Effect of Processing on the Physico‐Chemical Characteristics of Quinoa Flour (Chenopodium quinoa, Willd)

Abstract

The nature and extent of the modification of starch in quinoa, caused by various processes like cooking and autoclaving of the seeds, drum drying of the flour and extrusion of the grits was investigated by measuring the physico‐chemical properties ‐ the water absorption, water solubility, swelling power, viscosity and degree of gelatinisation ‐ of the processed samples. Autoclaved samples showed the lowest degree of gelatinisation (32.5% by DSC) of the starch, while the degree of gelatinisation of the precooked/drum dried samples was found to be 97.4% by DSC method. Higher polymer degradation was observed in cooked samples than in autoclaved samples as seen in the gel chromatographic separation. The water solubility in cooked samples (5.44 to 15.58) and in autoclaved samples (7.02 to 9.64) increased with the process time. In the extrusion process, the moisture content as well as the compression ratio was found to affect the degree of starch modification significantly (p <0.01). Copyright © 1993 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim