Effect of storage temperature on invertase, sucrose-6-phosphate synthase and UDP-glucose pyrophosphorylase activities of Japanese processing potatoes

Three cultivars (Norin-1, Toyoshiro and Snowden) of Japanese processing potatoes were stored at 5 and 12°C for 90 days. The sugar contents, and invertase, sucrose-6-phosphate synthase (SPS) and UDP-glucose pyrophosphorylase (UGPase) activities of these three cultivars were measured at intervals during storage. The aim of this study was to determine whether storage temperature affects the three enzyme levels in potatoes. The low-temperature storage (5°C) increased reducing sugar contents during storage compared with the high-temperature storage (12°C). In addition, the low-temperature storage increased the invertase and SPS activities of the three cultivars. These results suggest that invertase and SPS play an important role in the accumulation of reducing sugars in Japanese processing potatoes stored at low temperatures.