Vol. 2, Issue 1 (2017)
Physicochemical properties and resistant starch contents of sweet potato starches from different varieties grown in Vietnam
Author(s): Luu Bui Bao Ngoc, Phan Thanh Bao Trung, Phan Ngoc Hoa, Pham Van Hung
Abstract: Sweet potato (Ipomoea batatas L.), one of the seven most important food crops worldwide, varies in shape, size and color, depending on the cultivar and the environment. In this study, the physicochemical properties and digestibility of starches from white, yellow and purple sweet potato varieties grown at different location were investigated. Starches of white, yellow and purple sweet potato had 21.6, 22.9 and 19.0% amylose content, respectively. The white sweet potato starch had polygonal shape, while the yellow and purple sweet potato starches had the round and polygonal shapes. All of sweet potato starches exhibited the A-type crystal. The paste prepared from white sweet potato starch had significantly higher pasting temperature but lower peak and final viscosity and breakdown than did other sweet potato starches. Amounts of resistant starch in the native sweet potato starches ranged in 24.0 – 25.3%, in which the purple sweet potato starch had higher amount of resistant starch than did others. As a result, the physicochemical properties and digestibility of starches were different depending on their origin and growing location even though they had similar morphology and crystalline structure.