Variability of non-starch polysaccharides in taro

Abstract

Although cultivated primarily for their starch content, the nutritional and functional properties of taro [Colocasia esculenta (L.) Schott] corms can be modified by the presence of non-starch polysaccharides. Twelve varieties from the Philippines, 14 varieties from the Solomon Islands, and 3 varieties from Hong Kong were assessed for their polysaccharide content other than starch. Several non-starch polysaccharides were present and a major fraction was the water-soluble arabinogalactan proteoglycan. Monosaccharide analysis of the whole flour from the corms also indicated the presence of xylose and mannose indicative of the presence of xyloglucan and glucomannans. High levels of arabinogalactan contributed to the mucilaginous character of taro corms. The functional consequences of the xyloglucan and glucomannan fractions were not established and are currently under investigation.