Characterization of Ozonated Pearl Millet and Sorghum Starches: Pasting Profile, Functional Properties, In Vitro‐Digestibility, Molecular Interactions, and Morphology

Abstract

The present research was undertaken to study the effect of ozone treatment on isolated pearl millet starch (PMS) and sorghum starch (SS). Ozone treatment was done at various concentrations (0.06, 0.08, and 0.1L/min) for 60 minutes and their effect was evaluated on the techno‐functional properties, in vitro starch digestibility, pasting properties, morphological characteristics, X‐ray diffraction, and FTIR interactions. Functional properties such as water and oil absorption capacity and solubility increased significantly (p≤0.05) with ozone treatment. However, swelling power increased for all the ozonated starches with the rise in temperature (60o‐100°C) but a reverse trend was observed with an increase in ozone treatment. The significant increment in paste clarity (PC), gel consistency (GC), and freeze‐thawing stability (FTS) were observed for all ozone‐treated starches. Although, a reduction in vitro starch digestibility for PMS, i.e., 44.59 to 29.20 g/100 g maltose and 30.80 – 28.76 g/100 g maltose was observed. No significant effect was observed for the color values except for L* and chroma after the ozone treatment. Higher values of peak viscosity, final viscosity and lower breakdown viscosity, setback viscosity were observed on ozonation treatment (p<0.05). A‐type crystalline pattern of PMS and SS remained unaffected with ozone treatment, whereas relative crystallinity (RC) decreased with ozone dose (i.e., 23.89% for PMSO‐3 and 22.5% for SSO‐3). SEM images confirmed indentations, and enlargement of surface pores for ozonated starches were clearly observed. While FTIR spectroscopy revealed a slight decrease in the peak intensity. The ratio of absorbance (RA) at 1047/1022 cm−1 slightly reduced after ozone treatment.This article is protected by copyright. All rights reserved