Effect of Harvest Time and Storage at Low Temperature on Inulin and Potassium Content in Tubers of Jerusalem Artichoke

Abstract

The Jerusalem artichoke (Helianthus tuberosus L.) is a root vegetable rich in inulin, which has been reported to suppress elevated blood glucose levels. This study aimed to investigate changes in inulin and potassium contents of Jerusalem artichoke harvested in different periods. Furthermore, appropriate harvesting periods that result in tubers with high inulin and low potassium contents were determined. The results showed that the inulin content and its degree of polymerization gradually decreased from November to February, whereas the potassium content increased until December in the tubers. These results indicate that the optimal harvesting period for Jerusalem artichoke may be early November. Studies on the storage methods for tubers indicated that the increase in the potassium content observed in the field study can be suppressed under low-temperature storage. Therefore, we conclude that storage at low temperatures is effective for controlling the potassium content of tubers.