Abstract:

The enzymatic removal of the endocarp from sweet orange (Citrus sinensis) segment using viscozyme was
optimized in this study. Meanwhile, the effects of the enzymatic method and the traditional acid-alkali method for
endocarp removal on orange cystic quality were compared. R esults showed that the optimal enzymatic conditions were as
follows: viscozyme concentration, 0.35%; temperature, 50 ℃ and hydrolysis time, 40 min. After acid-alkali treatment, the
preservation rates of vitamin C , total acid, reducing sugar, total sugar and aroma components in cystic juice were respectively
78.71%, 56.01%, 75.17%, 79.45% and 82.72%. In contrast, the preservation rate of main nutritional components in cystic
juice was more than 96% and the preservation rate of aroma components was increased by 15.46%. We conclude that the
enzymatic method is superior to the acid-alkali method with respect to all the indicators.

Key words: Citrus sinensis, endocarp removal, enzymatic method, acid-alkali method