Isolation and partial characterization of Mexican taro (Colocasia esculenta L) starch

摘要

Taro starch was isolated from Mexican variety and its morphological, physicochemical, and molecular characteristics were evaluated. Yield starch (in dry basis) was 81 %, and this starch had low AM content (2.5%). Taro starch granules showed a mixtureof shapes with sizes between 1 and 5 urn. Taro starch presented an A-type XRD pattern with a crystallinity level of 38.26%. Solubility and water retention capacity did not change in the temperature range of 50-70°C and thereafter they increased as temperature increased too. Taro starch showed high peak viscosity due to its high AP content. The peak temperature of gelatinization of taro starch was 80.6°C with an enthalpy value of 10.6 J/g, with low retrogradation rate due to its low AM content. Weight-average molar mass (Mw) and gyration radius (Rz) of taro starch were 1.21 ± 0.8 x 109 g/mol and 424 ± 70 nm, respectively. Taro tuber could be an alternative for starch isolation with functional and physicochemical characteristics for food and nonfoodapplications.