Zein/chitosan composite nanospheres for controlled release of fragrances

Abstract

The controlled release of fragrances is critical for cosmetics industry, but most traditional fragrance carriers have some limitations. In this study, ethanol soluble protein zein was selected as the matrix to encapsulate ethanol soluble cinnamaldehyde (CA) with the addition of another natural polymer chitosan (CS), forming composite nanospheres. The zein/CS composite nanospheres showed three different structures depending on the zein/CS mass ratio. The hydrophobic interaction between CA and zein, and the formation of Schiff base between CA and CS significantly reduced its volatilization rate to the air. In addition, it was found that the loading capacity, encapsulation efficiency, controlled release property, and antibacterial activity of the CA-loaded zein/CS composite nanospheres were closely related to their structure. The nanospheres with core (zein)/shell (CS) or homogenous structure displayed long CA release time (more than 1 day) and sustained antibacterial activity against Staphylococcus aureus. Therefore, the CA-loaded zein/CS composite nanospheres are promising carriers for developing antibacterial perfumes and coatings.