Characterization of Pearl Millet Nonstarchy Polysaccharides

Abstract

ABSTRACT Water‐soluble nonstarchy polysaccharides (WSNP) and water‐insoluble nonstarchy polysaccharides (WINP) of pearl millet ( Pennisetum typhoides ) were isolated, purified and characterized for carbohydrate composition. Gas‐liquid chromatographic analysis of the derived alditol acetates obtained from hydrolyzed WSNP, WINP and their respective DEAE‐cellulose fractions revealed similarities in carbohydrate content, but marked differences in distribution pattern. Rhamnose, ribose, L‐arabinose, xylose, mannose, galactose, and glucose were detected. Sepharose 4B chromatography confirmed arabinoxylan as the predominant polysaccharide, with significant amounts of arabinogalactan, and glucan noticeable in some fractions. UV spectral analysis and thin‐layer chromatography showed ferulic acid as the major phenolic compound, in addition to caffeic acid and two other unidentified phenolic acids.