Study On The Controlling Technology Of Browning In Apple Juice Process

The Controlling Technology of browning was studied in apple juice process according to the pratice of juice production .The main conclusions were made as below :1.The different kinds of apples have different effects on the color value. Three kind of apple juice were analyzed by varieties of apple and maturity of apple. The lower the maturity is, the lower the color value is. The main factors of variety on the browning degree were the values of xiao guoguang > fuji > golden delicious. The interaction of varetietes of apple and maturity of apple can also reduce the browning. The phenolic compounds (catechin ,eptcatechin, chtogein acid, phloridzin, P -coumaric, ferulic, caffeic acid) can be found in the fuji apples.2.The formation of browning in apple juice was reduced by asepic, enzymolysis and adsorption .The contents of epicatechin, chlorogenic acid, caffeic acid , phloridzin and small phenolics ,browning-active polyphenolics were increasd by asepic,but no effect by adsorption. The content of chlorogenic acid was reduced by adsorption for 4 hours.3.The parameters of reducing the browning in apple juice were optimized. Effects of enzymatic time, adsorption time on the absorption at the optical wave of 420nm and the contents of condensed tannin were studied. The results of showed that the optimal parameters were: enzymatic time 75 min, adsorption time 7 hours.4.The used of active carbon in the T420 of apple juice was studied to enhance the T420 and control the browning in apple juice. Taking the diameters and the amount of the active carbon as the factors, the reduction of browning-active polyphenol and the enhancement of T420 were analyzed. The result is, the active carbon that passed 200mu behaved the worst in between of 200mu, 160mu, 120mu and 80mu. There are no differences between 160mu, 120mu and 80mu. The contents of browning-active polyphenolics were no effect by different diameters of active carbon.5.At high temperature, the adsorption of browning of the apple juice was increased. But the browing-active polyphebolics had no change.