Soluble sugars from yam and changes during tuber storage

Abstract The soluble sugars (monosaccharides, disaccharides and polyols) from the leaves, stem, roots and tubers of yam ( Dioscorea ) were analysed by gas chromatography. Great quantities of d -fructose, d -glucose and polyols (2-deoxyribitol, 6-deoxysorbitol, glycerol) were found in the leaves. The stem, roots and tubers contain variable quantities of d -fructose, d -glucose, sucrose and maltose. The contents of hexoses, sucrose and maltose of stored tubers increase greatly during the rest period, but much less during the sprouting period. These results indicate that a starch-sucrose interconversion occurs during tuber storage.