Effect of annealing and ultrasound treatments on physicochemical, functional, thermal, and structural properties of proso millet starch

Abstract

Abstract Proso millet (Panicum miliaceum L.) starch was modified using annealing and ultrasound treatments, and their effect on starch's physicochemical, functional, thermal, and structural properties was analyzed. The modification process significantly enhanced the amylose content; the highest value of 22.38% was observed in ultrasound-modified starch (US). The functional properties were enhanced by modification, where the US provides maximum solubility and swelling power at all temperatures (70 ⁰C, 80 ⁰C, and 90 ⁰C). The gel obtained from the US provided better characteristics like high consistency and cohesiveness. The gelatinization temperature of modified starches was significantly reduced by the disintegration of starch granules confirmed by the SEM images. The least gelatinization temperature of 69.82 ℃ and change in enthalpy of 2.31 J/g was observed in the ultrasound-modified proso millet starch. As a result of this study, it was observed that the annealing and ultrasound treatments significantly alter the functionality of the proso millet starch, and ultrasound modification might be an appropriate technique to enhance the application of starch in food industries. Graphical Abstract

Keywords

• Proso millet starch
• Annealing
• Ultrasound
• Starch modification
• Functional properties
• Scanning electron microscopy