In this study, proteins were extracted from sesame and perilla meals (agricultural by-products) by using hot-water defatting and acid precipitation, and their functional properties were compared with those of a commercial soy protein isolate (SPI). According to the SDS-PAGE results, the sesame meal protein extract (SMPE) exhibited a higher content of hydrophobic amino acids than the perilla meal protein extract (PMPE), alongside a relatively lower intensity of the 7S globulin band. SMPE showed 1.41-fold higher solubility than SPI at pH 10 and 1.72- and 1.66-fold higher emulsifying activity indices (EAIs) at pH 8 and 10, respectively. PMPE exhibited similar trends in solubility and EAI as SPI at the corresponding pH values. However, the emulsifying stability indices of SMPE and PMPE were lower than that of SPI. In particular, the fat absorption capacity of SMPE was significantly higher than those of SPI and PMPE, likely because of its higher content of hydrophobic or nonpolar amino acid residues. These results suggest that SMPE and PMPE are promising alternative protein sources for food applications and may promote value-added utilization of plant-derived by-products in the food industry.
In this study, conjugates were prepared via dry heat-induced glycosylation with maltodextrin (MD) to enhance the functional properties of sesame meal protein extract (SMPE). With the progress of conjugation, the specific protein bands of SMPE decreased and new bands appeared in the higher molecular weight range (approximately 170 kDa). The FT-IR spectra confirmed the structural modifications resulting from Maillard reaction-driven covalent bonding between SMPE and MD. The solubility and emulsifying properties—emulsifying activity index (EAI) and emulsifying stability index (ESI)—of the conjugates showed little variation with dry-heat treatment time, but they were significantly influenced by the dextrose equivalent (DE) of MD. Solubility was highest when SMPE was conjugated with MD of DE 4–7 at both 12 h (19.38%) and 24 h (20.54%) and decreased as DE increased. Notably, the three-way ANOVA results showed that the emulsifying properties improved significantly with higher DE of MD. The EAI and ESI of SMPE conjugated with MD of DE 16.5–19.5 increased by 1.52- and 1.41-fold, respectively, when compared with the control SMPE. These findings suggest that the SMPE-MD conjugates have promising potential for applications in food systems that require enhanced emulsifying properties.