Health Benefits of Microencapsulated Dietary Polyphenols: A Review

Isolated dietary polyphenols are subjected to degradation under unfavorable conditions leading to the loss of their bioactivity. Microencapsulation has attained research interest for enhancing the stability, improved bioavailability of polyphenols, and targeted delivery. This review examines the effects of microencapsulation on health promotion compared to non-encapsulated polyphenol extracts as evidenced through in vitro, experimental animal, and human intervention studies. Most of the research confirms that microencapsulation enhances the extent of bioaccessibility and bioavailability of polyphenols. Also, encapsulated polyphenols have exhibited greater antidiabetic, anti-inflammatory, anticancer, and antimicrobial effects than non-encapsulated polyphenols. Interestingly microparticles are not found to create any cytotoxicity. Nevertheless, a few studies demonstrate either low or similar health effects of encapsulated form to their unprocessed form. Future research should mainly focus on human trials to better understand the contribution of microencapsulation to human health. Importantly, investigations should include non-encapsulated polyphenols as well to compare relative efficacy improvement by microencapsulation.