Inulin content of Jerusalem artichoke (Helianthus tuberosus L.) tubers stored at 5 oC in a refrigerator for different durations

Abstract

Jerusalem artichoke is a perennial crop, but it is grown as an annual crop for its inulin containing tubers. Various factors affect inulin content, in which storage duration is one of the significant causes. Therefore, the effect of different storage durations on inulin content of Jerusalem artichoke was investigated in this study. Four Jerusalem artichoke varieties were assigned as factor A, and six durations of storage at 5 oC were assigned as factor B. The 24 treatment combinations of a 4×6 factorial were arranged in a completely randomized design with four replications. After harvest, the tubers were cleaned and stored at 5 oC for five months. Inulin content was analyzed consecutively at 0, 1, 2, 3, 4 and 5 months after storage. Times of storage and varieties were significantly different (P<0.01) for inulin content. Stored tubers had inulin contents ranging from 35.9 to 43.7 % compared to 47.8 % of freshly-harvested tubers. The lowest inulin content was found after 2 months of storage. JA 89 had the highest inulin content (47.80%), whereas CN52867 had the lowest inulin content (35.85%). Regression analysis showed small and insignificant effect of storage time on inulin content, and the results are discussed. The results will be useful for consumers and industries for their concern on storage loss of inulin content after storage