New Insights on the Impact of Cattle Handling on Post-Mortem Myofibrillar Muscle Proteome and Meat Tenderization

This study investigated the effect of different cattle management strategies at farm (Intensive vs. Extensive) and during transport and lairage (mixing vs. non-mixing with unfamiliar animals) on the myofibrillar subproteome of Longissimus thoracis et lumborum (LTL) muscle of “Asturiana de los Valles” yearling bulls. It further aimed to study the relationships with beef quality traits including pH, color, and tenderness evaluated by Warner–Bratzler shear force (WBSF). Thus, comparative proteomics of the myofibrillar fraction along meat maturation (from 2 h to 14 days post-mortem) and different quality traits were analyzed. A total of 23 protein fragments corresponding to 21 unique proteins showed significant differences among the treatments (p < 0.05) due to any of the factors considered (Farm, Transport and Lairage, and post-mortem time ageing). The proteins belong to several biological pathways including three structural proteins (MYBPC2, TNNT3, and MYL1) and one metabolic enzyme (ALDOA) that were affected by both Farm and Transport/Lairage factors. ACTA1, LDB3, and FHL2 were affected by Farm factors, while TNNI2 and MYLPF (structural proteins), PKM (metabolic enzyme), and HSPB1 (small Heat shock protein) were affected by Transport/Lairage factors. Several correlations were found between the changing proteins (PKM, ALDOA, TNNI2, TNNT3, ACTA1, MYL1, and CRYAB) and color and tenderness beef quality traits, indicating their importance in the determination of meat quality and their possible use as putative biomarkers.

Influence of Ca2+ on mitochondrial apoptosis activation and yak meat tenderization during postmortem aging

The objective of this study was to investigate the underlying molecular mechanisms of mitochondrial Ca2+ homeostasis disequilibrium in mitochondrial apoptosis and its impact on yak meat tenderness. Results indicated that CaCl2 treatment significantly promoted glycolysis by increasing lactic acid level and decreasing glycogen content, pH, and ATP production (P < 0.01 and P < 0.05). The activities of Na+-K+-ATPase pump and Ca2+-ATPase pump in the early aging stage were significantly influenced by CaCl2 treatment. The activities of synchronous digital hierarchy and citrate synthase were also significantly improved by CaCl2 treatment (P < 0.01 and P < 0.05). Mitochondrial reactive oxygen species (ROS) levels were significantly higher in the CaCl2 group than in the control group (P < 0.01); at 24 h, the value in the Ca2+ group was 64.27% higher than that in the control group. Furthermore, CaCl2 treatment significantly enhanced the mitochondrial apoptosis cascade reaction and meat tenderization by improving the myofibril fragmentation index and shear force (P < 0.01). These results demonstrated that the imbalance of mitochondrial Ca2+ homeostasis played a significant role in the mitochondrial apoptosis pathway by regulating energy metabolism factors, meat intracellular environment, mitochondrial functions, and ROS-mediated oxidative stress. These conditions further improved meat tenderization during postmortem aging.

Meat tenderization using bromelain enzyme extracted from pineapple waste

Tenderization is an important method to improve the quality and palatability of meat. In comparison to conventional chemical and physical methods of meat tenderization, enzymatic treatment is more economical and healthy. In the present study proteolytic enzyme bromelain was used for this purpose. Bromelain enzyme was extracted from pineapple, quantified and optimized concentration was used for treating the muscle fibre of meat. Tenderness was measured. pH and cooking loss were not significantly (P>0.05) decreased, but water-holding capacity and protein content were significantly (P<0.05) increased with the concentration and ageing. Duration of marination was optimized and SDS- PAGE electrophoresis was conducted to estimate protein. The results proved that bromelain enzyme is an effective method of tenderization used to improve the quality of meat.

The electrohydraulic method for meat tenderization and curing

The paper examines the problem of meat raw material curing in production of whole-piece meat products. The intensification methods for the process of penetration and distribution of curing ingredients throughout a product are described. Design of the equipment for meat tenderization URM-1 and URMP-1 is proposed, which ensure electrohydraulic tenderization of the structure of whole-piece (1500–2000 g) and portioned (80–120 g) meat semi-finished products and accelerate a process of brine distribution, which will allow reducing product strength characteristics by 51–53 kg/cm, reducing raw material losses, increasing labor productivity by 8–11%, shortening the duration of the technological process and reducing energy expenditure upon heat treatment by 18–20%. As a result of the experimental investigations, it was established that an electrohydraulic impact (frequency of pulses v = 0.5–1.0 pulse/sec., number of pulses from 150 to 200) can be used for tenderization of muscle connective tissue and tendons both of chilled (core temperature of 0 °C to 4 °C) and subfrozen (–2 °C to 3 °C) meat.