Abstract:

The effect of high pressure homogenization and heat treatment on protein solubility in soymilk and the
mechanism involved were studied. High pressure homogenization increased the protein solubility in raw soymilk and
reduced the viscosity and particle size. This effect was enhanced when used in conjunction with heat treatment. TEM
observation demonstrated that a combination of thermal treatment with high-pressure homogenization increased the
dispersion and uniformity of soymilk particles and decreased the particle size, improving hydration properties of soymilk and
thereby increasing the solubility of the soy proteins. Internal fluorescence analysis showed that homogenization and heating
changed the conformation of proteins in soymilk, improved the polarity of the microenvironment around tryptophan residues
and enhanced hydration of protein molecules. SDS-PAGE results showed that both treatments could induced and degrade
protein aggregates and simultaneously improve the solubility of soymilk proteins.

Key words: high pressure homogenization, heating, soy protein, solubility, soymilk, mechanism