Development of soy protein isolate-soybean oil emulsion-aggregated gels with enhanced elasticity and structural stability using vacuum-autoclave treatment.

This study investigated the structural and functional characteristics of soy protein isolate (SPI)-based emulsion-aggregated gels produced at different SPI-to-oil ratios with or without vacuum-assisted (VA) treatment. VA treatment markedly enhanced gel cohesion, reduced porosity, and produced denser, smoother microstructures, as confirmed by SEM analysis. Optimal formulations (S3O7 and S4O6) exhibited balanced textural properties, superior freeze-thaw stability, and higher absolute zeta potentials, indicating improved colloidal and structural stability. Protein solubility analysis revealed increased hydrogen bonding, disulfide crosslinking, and hydrophobic interactions after VA treatment, supporting a more cohesive and ordered protein network. Compared to conventional tofu, the developed gels demonstrated improved structural stability, enhanced water retention, and greater protein density. These findings highlight vacuum-assisted emulsion aggregation as an effective strategy for tailoring microstructure and stability in protein-based gel systems. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-025-02048-x.