Processing quality of low and high sugar potato cultivars as influenced by storage temperatures*

Five low sugar exotic cultures and three high sugar Indian varieties grown under short day conditions were evaluated for chip colour and processing related characteristics before and after storage in a refrigerated store (3–4°C, RH 90–95%) for 28 days and in a high temperature farm store (Max temp 24–38°C, Min temp 16–26°C RH 30–75%) up to 75 days. Before storage, fresh fried chips prepared from exotic cultivars were far superior in colour in comparison to Indian varieties. The dry matter content of exotic cultivars was also higher than the Indian cultivars, while free amino acids and total phenols were significantly lower in the exotic cultivars at the time of storage. However, chip colour score and the contents of reducing sugars, sucrose and free amilloacids increased in both the exotic and Indian cultivars after 28 days of refrigerated storage.

High temperature storage up to 75 days was found to be suitable for producing chips of acceptable light colour from all the exotic cultivars, while only one Indian variety, Kufri Lauvkar, performed well under these conditions. The average contents of reducing sugars, free amino acids and total phenols dropped by approx. 50%, 8% and 25% respectively, while that of sucrose increased by 13% after 75 days of farm storage.