Seasonal changes in the carbohydrates of the Jerusalem artichoke tuber

Abstract
Analyses of dry matter and of ketose and combined reducing substances in aqueous extracts were made on tubers of the Jerusalem artichoke for 12 mos. The change in carbohydrate composition during the winter months was confirmed. The positive increase in optical rotation was correlated with an increase in carbohydrate components of lower molecular wt. estimated by paper-partition chromatography. It is suggested that a slow conversion of combined fructose to glucose take place, and from the glucose more sucrose is formed. By trans-fructosidation, a redistribution of fructose residue occurs, increasing the amts. of substances of small molecular size.