The meat quality of different pig breeds is associated with their different muscle tissue physiological processes, which involves a large variety of genes related with muscle fat and energy metabolism. Understanding the differences of biological processes of muscle after slaughter is helpful to reveal the meat quality development of different breeds. Therefore, eight native Large Black pigs (BP), with high fat content in meat, and seven cross-bred commercial pigs (CP), which had a high feed efficiency with high lean meat, were used to investigate the differences in their meat quality and RNA transcriptomes. The average daily gain (ADG) and hot carcass weight (HCW) of CP were higher than BP, but the back-fat thickness of BP was higher than CP (p < 0.05). The CP had higher a* (redness) but lower h (hue angle) than BP (p < 0.05). The metmyoglobin (MMb) percentage of CP was higher (p < 0.05) than BP. The fat content and oxygen consumption of longissimus dorsi (LD) muscles in BP were higher (p < 0.05) than CP. BP had higher monounsaturated fatty acids (MUFA) content, but CP had higher polyunsaturated fatty acids (PUFA) content (p < 0.05). The RNA-seq data highlighted 201 genes differentially expressed between the two groups (corrected false discovery rate (FDR) p < 0.05), with 75 up-regulated and 126 down-regulated genes in BP compared with CP using the fold change (FC). The real-time PCR was used to validate the results of RNA-seq for eight genes, and the genes related to lipid and energy metabolism were highly expressed in BP (p < 0.05). Based on the results, BP had superior intramuscular fat content to CP, while the growth performance of CP was better, and the transcriptomic differences between these two groups of pigs may cause the meat quality and growth performance variance.

The objective of this study was to assess the impacts of product sizes and subsequent consumer freezing practices on beef quality and palatability. Paired beef strip loins (LL), top sirloins (GM), and eye of rounds (ST) from 15 United States Department of Agriculture (USDA) Low Choice beef carcasses were collected, and each side was assigned into 2 freezing sizes, section (SEC) or steak (STK). Each muscle was also cut into 3 equal portions and randomly assigned to one of the 3 freezer types: blast freezer (BLS), chest freezer (CST), or refrigerator freezer (FRI). Portions assigned to STK were further cut into steaks (2.54 cm). Samples were vacuum sealed and frozen for the first 35-d freezing cycle in a −20°C BLS, then thawed until the internal temperature reached 2°C. After thawing, samples were subjected to a second 35-d freezing cycle based on the assigned freezer types and thawed using the previous method. Samples were then subjected to quality and palatability analyses, with SEC samples fabricated into 2.54-cm steaks before analysis. Product size affected the pH of all muscles, showing SEC had a lower pH than STK (P < 0.05) in LL and GM, while the inverse was observed in ST. The ST muscle pH was influenced by the freezer, with FRI having the highest pH (P < 0.05). No clear pattern was observed in water-holding capacity, although SEC freezing generally had greater purge loss compared with STK. Regardless of muscles, SEC freezing significantly improved color quality and stability compared with STK samples, showing greater redness and lower discoloration (P < 0.05). The consumer sensory panel found minimal differences in palatability quality and acceptability in LL and ST treatments (P > 0.05), whereas SEC-FRI rated lower in tenderness and overall acceptability in GM (P < 0.05). The current results suggest that product size has a greater impact on determining final frozen meat quality compared with freezer types.

This study evaluated the impact of treated dry-aged crust inclusions on final ground beef quality. Ground beef (80 lean: 20 fat) was divided into: CON (beef only), NTC (non-treated crust), WW (warm-water-washed crust), DH (dehydrated crust), and SV (sous-vide crust). Treated crusts were chopped, mixed with ground beef (10% inclusion), reground, formed into patties, and subjected to quality and microbial analyses. The pH for day 1 (d1) samples was lower than for day 7 (d7) samples regardless of treatment (p < 0.05). No differences were found for proximate analysis, cook loss, or display loss (p > 0.05). An interaction effect was observed for all color traits (p < 0.05), demonstrating rapid color decline during display in both NTC and WW treatments compared to other treatments. Greater lipid oxidation was observed in CON compared to other treatments before and after display (p < 0.05). The CON, DH, and SV treatments had lower microbial concentrations than NTC and WW (p < 0.05). Texture profile analysis showed elevated hardness values in SV compared to CON, NTC, and WW, while DH did not differ from any treatment (p < 0.05). Our results indicate that DH and SV interventions minimally impact product quality while reducing initial microbial concentrations, suggesting potential use as intervention methods for dry-aged crust.