissions. The observed increase in emissions, in terms of either absolute values (Gg CO2-eq) or intensities (Kg CO2-eq/Kg produced beef carcass), is of utmost importance, and further mitigation strategies should be considered. The regression analysis showed a good predictive ability for emissions, using the number of livestock animals as the input. The equations derived from this analysis could be further used as first-approach tools for capturing future emissions at the national level before proceeding with more elaborate approaches. The different scenarios examined in response to the sector’s challenges showed moderate changes in GHG emissions. Depending on national priorities, such scenarios could serve as pilot case studies, which may assist stakeholders in improving the sustainability of the sector in the future.

Impact of the duration of rearing and finishing periods on steer performance and carcass and meat quality characteristics

The present study evaluates the effects of extending the rearing period on pasture for 0, 49, and 98 d (beyond 300 kg of live weight) and of finishing on a concentrate diet for 49 and 98 d on beef carcass quality, meat and subcutaneous fat color, shear-force, fatty acid profile and on consumer sensory quality of meat. No major interactions were observed throughout the study. Increasing the rearing period increased slaughter and carcass weight and fat thickness with no other effects on meat quality. Extending the finishing period increased slaughter and carcass weight, fat thickness, and longissimus muscle area with no effects on meat color, shear-force and cooking loses. Longissimus fatty acid profile was altered by extending the finishing period with greater amounts of total FA and proportion of C18:1 cis-9 while decreasing the proportion of n-3 polyunsaturated FA. There were no effects of extending the rearing and finishing periods on consumer evaluation of sensory traits. However, evaluation of consumer clusters found greater overall and flavor liking scores for meat from steers with the shortest rearing period for Cluster-1 while Cluster-2 gave greater flavor liking scores to beef from steers where the finishing period was extended. The results suggest slaughter weight can be increased by extending the finishing period without negatively affecting consumer quality, while extending the rearing period may have a negative impact on.

Impact of a constant current electrical stimulation (CCES) system and hormonal growth-promoting (HGP) implants on meat quality and palatability of finished steers

This study evaluated the effects of a constant current electrical stimulation (CCES) system and hormonal growth-promoting (HGP) implants on the quality and palatability of the longissimus thoracis et lumborum (LTL) from yearling-finished steers. The experiment used a total of 46 Angus cross steers, which were either non-implanted (n = 20) or implanted with trenbolone acetate and estradiol benzoate (n = 26). The CCES was applied to one side of each carcass during the slaughter process, whereas the other side remained unstimulated. Regardless of the application of HGP implants, the CCES reduced pH at 3 and 72 h post-mortem and shear force at all ageing times (P < 0.05), improved colour at 72 h post-mortem and during the retail display (P < 0.05), increased initial and overall tenderness (P < 0.01), and decreased the amount of perceived connective tissue and the proportion of trained panelists detecting spongy texture (P < 0.05) compared to meat from unstimulated carcass sides. Although CCES increased meat purge losses and reduced moisture content (P < 0.05), this did not affect meat juiciness (P > 0.10). CCES interacted with HGP to prevent increase in drip loss (P > 0.10), increase frequency of panelists detecting bloody/serumy flavour and typical texture, and reduce the proportion of panelists detecting rubbery texture in meat (P < 0.05). Regardless of stimulation treatment, meat from implanted animals had a more pronounced pH decline at 72 h post-mortem (P < 0.05) and a higher proportion of panelists finding no off-flavours (P < 0.05) or bloody/serumy flavour (P < 0.01) than non-implanted cattle. The CCES system tested in this study improved LTL quality and palatability of heavier beef carcasses.

Effect of delayed timing of artificial insemination with sex-sorted semen on pregnancy per artificial insemination in synchronized dairy heifers managed in a seasonal-calving pasture-based system

The objective of this study was to evaluate the timing of artificial insemination (AI) with frozen-thawed sex-sorted semen on pregnancy per AI (P/AI) in dairy heifers. A 6-d progesterone Co-Synch protocol was used for ovulation synchronization of dairy heifers, with timed AI (TAI) coincident with (TAI-0) or 8 h (TAI-8) after the second injection of GnRH, corresponding to either 48 h or 56 h after removal of the progesterone-releasing intravaginal device. Pregnancy diagnosis was conducted by transrectal ultrasound scanning of the uterus 34 d after TAI (n = 816 records available for analysis). Generalized linear mixed models were used to examine the effects of treatment on P/AI. Treatment (n = 2), herd (n = 11), and treatment × herd were included as categorical fixed effects. Heifer body weight and Economic Breeding Index values for milk production, fertility, calving performance, beef carcass, cow maintenance, cow management, and health were included as continuous fixed effects. Heifer ID was included as a random effect. Pregnancy per AI was greater for TAI-8 heifers (59%) compared with TAI-0 heifers (50%). Pregnancy per AI ranged from 38% to 75% between herds but there was no treatment × herd interaction. The fertility subindex (positive) and the cow management subindex (negative) were the only continuous animal variables associated with P/AI. Delaying the timing of AI with frozen-thawed sex-sorted semen by 8 h in dairy heifers enrolled on a 6-d progesterone Co-Synch protocol improved P/AI.

Escherichia coli O157:H7 beef carcass contamination and its antibiotic resistance in Awi Zone, Northwest Ethiopia.

Escherichia coli O157:H7 is a cause of foodborne disease and global public health issues especially in developing countries like Ethiopia. A cross-sectional study was done from January 2022 to July 2022 in Awi Zone to assess the occurrence and antibiograms of E. coli O157:H7. Abattoirs and butcher shops were selected purposively, whereas a systematic random and purposive sampling technique was employed to select study units in abattoirs and butcher shops, respectively. A total of 248 swab samples were collected, isolated, and confirmed using bacteriological culture, biochemical tests, and latex agglutination tests. Escherichia coli O1157:H7 antibiogram tests were performed using Kirby-Bauer disk diffusion method. Logistic regression was used to analyze and measure the degree of association between the presumed risk factors and E. coli O157:H7 occurrence. The overall occurrence of E. coli O157:H7 was estimated to be 8.87% and a relative higher (11.29%) occurrence of E. coli O157:H7 was recorded at butcher shops when compared to abattoirs (6.45%). All isolates were susceptible to gentamicin followed by chloramphenicol (81.81%). About 81.81% of the isolates were resistant to ampicillin and 77.23% of isolates developed resistance to two and more than two antibiotics (MDR). In conclusion, E. coli O157:H7 was detected in the study area. Thus, educating abattoir and butcher shop workers, and consumers, on hygienic handling practices and safe consumption of meat could eliminate foodborne infection associated with E. coli O157:H7 occurrence.

Proteome changes in Neck-arm restraint and Achilles tendon suspensions during early post-mortem aging in cattle

The aging process of beef is impacted by the suspension method and aging time during the postmortem process. The neck-arm restraint (NR) suspension can accelerate the aging of beef carcasses compared with Achilles tendon (AT) suspension. However, the muscle protein changes between these two suspension methods in early postmortem aging are still unclear. This study aimed to investigate the proteomes of longissimus thoracis (LT) muscles between AT and NR suspension methods at 1 h and 72 h postmortem by the multiplexed isobaric tagging technology for relative quantitation (iTRAQ) technique and uncover the critical protein biomarkers of beef quality. A total of 59 proteins were differentially expressed between different suspension methods or postmortem aging times, which were mainly involved in actin cytoskeleton reorganization, actomyosin structure organization, response to calcium ions, and muscle contraction. Through the analysis of protein-protein interaction (PPI), we detected that ALB, APOA1, FGA, and TTN could be served as the hub proteins. Integration with the reported quantitative trait loci (QTL) of beef quality revealed that 30 differentially expressed proteins (DEPs) were involved in 46 QTL, in which, 11 proteins were differentially expressed in both the suspension method and time point comparison groups. We inferred these 11 proteins (MYL6B, MYO1A, COL3A1, AFP, CLN6, FGB, GLS2, BAG4, FGG, A2M, and WNT10A) as the most promising markers for the beef quality during the aging process.

Physical Composition Of Beef Carcass To Selling Price

The cattle industry in Indonesia is very important because it can provide an adequate supply of meat for the community. However, the cattle industry in Indonesia still faces various challenges, such as increasing production costs and low productivity. One way to overcome these challenges is to feed cattle with technology. The purpose of this study was to identify the effect of the physical composition of beef carcasses on the selling price of beef fed with technological feed. This study used a qualitative method with a descriptive approach. Data were collected using observation and literature study techniques. The results showed that the physical composition of cattle carcasses affects the selling price of beef. Cattle with heavier carcasses and a higher percentage of meat tend to have a higher selling price. In addition, cattle with a lower percentage of fat also tend to have a higher selling price. These findings suggest that the use of feed technology can improve the physical composition of cattle carcasses and increase the selling value of beef

Molecular Pathways for Muscle and Adipose Tissue Are Altered between Beef Steers Classed as Choice or Standard.

Targets for finished livestock are often determined by expected fat, either subcutaneous or intramuscular. These targets are used frequently to improve eating quality. Lower intramuscular fat, lack of product uniformity, and insufficient tenderness can negatively impact beef acceptability. This study aimed to investigate the differences in gene expression that alter metabolism and intercellular signaling in the muscle and adipose tissue in beef carcasses at different fat endpoints. In this study, longissimus thoracis muscle samples and adipose tissue were collected at harvest, and RNA was extracted and then sequenced using RNAseq. Differential expression was determined using edgeR, and p-values were adjusted using the Benjamini-Hochberg method. A corrected p-value of 0.005 and log2 (fold change) of >1 were the threshold to identify differential expression. Comparison between intermuscular and subcutaneous fat showed no differences in the genes activated in the two adipose tissue depots, suggesting that subcutaneous fat was an adequate sample. Carcass data allowed the classification of carcasses by USDA quality grades (marbling targets). In comparing muscle from Standard and Choice carcasses, 15 genes were downregulated, and 20 were upregulated. There were 49 downregulated and 113 upregulated genes comparing adipose tissue from Standard and Choice carcasses. These genes are related to the metabolism of fat and energy. This indicates that muscle transcript expression varies less than adipose. In addition, subcutaneous fat can be used to evaluate transcript changes in fat. However, it is unclear whether these fat tissues can be used as surrogates for marbling.

Effects of pelvic suspension of beef carcasses and wet aging time of cuts on eating quality and sensory scores of 14 muscles

Abstract To evaluate the effect of carcass hanging method and aging period on beef eating quality young cross-breed bulls were slaughtered in a slaughterhouse in south-eastern Poland. After the slaughter operations were completed, one carcass side was hung by the Achilles tendon and the other by the hip bone. Suspension methods depending on the carcass sides were used in rotation. Consumer samples were prepared from 14 muscles collected from each of the 50 sides. The use of different hanging methods showed their varied impact on tenderness, juiciness, flavour overall liking and eating quality of beef cuts. A positive effect of tenderstretch on eating quality was observed for six of the muscles (longissimus thoracis, spinalis dorsi, longissimus lumborum, vastus lateralis, gluteus profundus and semimembranosus), no effect was observed for seven, and a negative effect of suspending carcass by hip bone was noted for just one muscle.

Carcase grading reflects the variation in beef yield – a multivariate method for exploring the relationship between beef yield and carcase traits

Beef carcases in Europe are classified as a proxy for the quantity and ratio of tissues, commonly referred to as yield. It is important that proxies accurately measure yield as they contribute to financial transactions between abattoirs and producers. The main purpose of the study was therefore to examine the ability of EUROP carcase classification to explain the variation in yield. Furthermore, the effect of breed, as a confounder, was also examined. A multivariate definition of yield separating the carcase into six product categories was utilised as a response in a linear regression analysis. The conclusion was that EUROP and carcase features explain the majority of yield variation. Breed has an effect on yield beyond what is explained by carcase features including classification. The magnitude of the breed effects varies with breed and product category.

The Role of Catalase and Pyruvate on the Recovery of Cold - Shocked Bacteria

The study principally aimed at evaluating different additives to the culture medium for the recovery of cold-shocked bacteria isolated from chilled carcasses. Sixty randomly selected beef carcasses were assigned for investigation from which 630 swabs were collected for assessment of microbiological contamination of carcasses during the processes after skinning and evisceration, along the washing to the chilling stage. Obtained results were analysed by statistical package (SAS 2000, version 9.0) and revealed bacterial counts decreased significantly (p≤0.05) from skinning to chilling (3.67±0.0 to 1.23±0.10, p≤0.01). The predominant bacteria isolated from the carcasses were Staphylococcus spp. followed by Enterobacteriaceae and Pseudomonas spp. To test for recovery of cold-shocked bacteria, the bacterial load as CFU was evaluated after treatments with catalase, pyruvate and their combination. The CFU of samples from chilled carcasses increased after treatment with catalase and pyruvate (1.23±0.52 vs. 2.54±0.12 and 2.42±0.33, respectively; p≤0.05). The results showed that catalase treatment has induced higher bacterial recovery compared to pyruvate alone or the combination of pyruvate and catalase, but the bacteria died when the concentration of catalase and pyruvate was increased. Addition of catalase or pyruvate to plate count agar medium gives true estimates of the bacterial load of chilled carcasses and other cold foods.

Muscle Profiling of the Biceps Femoris, Gluteus Accessorius, and Gluteus Medius Comprising the Beef Top Sirloin Butt

Muscle profiling improves value and optimization of beef carcasses by expanding knowledge of physical, com-positional, and marketable attributes of single-muscle cuts. Extensive profiling for individual muscle portions of the NAMI #184 beef top sirloin butt remains understudied. The objective was to compare fluid loss, objective color (L*, a*, b*), pH,and objective tenderness of the biceps femoris (BF), gluteus accessorius (GA), gluteus medius, dorsal (GMD), and gluteus medius, ventral (GMV). Beef top sirloin butts (N=70) were collected from carcasses ranging in quality grade (USDA Select and Top Choice), hot carcass weight (light≤362 kg, medium=363 to 453 kg, heavy≥454 kg), and ribeye area (REA; small≤27.8 cm2, medium=27.9 to 40.6 cm2, large≥40.7 cm2). Warner-Bratzler shear force values were the low-est for the BF and GA (P&amp;lt;0.001) and were significantly different than the GMD and GMV. The GA reported the lowest percentage of fluid loss in raw and cooked forms (P&amp;lt;0.001, P&amp;lt;0.001) and the highest pH (P&amp;lt;0.001). The GMD exhibited the highest percentage of raw purge (P&amp;lt;0.001), highest L* value (P&amp;lt;0.001), and highest shear force (P&amp;lt;0.001). The GMV had the highest percentage of cook loss (P&amp;lt;0.001). USDA Top Choice muscles were more tender than Select (P&amp;lt;0.001) with higher L* value (P&amp;lt;0.001). All 4 top sirloin muscles and muscle subunits had average peak shear force values below 3.9 kg, and thus, all were within the threshold for USDA “very tender.” These muscle profiling data will aid in identifying new beef value cuts from the top sirloin butt and assess acceptability of sirloin cuts for further retail and foodservice merchandising opportunities.