Enhancing vitamin A stability using saponin–chitosan polyelectrolytes coating: Optimization, characterization, and controlled release

Abstract

Microencapsulation has the potential to address the stability issues associated with vitamin A. This study examined the effectiveness of emulsifying a saponin–chitosan polyelectrolyte complex to encapsulate vitamin A. Utilizing response surface methodology (RSM), the effects of the chitosan, saponin, and vitamin A contents on various response variables were measured to optimize the formulation. The optimized emulsion was characterized through fluorescence microscopy, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), storage stability, and release profile. Fluorescence microscopy showed that vitamin A was evenly distributed throughout the optimized emulsion. The polyelectrolyte complex and vitamin A were shown to interact hydrophobically and electrostatically by FTIR analysis. The DSC results verified the effective encapsulation and showed that vitamin A heat stability had been enhanced. Study on storage stability demonstrated that during a 2‐month storage period, the encapsulated vitamin A remained stable. Moreover, vitamin A was significantly released from the encapsulated form at pH 1.2, based on release assays. In conclusion, saponin–chitosan polyelectrolyte coating proved to be a potentially useful new material for the stability and applications of vitamin A in a range of formulations.