Assessment of the effects of dry and wet aging on dark-cutting Nellore beef meat by TD-NMR and 1H NMR approaches☆

This study assessed the physicochemical parameters, water distribution, and metabolic profiles of wet- and dryaged dark-cutting Nellore beef meat using TD-NMR and 1H NMR techniques alongside chemometric analysis. We analysed eight Nellore carcasses (Longissimus lumborum) aged for 28 days using both wet and dry methods. Postaging, we noted significant reductions in water activity and moisture content in dry-aged samples, while lipid levels remained largely unchanged compared to unaged samples. However, both protein and carbonyl contents increased significantly with aging. Wet- and dry-aged samples also showed enhanced tenderness compared to non-aged beef. TD-NMR analysis identified four typical T2 components related to water distribution. Significant correlations Pearson were found between Aw, moisture and shear force and muscle water properties with moderate correlation found between Aw (inner) and T2.1 time constant. 1H NMR metabolic profiling identified 29 metabolites, including amino acids, dipeptides, and organic acids. Notably, levels of isoleucine, valine, threonine, alanine, and fumarate increased significantly after both aging processes. Acetate, creatinine, and betaine levels also increased significantly, while arginine and glycerol showed slight increases. In contrast, IMP content decreased significantly, while hypoxanthine content increased. These changes suggest metabolite accumulation that contributes to the enhanced flavour, taste, and tenderness of aged beef. This pilot study offers valuable insights that could help define optimal aging protocols for dark-cutting beef, potentially increasing the value of these meat products.