Abstract: We aimed to investigate the effect of different storage temperatures on lactic acid metabolism flux in postmortem pork loin in this study. Pork samples were stored at 4 or ?1 ℃ and evaluated for the rate of change in glucose, lactic acid and NADH contents at different time points (0.5, 2, 6, 12, 24, 72, 120 and 168 h). Besides, the pattern of rigor mortis and the lactic acid metabolic pathway were analyzed in order to a central metabolic network model to determine lactic acid metabolism flux. The results showed that lactic acid metabolism flux varied with storage temperature and time. The flux of glucose entering the pentose phosphate pathway at ?1 ℃ was significantly higher than at 4 ℃, while lactic acid metabolism flux between 0.5 and 12 h at ?1 ℃ was significantly lower than at 4 ℃. The rate of decline in lactic acid flux between 24 and 168 h at ?1 ℃ was lower than at 4 ℃. This indicated that the lower the temperature was, the slower the catabolic rate was. Storage at ?1 ℃ could delay the accumulation of lactic acid and the rate of glycolysis, which was beneficial to the preservation of fresh meat. This study provides a theoretical basis for fresh meat preservation from the perspective of metabolism.

Key words: pork tenderloin, lactic acid metabolism flux, central metabolic network, glycolysis