# The Remarkable Properties of Oil-in-Water Zein Protein Microcapsules

## TL;DR

Researchers created oil-filled protein microcapsules from corn protein that can release active substances like curcumin under specific conditions.

## Contribution

The novel contribution is the development of stable, redissolvable zein microcapsules for controlled release of bioactive compounds.

## Key findings

- Zein microcapsules formed a stable shell around soybean oil, preventing compound diffusion.
- Microcapsules could be redissolved in water while maintaining spherical shape.
- Curcumin release from microcapsules was successfully triggered by temperature and pH changes.

## Abstract

Zein (ZP) is the major storage protein of corn (maize). It is safe, biodegradable, edible, and characterized by unique self-assembly properties. These properties were exploited to prepare ZP microcapsules filled with soybean oil (SO) by ultrasound-assisted emulsification of oil-in-water (o/w) dispersions under optimal experimental conditions. The morphology and stability of o/w ZP/SO microcapsules were investigated by optical spectroscopy (electronic circular dichroism and fluorescence) and dynamic light scattering, as well as bright-field, laser confocal fluorescence, and scanning electron microscopies. The results showed that ZP formed a stable protein shell protecting the inner oily phase from diffusion of the confined compounds. It was also found that ZP/SO microcapsules, stored under suitable conditions, could be redissolved in water, maintaining their spherical morphology. Proof-of-principle studies on the inclusion and release of curcumin, a very active anti-inflammatory and nutraceutical substance, from ZP/SO microcapsules under temperature and pH stimuli are also reported.