Sonication of sesame meal protein isolates modified its microstructural and functional properties

Abstract

In this study, changes in the structure and functional properties were investigated by dispersing sonicated sesame meal protein isolates (SMPI) at various pHs (pH 4, 6, and 8). SMPI, obtained through hot-water extraction from sesame meal, a food by-product, were sonicated at powers of 100, 150, and 200 W for 30 min. As a result, sonication significantly reduced the particle size of SMPI without affecting their SDS-PACE protein bands. Increasing the sonication power led to noticeable modifications in the secondary and tertiary structures of SMPI, as evidenced by a decrease in the FT-IR transmission intensity and the fluorescence intensity. Furthermore, the sonication process significantly improved the solubility and emulsifying properties of SMPI at pH values above the isoelectric point, while also increasing water and oil absorptions by 1.71- and 1.2-fold, respectively. Therefore, the sonicated SMPI (SSMPI) can be a promising candidate for reusability as a natural plant protein-based food materials, offering improved solubility and emulsifying properties.