Browning Related Factors of Fresh-cut Purple Sweet Potato under Different Storage Temperatures

In order to study the browning conditions and mechanism of fresh-cut purple sweet potato,browning degree,browning-related enzyme activity and browning substrate phenol of fresh-cut purple sweet potato were investigated under different storage temperatures(4 and 12℃). The results showed that the browning degree of fresh-cut purple sweet potato in the 12℃ storage group was significantly higher than the 4℃ storage group(P<0.05). During storage,the activity of polyphenol oxidase(PPO)and peroxidase(POD)and the content of malondialdehyde(MDA)with heavy browning were much higher. The contents of chlorogenic acid and ferulic acid in fresh cut sweet potato were significantly different under various storage temperatures for 2~8 d storage(P<0.05).Thus,the activity of browning-related enzyme,the membrane lipid peroxidation and phenolic content might be the key factors causing browning of fresh-cut purple sweet potato. Polyphenol oxidase(PPO)and peroxidase(POD)were the key enzymes that caused browning of fresh-cut purple sweet potato,and chlorogenic acid and ferulic acid were the main substrates for browning of fresh-cut purple sweet potato through correlation analysis.