Effects of processing conditions of the green-leafy vegetable juice enriched with selenium on its quality stability

摘要

The authors used selenium-enriched vegetables as test materials during research on juice production. The purpose of this study is to provide a basis for developing a practical processing technology. The changing regularity of two quality attributes on three Se-enriched green-leafy vegetable juices was studied during juice making. The effects of processing conditions on chlorophyll contents, total Se content and organic Se percentage were measured. The difference of enriching with zinc between pre-harvest and post-harvest, chlorophyll preservation and separation during storage of combined juices have been discussed. The results show that the effect of blanching on total selenium content is far more severe than the effect of sterilization. However, the effect of the process of sterilization on organic selenium percentage is far more severe than the effect of blanching. The range of ZnCl_2 content that was sprayed by the process of agronomic Zn-enrichment before production is 1200-1400μg/ml. By means of color preservation, chlorophyll in combined vegetable juices can be preserved almost the same as that of single vegetable juice. Alginate-Na has an effective action in preventing sedimentation in combined vegetable juice.