Abstract: In this study, cow skim milk was chosen as raw materials, and micellar casein was obtained by ultrafiltration and spray-dried under the temperature of 130 ℃ and 150 ℃ with a spray pressure of 0.05 MPa and 0.1 MPa, respectively. The following parameters, including moisture content, particle size, bulk density, topography, solubility, intrinsic fluorescence and antioxidant properties of micellar casein, were measured. Freeze-drying samples were used as the control group. The results showed that as spray-drying temperature and pressure increased, the moisture content decreased and bulk density increased significantly with the maximum particle size of (2.16±0.29) μm under the conditions of 150 ℃-0.1 MPa. The solubility of freeze-drying samples was (87.63±0.35)% at pH7,which was similar to the solubility of spray drying samples. The freeze-drying samples had a minimum particle size of (1.31±0.02) μm, and maximum bulk density of (416.47±3.94) mg/mL. And the moisture content was similar to those of samples under 130 ℃-0.1 MPa and 150 ℃-0.05 MPa spray-drying conditions. Moreover, the solubility and intrinsic fluorescence reduced when temperature and pressure increased. However, the maximum emission wavelength and micellar topography did not alter. The best reduce power was obtained with the spray-drying samples at 130 ℃ had and ABTS free radical scavenging activities were also good, while samples obtained at 150 ℃ had the best DPPH free radical scavenging activities. Furthermore, the spray-drying micellar casein at 150 ℃ and 0.05 MPa had the best Fe2+ chelating capacity. This study could provide references for the industrial development of micellar casein and the optimization of spray-drying parameters.
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2020, Vol. 46 
