Morphological and Physicochemical Properties of Water Chestnut Starches: a Comparative Analysis of Three Varieties

Water chestnut (Eleocharis dulcis) is widely cultivated in many countries for its edible and starchy corms. In this study, starches were separated from Guangxi biqi, Hubei biqi and Anhui biqi, and the morphological and physicochemical characteristics of the starches were systematically investigated. There were significant differences in granule size, total starch and amylose contents among starches from the three water chestnuts which present similar X-ray diffraction patterns and Fourier transform infrared spectroscopy. The starch of Guangxi biqi exhibited higher swelling power and solubility than that of Hubei biqi and Anhui biqi. Thermal and pasting properties of starch were different among the three water chestnuts. When hydrolyzed by porcine pancreatic alpha-amylase (PPA), starches from Hubei biqi and Anhui biqi had higher hydrolysis degree. The starches from the three water chestnut varieties differed significantly in morphological and physicochemical properties, and these studies may provide useful information for future exploitation and application of water chestnut starch in food and non-food industries.