Changes in sugar contents and invertase activity during low temperature storage of various chipping potato cultivars

Abstract

Storage of tubers is vital for uninterrupted supply to potato chips/fries industry. Cold storage is preferred to maintain tuber quality. However, prolonged storage at low temperature results in cold induced sweetening (CIS) leading to sugar accumulation and browning of chips. Slowing down the CIS is of economic importance for potato industry. Screening of potatoes after cold storage for low sugar and invertase activity with exploration of best frying color was the aim of current study. Reducing sugars (RS), invertase activity and chips color were estimated after subjecting the tubers at 3°C and 7°C storage. Analytical techniques were adopted for quantification of RS and invertase activity while nine-point Hedonic scale was used for chips color evaluation. Highest invertase activity with maximum RS (mg 100-1g) and dark brown chips were observed in Kuroda following the Santé (247.83), Asterix (216.73), Crozo (193.42), Hermes (171.57) and Lady Rosetta (134.07) after storage at 3°C. Low RS were found in tubers stored at 7°C with good frying color in Lady Rosetta (98.23) followed by Hermes (104.31) and Crozo (113.27). Conclusively storage temperatures have significant effect on quality of tubers in which 7°C proved best with less RS and invertase activity having good frying color.