Effects of Blanching Methods on Microstructure, Enzymatic Browning and Related Quality of Peach

In this study, hot water and steam blanching were used to pretreat peach. The effects of two blanching treatments on microstructure, enzymatic browning and related qualities of peach were studied for determining the suitable blanching condition. The results showed that the effects of two treatments on peach were similar with the increase of blanching time (0~80 s) in general, the surface microstructure collapsed, PPO and POD inactivated, texture declined, the browning degree and V_C content decreased, total phenol content and antioxidant activity increased. Correlation and cluster analysis showed that PPO, POD, hardness, browning degree and V_C were extremely significant correlated. And the total phenol, DPPH· scavenging capacity and FRAP were extremely significantly correlated. The changes in physicochemical quality of hot water and steam blanching for 40 s were similar, and showed a high correlation. The quality changes of hot water and steam blanching for 60 s and 80 s were highly correlated. Overall, steam blanching maintained the better quality of peach compared with hot water treatment. When blanching for 80 s, steam blanching could effectively inactivate PPO and POD and maintain preferable tissue structure, and it showed better color quality and higher V_C content than those of hot water treatment. Hence, steam blanching for 80 s was the best blanching condition for preserved peach processing.