Abstract
The study was dealt with the changes of chemical constituents and qualities in grape juice, apple juice and Satsuma orange juice which were irradiated at the sterilizing dose levels of gamma radiation.
Anthocyanins in grape juice were sensitive to gamma rays (Fig. 1 and Table 1) and β-carotene in irradiated Satsuma orange juice was relatively stable (Fig. 2). Irradiated apple juice became brown slightly (Fig. 3 and Table 2). The qualities of these juice products deteriorated with high doses (Table 3 and 4). The deterioration of Satsuma orange juice was slightly prevented by the addiation of propyl gallate (Table 5). Addition below 50mg% of ascorbic acid was effective to the protection of the deterioration of Satsuma orange juice and apple juice, but not above 100mg% of ascorbic acid (Table 4). The retention percent of ascorbic acid content in irradiated juice was high concentration of ascorbic acid than in low concentration of ascorbic acid (Fig. 4). There were no differences between the irradiated and unirradiated samples in titratable acidity and reducing sugar content up to the doses of 1.0-2.0 Mrad (Table 6).
