Impact of high-power sonication on yield, molecular structure, and functional properties of soy protein isolate

This study reports the influence of high-power sonication (HPS) pre-treatment on protein yield, molecular structure, and functional properties. HPS energy densities (0-720 J/mL) were applied to soybean flour and flakes prior to protein extraction at pH 8.5 for 15 or 30 min at 60 degrees C, and 5 min at room temperature. The isolates were prepared by precipitating at pH 4.5 and had > 90% protein. HPS of 720 J/mL to flakes substrates extracted 80% protein without any incubation and 85% with 15 min incubation when no-sonication control showed an extraction of 71%. FTIR showed some aggregation and intrinsic fluorescence and free SH content showed pronounced effects on isolates from flour. HPS increased the surface hydrophobicity, reduced solubility, and enhanced the emulsification and foaming properties for a few treatments. Therefore, incubation duration changed structural and functional properties more prominently than did HPS in the isolates from flour than flakes.

Automated summary

This study investigates the effects of high-power sonication on protein yield, molecular structure, and functional properties. The results show that the impact of sonication on protein extraction depends on the incubation duration and the nature of the substrate.