Chemical composition and storability of Jerusalem artichoke tubers

Five different Jerusalem artichoke cultivars were investigated to compare their nutritional value. Investigations were carried out on samples harvested in December 2004 and stored until the end of March 2005 under natural climate in prism, in cold store and also after over-wintering in the soil. Investigations were repeated in 2005 and 2006. According to the results of storage outdoors in prism and in cold store, the total- and soluble solid content, the total carbohydrate and inulin content (w/w) did not change significantly as a function of storage time. Changes in sucrose- and reducing sugar content and that of glucose/fructose ratio were also insignificant. There was no significant difference in the ratio of carbohydrates of the tubers stored tinder those two above-mentioned conditions, however, there was a significant difference in the carbohydrate composition of the tubers harvested in winter or in spring. Compared to the majority of vegetables, the main nutrient of Jerusalem artichoke tubers is inulin, instead of starch. Total carbohydrate content of the tubers is divided into 80-90% inulin, 7-14% sucrose and 3-6% reducing sugars, on average. Because of its high average yield and outstanding inulin content, this is a plant of great interest as raw material for inulin and fructose processing, as well. The cultivar Cegledi is, first of all, suggested for industrial processing. The present research data verified its outstanding inulin content and a high fructose/glucose ratio, too.