Physicochemical properties of starch extracted from <i>Colocasia esculenta</i> (L.) Schott (Bun‐long taro) grown in Hunan, China

Abstract

Taro ( Colocasia esculenta (L.) Schott) starch was extracted from the corms of Bun‐long taro cultivated in Hunan, China, and its physicochemical properties were determined and compared with those of potato and sweet potato starches. Bun‐long taro starch had an irregular, polygonal shape, and grains were small in size: the surface‐average granule diameter ranged from 1.3 to 2.2 µm. Amylose content in Bun‐long taro starch was 8.4 ± 0.2%, determined by dual‐wavelength colorimetry, and the starch had an A‐type XRD pattern. The onset temperature ( T o ), peak temperature ( T p ), and completion temperature of gelatinization ( T c ) associated with Bun‐long taro starch were 73.6, 80.3, and 88.3°C, respectively, determined by DSC. According to the Brabender amylograph paste viscosity analysis, the viscosity of Bun‐long taro starch started increasing at 77°C, which was higher than the temperatures at which the viscosities of potato starch and sweet potato starch started increasing.