Freezing, thawing and aging effects on beef tenderness from Bos indicus and Bos taurus cattle

The objective of this study was to determine the effects of freezing prior to aging on the meat tenderness of young Nellore and Aberdeen Angus bulls. Samples of the longissimus thoracis muscle were submitted to two treatments: conventional aging and freezing (− 20 °C for 40 days) followed by thawing and aging periods. The meats were evaluated after 0, 7, 14 and 21 aging days (1 °C). Freezing increased (P < 0.05) purge, cooking loss and total exudate loss throughout aging. Nellore meats had greater total exudate loss and shorter sarcomere lengths (P < 0.05). Freezing increased proteolysis during aging in the meats of both breeds, but reduced shear force was found (P < 0.05) only in Aberdeen Angus meats and only at time zero. These results suggest that the meat tenderizing process by freezing prior to aging may contribute to meat tenderness in the first weeks of aging, but it is dependent on the animal breed

Relationship between the Porcine Stress Syndrome gene and pork quality traits of F2 pigs resulting from divergent crosses

The PSS genotypes of 596 F2 pigs produced by initial mating of Brazilian commercial sows and native boars were characterized by PCR-RFLP and the pork quality traits were evaluated. Among the 596 pigs studied, 493 (82.7%) were NN and 103 (17.3%) were Nn. There were no differences between NN and Nn pigs in the following pork qualities: pHu (5.71 ± 0.16 vs 5.70 ± 0.11), intramuscular fat (1.55 ± 0.64% vs 1.65 ± 0.67%), shear force (5552 ± 878 g/1.2 cm vs 5507 ± 826 g/1.2 cm), lightness (44.96 ± 2.05 vs 45.01 ± 1.92), redness (0.64 ± 0.60 vs 0.79 ± 0.55), yellowness (6.62 ± 0.56 vs 6.65 ± 0.48), hue (84.28 ± 5.53 vs 83.41 ± 4.85), or chroma (6.68 ± 0.52 vs 6.73 ± 0.52). However, pork from Nn pigs had a significantly (p < 0.05) lower pH45 (6.41 ± 0.27 vs 6.51 ± 0.26) and greater drip (3.92 ± 1.90% vs 3.06 ± 1.60%), cooking (33.29 ± 2.26% vs 32.50 ± 2.54%) and total (35.67 ± 2.48% vs 34.01 ± 2.58%) loss compared to that of NN pigs. These results indicate that, even in divergent crosses, PSS gene carriers produce pork of poorer quality