Influence of heat-moisture treatment (HMT) on physicochemical and functional properties of starches from different Indian oat (Avena sativa L.) cultivars

Abstract

The present work was aimed to study the effect of heat-moisture treatment (HMT) at 30% moisture content and temperature of 100 °C/12 h on physicochemical and functional properties of starches from eight Indian oat cultivars. As compared to native starches, HMT starches had significantly (p < 0.05) lower amylose content (6.18-16.87%), swelling power (11.4-14.3 g/g), solubility (4.7-8.5%) and proportion of B and C type starch granules. A reduction in starch paste clarity after HMT for all the cultivar starches was observed. The results revealed lower pasting viscosities for HMT starches in comparison to native starches, thereby indicating their thermostability, and lower retrogradation. The shape of oat starch granules did not change after HMT. Both native and HMT starches showed similar A-type X-ray diffraction pattern. Among all cultivars, HMT starch from OS-7 cv. had the lowest amylose content, swelling power, solubility, B- and C-type starch granules and lower peak and breakdown viscosities. HMT starches could be used as a substitute of chemically modified starches with the advantage of being safe and a greener modification. Such modifications will enhance versatility of oat starches in development of various fabricated food products.

Keywords: Amylose; Oats; Starch.