Functionality of milk protein concentrate: Effect of spray drying temperature

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.

Graphical abstractSEM images of relatively uniform Milk Protein Concentrate particles with distinct morphologies generated using a pilot scale microfluidic spray dryer at different inlet air temperatures of (a) 77 °C; (b) 178 °C.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Effects of spray drying conditions on functionality of Milk Protein Concentrate (MPC). ► Generation of monodisperse particles eliminates size variation and uneven drying conditions. ► Drying directly affects changes in particle morphology, protein denaturation and functionality. ► Effective drying at low temperature with proper contacts between liquid droplets and drying air.