Effect of Coupled Pulping and Enzyme Inactivation by Steamon the Quality of Fresh Apple Juice

Abstract:

In order to investigate the effect of steam treatment on browning and quality of fresh apple juice，a self-designed equipment of coupling pulping and enzyme inactivation by steam was set up. By a series of experiments we found that if the ending temperature of pulp was above of 80 ℃，the color of apple juice was bright stability，the activity of PPO was almost lost and the enzyme browning was inhibited effectively. The chemical properties，antioxidant activity，volatile flavor compounds of three kinds of apple juice pulped in steam with the ending temperature 93、83、25 ℃ respectively were analyzed and compared. As a result，the physical and chemical properties of the juice was improved，and the antioxidant activity was preserved greatly，as well as the volatile flavor compounds of apple juice was also changed at a certain extent.