Quality Changes of Yak Meat during Wet Aging

To investigate the quality changes of yak meat during wet-aging, the longissimus dorsi muscles from healthy grazing yaks aged 24~36 months were vacuum-packaged and aged at 4 ℃ for 19 days. Glycogen content, pH, moisture content, cooking loss, color difference, hydroxyproline content, myofibrillar protein degradation, shear force, total viable count (TVC), total volatile basic nitrogen (TVB-N), thiobar-bituric acid reactive substances (TBARS), and odor changes were measured. The results showed that during wet aging, the pH of yak meat initially decreased and then increased, reaching the ultimate pH between days 7 and 10. The a^* value exhibited an increasing trend, indicating a significant improvement in color. TVC and TVB-N values reached food safety limits on days 16 and 19, respectively. By day 10 of wet-aging, the shear force dropped below 5 kg. Volatile flavor compounds were primarily generated between days 4 and 13, and the odor intensity of nitrogen oxides, sulfides, pyrazines, terpenes, methyl compounds, and aromatic compounds increased significantly, whereas the spoilage-related metabolites were produced during 16~19 d. Considering both quality and safety, wet aging for 10 to 15 days significantly improves the edible quality of yak meat.