Effect of growing location on the processing quality of two potato cultivars stored at low temperature

Tubers of two potato cultivars viz., Kufri Jyoti and Kufri Sindhuri grown at three locations viz., Jalandhar, Modipuram and Patna were stored at 4° and 10°C with and without CIPC (isopropyl N-(3-chlorophenyl) carbamate) treatment for 145 days and changes in weight loss, dry matter content, reducing sugars, sucrose, chip colour and phenols were determined. Weight loss was 15.6% after 145 days of storage (DOS) at 10°C without CIPC treatment and it reduced to 4.2% with CIPC treatment. Potatoes grown at Patna had higher dry matter and lower sugar content while potatoes grown at Jalandhar had lower dry matter and higher sugar content. Potatoes grown at Modipuram showed intermediate values. Although the reducing sugar content before storage was lower in potatoes grown at Patna, there was no significant difference in sugar accumulation during storage except at 115 DOS. The chip colour was unacceptable in both the cultivars. There was no clear trend during storage in phenol content of potatoes grown at different locations. The results revealed that reducing sugar content before storage was related to the reducing sugar content of tubers up to 55 days of storage at 10°C with CIPC treatment but no relationship was observed when stored for a longer time, indicating that reducing sugar content at harvest is not a reliable basis for predicting sugar content after prolonged storage. In unpeeled tuber, the maximum CIPC residue level was 4.5 mg/kg f.w., which was within the acceptable limit.