Effect of high hydrostatic pressure treatment on rehydrated egg white powder

In the present study, egg white suspensions (12 w/v%) were HHP-treated at 300, 400, 450, 500, 550 and 600 MPa for 5 min. The effects of HHP treatment on the colour, rheological properties, microbiological status and digestibility of the samples was investigated. Colorimetric analysis revealed increased lightness (L*) and yellowness (b*), with decreased redness (a*), indicating enhanced visual appeal. The rheological evaluation at 500 MPa and above showed a transition from dilatant to pseudoplastic behaviour, which is favourable for food processing due to improved flow under shear stress. SDS-PAGE and in vitro digestion confirmed extensive protein denaturation and enhanced digestibility—especially the complete hydrolysis of ovotransferrin—potentially reducing allergenicity and increasing nutrient bioavailability. Microbiologically, treatments at 500–600 MPa significantly reduced mesophilic aerobic bacteria and extended shelf-life, maintaining safety over 44 days. Overall, HHP-treated egg white demonstrates promising potential as a functional ingredient in safe, nutritious, and technologically adaptable food products.