Morphology and functionality of dry heat‐treated and oxidized quinoa starches

Abstract

Starch from quinoa was isolated by alkaline steeping method and isolated starch was modified by oxidation (@1%, 1.5% and 2% w/v active chlorine) and dry heat treatment (@ 150 and 200°C for 2 h). Native and treated starches were analyzed for physicochemical, functional and morphological characteristics. The yield of quinoa starch was 54.2% with 89.3% purity. The shape of starch granules was polygonal and irregular with an averagediameter of 1.13 μm. Starch modified by dry heat treatment enhanced solubility, water-binding capacity, and transmittance in comparison with native starch. The peak, trough and final viscosity were higher in the case of dry heat-treated starches at a lower temperature than samples of native starch as well as dry heat-treated at a higher temperature. Oxidized starches showed higher values of whiteness, breakdown and setback viscosity. Modification treatments lowered the pasting temperature and swelling power of quinoa starch. Novelty impact statement Studies on quinoa starch modification by dry heat treatment and oxidation are rare in literature and present work represents the effect of these treatments on quino starch properties. Data revealed that active chlorine concentration and heating conditions (time and temperature) during modification treatments altered quinoa starch functionality uniquely. The results offer a useful base for modification of quinoa starch by oxidation and dry heat treatment at different conditions to enhance its applicability in different industries.