Modification of whey−soybean mixed protein by sequential high-pressure homogenization and transglutaminase treatment

The main purpose of this paper was to investigate the effect of High-pressure homogenization (HPH) and sequential HPH−Transglutaminase (TGase) treatment on the structural, physicochemical, and functional characteristics of mixtures of whey protein isolate (WPI) and soy protein isolate (SPI). Compared with the untreated WPI-SPI mixture protein, the mean particle size of WPI-SPI pretreatment with HPH (H-WS) and TGase-induced H-WS were reduced by up to 62%. Circular dichroism spectroscopy, surface hydrophobicity, and intrinsic fluorescence spectroscopy showed that HPH and sequential HPH−TGase treatment on WS increased in α-helix from 9% to 13%, decreased in β-sheet from 36% to 32%. The emulsification and foaming properties of the mixed protein were increased from 59 to 79 m2/g, 120%–158% respectively.