Influence of novel food processing technologies on the rheological and thermophysical properties of whey proteins

The effects of three emerging technologies: high pressure (HP: 500 MPa, 10 min), ultrasound (US: 20 kHz, 15 min) and tribomechanical activation (TA: 40000 rpm) on flowing behaviour and thermophysical properties of whey protein isolate (WPI) and whey protein concentrate (WPC) were investigated. HP and US were carried out on 10% (w/w) model dispersions while for TA samples were in powdered form. Pressurization caused significant decrease (p < 0.05) in solubility of WPC and WPI, while both samples treated with US and TA exhibited significantly better solubility (p < 0.05) compared to control. Apparent viscosity data described with power law equation (r2 = 0.97–0.99) significantly increased (p < 0.05) after all treatments while HP caused the most intensive changes in rheological behaviour. The flow behaviour of WPC and WPI was observed to be shear-thickenning after all treatments. Decrease of initial freezing point, accompanied with increase of specific enthalphy were remarkable for all samples. It could be concluded that high pressure considerably affected the examined properties compared to other two treatments.