Nutritional quality of irradiated orange juice

Single-strength orange juice was exposed to 0, 0.89, 2.24, 4.23 and 8.71 kGy gamma radiation at 5C, and then stored at 23C for 6 days and 7C for 21 days. Conversion of ascorbic acid (AA) to dehydroascorbic acid (DHA), and loss of AA, total AA (TAA=AA plus DHA) and total antioxidants increased with radiation dose. Rate of TAA loss due to irradiation was much less than that of AA loss. Compared to nonirradiated juice (0 k-Gy), juice irradiated at 2.24 kGy or less had similar rates of AA and TAA loss during storage while juice irradiated at 4.23 and 8.71 kGy had higher rates of AA and TAA loss. Loss of total antioxidants in irradiated orange juice appeared to result from loss of AA.