Investigating the effect of natural fermentation in modifying the physico‐functional, structural and thermal characteristics of pearl and finger millet starch

Abstract

BackgroundIn recent years, millets are often considered an emerging crop for sustainable agriculture. Therefore, millets can be exploited as an alternative source of starch which has many applications ranging from food, packaging, bioplastics, and others. However, starch is seldom used in its native form and is more often modified to enhance its functional properties. In literature, many traditional millet‐based food recipes often incorporate a fermentation step before cooking. Therefore, using this traditional knowledge fermentation has been explored as a potential method for modifying millet starch.ResultsPearl millet (PM) and finger millet (FM) flour were allowed to naturally ferment for 24‐hour (h) followed by starch extraction. Compared to native (N) starch water/oil holding capacity and least gelation concentration of fermented (F) starch decreased with no significant change in swelling power. The solubility, paste clarity and invitro digestibility of starch were significantly affected by fermentation. XRD data indicates that after fermentation, crystallinity increased while the A‐type crystalline structure remained intact. FTIR spectra showed no deletion or addition of any new functional groups. Thermal characterization by Differential Scanning calorimeter (DSC) showed that the enthalpy of gelatinization of PM starch decreased while that of FM starch increased after fermentation.ConclusionThe results indicate that 24‐hour natural fermentation had a significant impact of functional properties of starch without altering the structural architecture of starch granules. Therefore, fermentation can be further explored as a low‐cost alternative for starch modification.This article is protected by copyright. All rights reserved.