Complexation of Soy Protein Microgels and Isoflavones: Implication in Modulating Bioavailability

: The soy protein aggregate particles-isoflavones complexes (SPIGs) were prepared by thermally induced protein-polyphenol co-assembly and the in vitro bioavailability of isoflavones with different soy protein matrices was evaluated. The SPIG formed by heating SPI-isoflavone dispersion at 120°C in a narrow pH range, which was defined as spherical particles with uniform size, exhibited better colloidal stability and high isoflavone binding capacity, which was higher than that of native SPI and unheated mixture. The results also showed that different pH had no significant effect on fluorescence quenching by protein-isoflavone interaction. The bioavailability of isoflavones was significantly elevated when it was encapsulated in the particles. The overall bioavailability of isoflavones maybe depends on the biotransformation of isoflavones and the production of bioactive metabolites.