The functionality of micellar casein produced from retentate caprine milk treated by HP

The effect of high pressure (HP) treatment on the physicochemical, structural, and rheological characteristics of microfiltration retentate (MFR) caprine milk prior to spray drying was investigated. In addition, the functional and microstructure properties of micellar casein concentrate (MCC) were determined. Microfiltered/diafiltered milk protein retentates was treated at (25 ± 2) °C for 15 min with a different levels of pressure (100–500 MPa), and then spray dried. The results showed that the turbidity and casein size decreased significantly while pH, soluble calcium and phosphorus significantly increased with an increase in pressure level. Further, the structural characteristics of MFR for all samples were studied. There was an increase in hydrophobicity of HP-treated samples compared with the untreated. In contrast, the G'max and yield stress values of the HP-treated MFR gels decreased. The MFR sample treated with HP at 100 MPa had the highest average of the G'max (99.75 Pa), and the lowest value of rennet coagulation time (25.9 min). Moreover, the solubility, emulsifying and foamability of MCC samples increased significantly with HP-treated samples compared to control. Maximum percentages of solubility (80.3), foam capacity (47) and foam stability (79.8) were observed at MCC-400 MPa. However, MCC-400 MPa sample showed the lowest average turbiscan stability index at 1 and 24 h (4.9 and 7.3, respectively). Thus, HP pre-treatment could be used as a good alternative technology to promote MCC products' application in the food industry. •HP-treatment of MFRs decreased turbidity and size while increased pH, soluble Ca and P.•The G'max and yield stress values of the gels made from MFR treated by HP decreased.•HP have improved the properties of MCC powders, as solubility, foamability and emulsification.•HP a good alternative technology to expand the application of food protein industry.