EFFECTS OF GAMMA-IRRADIATION AND TEMPERATURE ON SUGAR AND VITAMIN-C CHANGES IN 5 INDIAN POTATO CULTIVARS DURING STORAGE

The changes in sugar and vitamin C content of five potato cultivars subjected to gamma irradiation (100 Gy) to cause sprout inhibition were compared with nonirradiated control tubers during storage at 27-32°C (ambient temperature) and 15°C, and also with control tubers stored at 2-4°C-the commercial cold storage temperature. Reducing and nonreducing sugars increased during extended storage at all temperatures, the maximum increase occurring at 2-4°C. The proportion of nonreducing sugars was higher at 27-32°C, whereas at 2-4°C reducing sugars formed the greater proportion. Irradiation did not influence the pattern of sugar accumulation. Irradiated potatoes stored at 15°C for 6 months had lower sugar levels than control tubers stored at 2-4°C. During the first 2 months vitamin C levels were lower in irradiated potatoes stored at 15°C than in the controls stored at 2-4°C, but were subsequently higher. The suitability of tubers for processing into crisps and french fries was not affected by irradiation and storage at 15°C for 6 months. © 1990.