Research Mentor and Department
Professor Youngsoo Lee, Department of Food Science & Nutrition at University of Illinois in Urbana-Champaign
Resveratrol is a naturally occurring polyphenolic compound showing health benefits, including anti-carcinogenic, anti-microbial, anti-HIV/AIDS, neuro-protective, and cardio-protective activities. It has been proposed as a promising dietary supplement or functional ingredient in foods to lower the prevalence of many chronic diseases. However, due to the molecule’s chemical instability, low bioavailability, and poor water solubility, its application was vastly limited. Therefore, extensive research has been conducted regarding microencapsulation of resveratrol. In this study, resveratrol was double encapsulated with zein, a prolamine protein found in maize, and chitosan, a hydrophilic, linear polysaccharide derived from chitin via a deacetylation reaction. Due to their biocompatible, biodegradable and nontoxic nature, both zein and chitosan are regarded as GRAS (Generally Recognized As Safe) materials for food applications. Many previous studies have already encapsulated resveratrol with zein and studied various properties of the nanoparticle. However, those approaches still suffer several issues such as resveratrol instability and low encapsulation efficacy. The aim of this study was to analyze the effects of an extra layer of chitosan on resveratrol-loaded zein nanoparticles. Resveratrol-loaded zein and zein/chitosan nanoparticles were prepared using an antisolvent procedure by dispersing zein solution in deionized water and in chitosan solution, respectively, under high-speed homogenization. The morphologies of the nanoparticles were observed under a scanning electron microscope (SEM). Particle size, zeta-potential, crystalline structure, and encapsulation efficiency were analyzed and compared. The results suggest that an extra layer of chitosan on resveratrol-loaded zein nanoparticles significantly decreased the particle size and increased the encapsulation efficiency of resveratrol. High encapsulation efficiency suggests that an extra chitosan layer successfully improved the encapsulation of resveratrol and was able to accommodate for the compound’s key issues. This study further highlights chitosan as a very promising coating material for microencapsulation of not only resveratrol but also potentially for various phenolic bioactive compounds.