# Improved rehydration characteristic of micellar casein powder by electrostatic spray drying

## TL;DR

This study shows that electrostatic spray drying improves the rehydration of micellar casein powder compared to other drying methods.

## Contribution

Electrostatic spray drying is shown to enhance micellar casein powder hydration and stability.

## Key findings

- ESD powder dissolved 96% within 16 hours with minimal sediment.
- ESD powder had higher solubility and smaller particle size than freeze and spray drying.
- ESD improved hydration efficiency and reduced hydrophobic exposure.

## Abstract

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.

•·Electrostatic spray drying (ESD) improved the solubility of micellar casein powder.•·ESD-produced micellar casein powder had higher κ-casein and faster water erosion.•·ESD-produced micellar casein powder exhibited smallest particle size.

·Electrostatic spray drying (ESD) improved the solubility of micellar casein powder.

·ESD-produced micellar casein powder had higher κ-casein and faster water erosion.

·ESD-produced micellar casein powder exhibited smallest particle size.