تغييرات ميزان گليكو آلكالوييد كل و آلفاسولانين در سيب زميني در طول نگهداري و فرآيند حرارتي

Three potato cultivars (Solanum tuberosum L.), spring Marfona, autumn Cosima and Marfona, obtained from Isfahan Province, were stored under different conditions: 4°C, darkness; 12°C, fluorescent light; room temperature, darkness; and room temperature, daylight. Relative humidity of the above stores was 85 to 90%. Analyses were carried out to determine total glycoalkaloids, a-solanine, specific gravity and total solids, during 30 days for the spring cultivar and 90 days for the autumn cultivars in stored tubers. a-Solanine content of each cultivar was determined by HPLC, in mg per 100 g dry weight, at the beginning, the midinterval, and the end of storage periods. Also, amounts of a-solanine in autumn cultivars, which showed the highest levels after storage for sixty days, were determined before and after heat processing for frying and cooking. Data were analyzed statistically by completely randomized design with Duncanʹs multiple range test. The results revealed that the amount of a-solanine of the spring cultivar considerably increased under 12°C and flourescent light as compared with the other storage conditions. The amounts of alpha-solanine considerably increased during the storage of autumn cultivars which were stored at 12°C under flourescent light compared with those stored at room temperature and daylight, room temperature and darkness, and at 4°C and darkness, respectively. The amount of alpha-solanine decreased due to spring conditions during the storage period for cultivars stored at room temperature and darkness. In spite of the decreasing effect of peeling, before frying and after cooking, frying and cooking processes had no effect on the amount of alpha-solanine in the samples. Therefore, according to the above results, the most appropriate storage conditions to prevent increasing effect of alpha-solanine in potato tubers was 4°C in darkness.