γ-Aminobutyric acid and fat alter soymilk gel properties and functionality via protein remodeling

Legumes can be transformed into nutritionally rich, plant-based fermented milk with multiple functional properties through lactic acid bacteria fermentation. This study aims to investigate the mechanisms by which γ-aminobutyric acid (GABA) and fat influence the gel network structure and functional characteristics of fermented soymilk. The results indicate that GABA can bind to soybean proteins, promoting the formation of a denser gel network, thereby improving product texture. An appropriate amount of fat facilitates flavour release, but excessive fat disrupts the protein network structure and reduces gel strength. Metabolomic analysis reveals that GABA primarily regulates amino acid metabolism pathways, while fat significantly influences lipid metabolism pathways. Correlation analysis further demonstrates that changes in protein conformation are a key intrinsic factor affecting gel properties and functional characteristics. This study is the first to elucidate the mechanisms of GABA and fat in the construction of fermented soymilk gel and metabolic regulation, providing a theoretical basis and technical support for the development of fermented soymilk products with excellent texture and nutritional richness.