Ability of soy protein derived amyloid fibrils to stabilize aqueous two-phase system and effect of pH on the system

Abstract

Soy protein-derived amyloid fibrils (SAFs) were utilized as a stabilizer to create stable aqueous two-phase systems (ATPS) through electrospraying. The findings of our study indicated that higher concentrations of soy protein isolate (SPI) or SAFs exhibited enhanced diffusion in the system and effective adsorption at the aqueous-aqueous interface. Consequently, ATPS containing 1% SAFs concentration demonstrated the highest stability in this approach. The superior stability can be attributed to SAFs’ high separation energy, surface activity rate, adsorption rate, and hydrophobicity compared to SPI at all concentrations. Furthermore, SAFs exhibited greater adsorption on the aqueous-aqueous interface and formed interfacial layers with higher elasticity when compared to SPI. Consequently, at a concentration of 1% SPI or SAFs, SAFs outperformed SPI in stabilizing ATPS across a range of tested pH values (2.0–9.0). These results raise the prospect of using food proteins to stabilize ATPS and facilitate the fabrication and use of protein-based materials through their biocompatible features.