Effects of Maturation after Slaughter on Physicochemical Properties and Proteins Expression of Goats Meat

In order to investigate the physical and chemical properties of goats during maturation process within 48 h after death, longissimus dorsi muscle of goats at 0, 12, 24 and 48 h after slaughter was taken respectively. The TPA, pH, water retention rate, sarcoplasmic protein solubility and differential expression proteins (DEPs) level were measured respectively to study the change of meat quality at different maturation stages. The results showed as follows: With the extension of post-mortem time point, the pH of goats meat decreased significantly within 48 h (P<0.05), and ranged from 6.5 to 5.5. Drip loss significantly increased from 0 to 24 h post-mortem (P<0.05), and the cooking loss significantly decreased after 12 h post-mortem (P<0.05). Redness (a^* value) and brightness (L^* value) were significantly increased (P<0.05) in the first 24 h of goat meat maturation, but there was no significant difference in yellowness (b^* value) (P>0.05). Within 12 h after slaughter, the solubility of myofibrillar proteins in goat meat samples decreased significantly (P<0.05), and then increased gradually (P<0.05), solubility of sarcoplasmic fibers protein increased gradually with the prolongation of post-slaughter time (P<0.05). The glycogen content of Xinjiang goats within 48 h after slaughter significantly decreased (P<0.05). Compared with 0 h, there were 13 DEPs in the 12 h group, 26 DEPs in the 24 h group, and 69 DEPs in the 48 h group. The expression of enzymes related to energy metabolism was up-regulated from 0 to 48 h, and the expression of proteins related to lamb odor was up-regulated from 24 to 48 h. The tenderness, color and taste of Xinjiang goat meat were superior during the maturation period of 24~48 h after slaughter, the processing and storage during this period could provide basic guarantee for the quality of Xinjiang goats.