Effect of Storage Temperature on Carbohydrate Metabolism and Development of Cold-Induced Sweetening in Indian Potato (Solanum TuberosumL.) Varieties

Abstract

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. Practical Applications Development of cold‐induced sweetening (CIS) is important for basic research and for potato‐processing industry. This work allowed us to group 11 Indian potato varieties into low‐sugar‐forming and high‐sugar‐forming groups, to identify varieties suitable for processing immediately after harvest or short time storage and to identify varieties with high starch content suitable for starch extraction. Hence, it provides capital information to the industry about varieties with good starch yield, which can be cold‐stored without drastic sugar increase, and to breeders for searching genes of resistance to CIS in Indian potatoes. This study also demonstrated that during CIS development in these varieties, acid invertase is the key enzyme, β‐amylase is not the main enzyme of starch degradation and there is possible significant activity of maltase in potato tubers. These observations pave the way through biotechnology work to develop new potato varieties which can cope with this postharvest problem.

Influence of storage conditions on the quality of two varieties of native potato (Solanum Tuberosum group phureja)•

“…The CUR variety shows similar tendencies to RM in its glucose content; cold-induced sweetening is comparable with studies carried out in other varieties [11,13,23,[26][27][28]. The physiological and varietal differences influence behavior and it was noted that RM shows longer resistance time to cold sweetening than CUR.…”

Cold Induced Sweetening and Antioxidant Activity of Potato Genotypes During Cold Storage

“…Observed CIS-sensitivity of Kufri Chipsona 1 in the present results could be some environmental factor as pre-harvest and post-harvest environmental factors are known to affect CIS in potato genotypes [1]. Starch content increased during storage in many genotypes, thus showing starch synthesis occurring in tubers during storage [14].…”