Effect of storage temperature on carbohydrate metabolism and development of cold-induced sweetening in Indian potato ( Solanum Tuberosum L.) varieties

This study investigated the changes in carbohydrate metabolism in tubers of 11 Indian potato varieties stored at room temperature, 15C and 4C for 150 days to understand the development of cold-induced sweetening (CIS). Low-temperature storage negligibly influenced starch and maltose contents of the tubers but induced a significant increase of reducing sugars, total soluble sugars, fructose, glucose and hexoses : sucrose ratio, and a decrease of sucrose content was noticeable at 4C. A strong positive correlation was found between reducing sugars and total soluble sugars, and between fructose and glucose. The activity of β-amylase was considerably increased by storage at low temperature, and it weakly correlated with starch content. Also, the absence of maltose accumulation with increased β-amylase activity was observed. Acid invertase activity drastically rose at low temperature and strongly paralleled reducing sugars, glucose, fructose and hexose : sucrose ratio. The K. Jyoti variety was designated as CIS-tolerant and the K. Badshah variety as CIS-susceptible