Functionality of milk protein concentrate: Effect of spray drying temperature

Abstract

This study investigated the effect of spray-drying conditions on the resulting functionality of milk protein concentrate (MPC), utilizing specially produced mono-dispersed MPC particles. The particles were generated from a pilot microfluidic spray dryer at selected inlet air temperatures (77°C, 107°C, 155°C and 178°C). The solubility and extent of protein denaturation were characterized using focused beam reflectance measurement and polyacrylamide gel electrophoresis. Due to the controlled drying conditions and well-defined properties of the particles, a direct relationship between spray drying temperatures and the resultant particle functionality could be identified. The particle morphologies obtained from lower inlet air temperature appeared spherical whereas the one from higher inlet air temperature appeared deflated. The FBRM results indicated that the solubility of MPC particles deteriorated with increasing inlet air temperature with increasing protein denaturation. SDS-PAGE results suggested that the insoluble material were primarily casein rather than heat sensitive whey protein. These findings could be used to establish a better understanding of the relationship between drying conditions and MPC microstructures, and the corresponding influence on the functionality for non-traditional powder types.