Ultra-high-pressure homogenization can modify colloidal, interfacial, and foaming properties of whey protein isolate and micellar casein dispersions differently according to the temperature condition

Abstract

We investigated how temperature condition during ultra-high-pressure homogenization (UHPH) affects the colloidal, interfacial, and foaming properties of whey protein isolate (WPI) and micellar casein (MC) using the one of UHPH device, Star Burst (SB). While UHPH treatment generally induces both mechanical force and heating under high operating pressure, we differentiated the effects of “mechanical force (below denaturation point of whey proteins)” and “combination of mechanical force and heating (above denaturation point of whey proteins)” on the proteins by controlling the protein dispersion temperature prior to the SB treatment at 240 MPa. For WPI, the combined use of mechanical force and heating induced the exposure of protein hydrophobic regions leading to a more increase in foaming ability while the sole use of mechanical force caused a more decrease in foam stability due to less adsorption efficiency at the interface. For MC, the sole effect of mechanical force strongly increased foaming ability and foam stability due to the large particle size reduction, rather than the combined use. These results suggested that SB treatment can contribute to expand the possibilities of development of new materials possessing unique physicochemical and functional properties by controlling treatment conditions.