Analyzing the effect of germination on the pasting, rheological, morphological and in- vitro antioxidant characteristics of kodo millet flour and extracts

Abstract

The present investigationwas carried out to determine the effect of germination on pasting, rheological, morphological properties of Kodo millet flour and in-vitroantioxidant characteristics of its phenolic and γ-amino butyric acid extracts. Rheological analysis depicted complex flour viscosity decreased with an improvement in shear intensity, symbolizing the shear-thinning action of flour upon germination. The frequency and temperature sweep demonstrated a decrease in visco-elasticity as a result of germination wherein, SEM revealed destruction in the continuous composite structure of starch which got entangled in dense protein matrix following germination. The in-vitroantioxidant activities such as total antioxidant capacity, DPPH*, FRAP, metal chelating ability and hydrogen peroxide scavenging activities of both the extracts increased significantly. There was a decrease in pasting properties and gelatinization behaviour whereas, visco-elastic solid behaviour changed to visco-elastic fluid. This research explores the potential of germinated Kodo millet flour for valuable bioactive compounds extraction and its utilization in product development.

Keywords: Dynamic viscosity; In-vitrohydrogen peroxide scavenging activities; Pasting profile; SEM.