Muscle-specific physicochemical, oxidative and molecular responses to vacuum aging in beef from non-castrated males

Authors: Ramón Alberto Nieto, María Sofía Castaño Ledesma, Miriam Teresa Nediani, and María Sumampa Coria

Ger. J. Vet. Res 2026. vol. 6, Iss. 2 pp:1-14
Doi: https://doi.org/10.51585/gjvr.2026.2.0183

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Abstract:

Beef production based on non-castrated males (NCM) has gained increasing relevance due to their superior biological efficiency and reduced age at slaughter. However, concerns persist regarding meat quality attributes, particularly tenderness, oxidative stability, and shelf life. Therefore, this study aimed to evaluate physicochemical, microbiological, oxidative, and molecular changes during postmortem vacuum aging of beef from Braford NCM, with a focus on the Longissimus dorsi (LD) and Biceps femoris (BF) muscles. Samples from the LD and BF muscles from four NCM were vacuum-packaged and stored at refrigerated temperatures. Analyses were performed at 3-, 7-, 14-, and 21-days postmortem. Physicochemical parameters (pH, color, water-holding capacity, thawing and cooking losses, and Warner–Bratzler shear force), microbiological quality, oxidative status (lipid and protein oxidation, myoglobin forms, total phenolic content), gene expression of capn1, capn2, and cast, protein degradation patterns by SDS-PAGE, and excitation–emission fluorescence matrices (EEM) were evaluated. Results showed a progressive decrease in shear force in both muscles, with a more pronounced tenderization in LD, reaching 44% reduction at 14 days of postmortem aging. Vacuum packaging maintained microbial counts within acceptable limits up to 14 days of storage. LD exhibited greater oxidative stability, characterized by lower lipid and protein oxidation and a higher proportion of oxymyoglobin, whereas BF showed higher oxidative susceptibility. Gene expression analysis revealed higher cast expression in BF, consistent with its lower proteolytic activity and reduced tenderization. The sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis confirmed more extensive degradation of key myofibrillar proteins in LD.  Additionally, EEM analysis detected oxidation-related changes exclusively in BF. In conclusion, vacuum aging for approximately 14 days represents an effective strategy to improve meat quality in NCM Braford. Muscle-specific metabolic and molecular traits play a key role in determining tenderness and oxidative stability, with LD showing greater suitability for extended aging.

Keywords:

Aging, Beef quality, Calpain-calpastatin system, Oxidative stability, SDS-PAGE, Vacuum packaging

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