Study On The Browning Inhibition Technology For Fresh-cut Root And Tuber Vegetables

Owing to the freshness, cleanness and convenience, fresh-cut fruits and vegetables have been developed very fast in developed countries. Although fresh-cut fruits and vegetables start relatively late in China and have large gap compared to developed countries, the products will get a rapid progress with economic development and changes of consumption habit. Effects of different methods on the browning control of fresh-cut Great burdock, Jerusalem artichoke and Lotus root were investigated, the results are as follows:1. Ethanol vapor treatment could retard the browning of some fruits and vegetables and it was related with varieties of materials and concentrations of ethanol. Ethanol vapor treatment could retard the browning of yams, great burdocks and Jerusalem artichokes for 12 to 15 days, 3 to 4 days and 9 to 10 days during storage (4～5℃). 450μL/L was the best concentration of ethanol to inhibit the browning of fresh-cut Jerusalem artichokes.2. PAL was possibly the major enzyme responsible for the browning of fresh-cut Jerusalem artichokes. Retarding the browning of fresh-cut Jerusalem artichokes and inhibition of PAL activities was possibly related. Ethanol vapor treatment had inhibitory effect on POD and PPO activities, and the higher concentration of ethanol the lower activity of the enzymes.3. According to the changes of whiteness, crude fiber content and rot rate, it came to the conclusion that Jinan dawolong was the optimal variety of the three varieties and selected as the fresh-cut material. Heat shock treatment after cutting (50℃hot water treatment for 4 min, 6min, 8min, 10min) reduced the browing degree of fresh-cut lotus root efficiently and this had relationship with inhibition of the increase in PPO activity. Heat shock treatment before cutting (50℃hot water treatment for 15 min, 20min, 25min), ethanol solution and Vc-Ca had no significant effect.4. Vacuum package companied with 1.5%Citric acid +0.5% Ascorbic acid + 0.5% CaCl2 could efficiently inhibit the browning of fresh-cut great burdocks, and the color, flavor and texture of products kept good after storage for 30 days at 0～3℃.