Improved rehydration characteristic of micellar casein powder by electrostatic spray drying

Micellar casein (MC), a key protein derived from milk, is extensively utilized in the food sector. Nevertheless, the practical application of MC powder is constrained by its inadequate rehydration performance. This study investigated the effect of electrostatic spray drying (ESD) on the rehydration properties of MC powder, as well as compared its performance with those of freeze drying (FD) and spray drying (SD). ESD powder showed a quick dissolution and dissolved nearly 96% within 16 h, showing a higher stability of MC solution without sediment. In contrast, FD and SD powders showed lower solubility (85% and 75%). ESD-produced MC powder exhibited higher κ-casein and faster water erosion, leading to rapid size reduction (< 200 nm) upon rehydration minimal hydrophobic exposure, and improved hydration efficiency. This study demonstrates that ESD can effectively improve the hydration properties of MC, establishing a theoretical foundation for industrial manufacturing processes of high quality MC powder.