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Genetic correlations between 16 meat quality and nutritional value traits and live weight at various ages, live ultrasound fat and muscle depth, carcass measures, and carcass dissection traits were estimated for Merino sheep in the Information Nucleus (IN). Genetic correlations between live weight at various ages and the carcass traits are also reported. The IN comprised 8 genetically linked flocks managed across a range of Australian sheep environments. Meat quality traits included between 1,200 and 1,300 records for progeny from over 170 sires for intramuscular fat (IMF), lean meat yield (LMY), shear force (SF5), pH, meat color, and meat nutritional value traits including iron and zinc levels and long-chain omega-3 and omega-6 polyunsaturated fatty acid levels. The genetic correlations indicated that selection of Merino sheep to either reduce fat or increase muscle using ultrasound assessments will result in little change in IMF and SF5. Myoglobin levels would tend to be reduced following selection for reduced ultrasound fat depth (0.35 ± 0.21, 0.43 ± 0.14), whereas increases in myoglobin levels would occur due to selection for increased ultrasound muscle depth (0.25 ± 0.24, 0.38 ± 0.15). Selection for increased live weight will result in favorable correlated responses in hot carcass weight (0.76 to 0.97), dressing percentage (0.13 to 0.47), and carcass muscle (0.37 to 0.95), but unfavorable responses of increases in carcass fatness (0.13 to 0.65) and possible small reductions in muscle oxidative activity (−0.13 ± 0.14 to −0.73 ± 0.33) and iron content (−0.14 ± 0.15 to −0.38 ± 0.16), and a possible deterioration of shear force from selection at later ages (0.15 ± 0.26, 0.27 ± 0.24). Negligible changes are generally expected for LMY and meat color traits following selection for increased live weight (most genetic correlations less than 0.20 in size). Selection for increased LMY would tend to result in unfavorable changes in several aspects of meat quality, including reduced IMF (−0.27 ± 0.18), meat tenderness (0.53 ± 0.26), and meat redness (−0.69 ± 0.40), as well as reduced iron levels (−0.25 ± 0.22). These genetic correlations are a first step in assisting the development of breeding values for new traits to be incorporated into genetic evaluation programs to improve meat production from Merino sheep and other dual-purpose sheep breeds.

In order to improve beef color and color stability, step-chilling (SC) was applied on excised bovine longissimus lumborummuscle, with chilling starting at 0–4°C for 5 h, then holding the temperature at 12–18°C for 6 h, followed by 0–4°C again until 24 h post-mortem. pH and temperature were measured during rigor on SC loins as well as those subjected to routine chilling (RC, 0–4°C, till 24 h post-mortem). Color L*, a*, b* values, metmyoglobin (MetMb) content, MetMb reducing ability (MRA) and NADH content were determined on samples aged for 1, 7, and 14 d. Sarcoplasmic proteome analysis was only conducted on d 1 samples. The results showed muscles subjected to SC maintained a temperature at around 15°C for 5 to 10 h post-mortem, and exhibited a slow temperature decline, but rapid pH decline. Beef steaks treated with SC had higher L*, a*, b* and chroma values than those of RC samples at 1 and 7 d chilled storage (0–4°C), while showing no significant difference for a*, b* and chroma values at d 14. The SC samples also exhibited a lower relative content of surface MetMb, higher MRA and NADH content, compared with RC beef steaks during storage, indicating the SC-treated beef showed an improved color stability. Eleven differential protein spots/nine proteins were identified by two-dimensional gel electrophoresis and mass spectrometry, and those proteins were mainly involved in redox, chaperone binding, metabolic and peroxidase activity. Oxidoreductases play a role in decreasing the oxidation-induced myoglobin oxidation and benefiting the production of NADH, and finally improving the colour of beef. Of these, pyruvate dehydrogenase E1 component subunit beta showed a positive correlation with color L*, a*, b* values and accounted for more than 60% of the variation in color values; this protein can be considered as a potential beef color biomarker. The present study provided valuable information for studies on the molecular mechanism of color improvement from step-chilling, as well as for identifying markers associated with beef color.

This study investigated the pH/temperature decline of beef carcasses in a typical Chinese abattoir and color development as pH declined during rigor onset. A natural cubic spline model was used to model the pH/temperature decline for those carcasses which passed through pH 6.0. Six of the 97 carcasses that exhibited a high (≥6.10) ultimate pH (pHu) (dark-cutting) in the M. longissimus lumborum(LL) were sampled, along with the same numbers of normal pHu and intermediate pHu carcasses (5.40–5.79; 5.80–6.10, respectively), to examine color development within 24 h postmortem. It was shown that 66.7% of the modeled carcasses were outside the ideal pH/temperature window with a temperature@pH6.0 lower than ideal, suggesting the need for acceleration of the pH decline. The stable and low a*, b*and chroma values of high pHu beef within the first 12 h indicated dark-cutting beef might be detected earlier than expected.

Background: Meat packaging once acted primarily as an inert barrier to protect its contents against contamination and this function has shifted. Discussion: Packaging now includes complementary functions that improve product quality, longevity and customer/retail appeal. The devices and methods applied to achieve these functions may be categorised as smart packaging, which includes intelligent packaging, devised to monitor and communicate packaged content status, and active packaging, to provide passive adjustment of inpack conditions from its interactions with the packaged meat. Conclusion: Smart packaging examples already available from recent patents include antimicrobial and antioxidant packaging coatings and inserts; sensors or indicators that identify spoilage and freshness; functional engineering customisations; improvements to packaging integrity; leak or tamper detectors; and, environmentally sustainable options. Together, these inventions respond to industry and customer demands for meat packaging and are therefore the focus of this review, in which we discuss their applications and limitations in meat packaging.