Purple and beige-fleshed sweet potato starches modified by autoclaving

Abstract

In this study, the effects on the morphological, functional, pasting, and thermal properties of purple (PSP) and beige (BSP)-fleshed sweet potato starches, resulting from the application of the physical autoclave method (at 121 °C and 1.1 Kgf cm−2) under different moisture conditions and exposure times, are evaluated. The micrograph shows cracks on the surfaces of the starch granules exposed for 15 and 60 min with 30% moisture. The maximum points on the response surface graphs show that the treatment increases the initial and peak gelatinization temperatures, as well as the pasting temperature and the water absorption and solubility values. In relation to the pasting properties, there is a reduction in both the final viscosity and setback values of the autoclaved starches. Thus, the method proves to be useful for the modification of these native starches and for future research with their applications in different processed foods.