Insight into the Interaction Mechanism of Γ-Aminobutyric Acid with Soybean Protein Isolate by in Vitro, Multi-Spectral and in Silico Analyses

Abstract

In this study, the mechanism of interaction between soybean protein isolate (SPI) and γ-aminobutyric acid (GABA) was revealed and its structural and functional properties were characterized. The findings demonstrated that the incorporation of GABA induced alterations in both the secondary and tertiary structures of SPI. The interaction between GABA and SPI was found to be spontaneous and exothermic, primarily driven by hydrogen bonds and van der Waals forces. The 11S protein forms a more compact and stable molecular structure than 7S and GABA, and the introduction of GABA increases the emulsification and foaming properties of SPI, while reducing particle size and improving antioxidant properties. The results of this study elucidated the interaction mechanism between GABA and SPI, and characterized the changes in their structural and functional properties, providing a theoretical basis for improving the application of plant proteins such as SPI and the development of GABA-rich protein products.

Keywords: γ-Aminobutyric acid, soybean protein isolate, interaction mechanism