Keynote Speech (Encapsulation of polyphenols and dietary fiber-based colon-targeted delivery)

Abstract

Natural polyphenols, abundant in plants, are vital components of both human and animal diets, boasting a diverse range of biological activities like antioxidant, anti-inflammatory, antibacterial, and antiviral functions. Evidence from preclinical studies and epidemiological data indicates that these compounds may slow down cancer progression, reduce the risk of cardiovascular and neurodegenerative diseases, diabetes, osteoporosis, and potentially offer therapeutic effects for colon-related diseases and gut microbial imbalances. Over recent decades, there has been significant interest in researching and applying polyphenols in functional foods, nutraceuticals, and pharmaceuticals. However, while polyphenols show promise in vitro, their effective concentrations often surpass what is achievable in vivo. Maintaining the bioavailability of these active compounds poses a considerable challenge. Factors such as limited gastric residence time, low gut permeability and solubility, and susceptibility to degradation during food processing, storage, and digestion hinder their efficacy and health benefits. Thus, effectively delivering these compounds requires protective mechanisms to preserve their activity until consumption and target their delivery within the body. Microencapsulation technology offers a solution by encapsulating polyphenols in miniature, sealed capsules. This approach addresses the challenges of instability, unpleasant taste, and poor bioavailability associated with free polyphenols. Encapsulation of polyphenols enhances both in vitro and in vivo bioavailability, prolongs the compounds’ half-life, and facilitates targeted delivery to specific organs, thereby improving their functionality. Based on the keynote speakers two publications (Fang & Bhandari, 2010; Tang, Fang, Ng, 2020), the technologies of encapsulation of polyphenols including spray drying, coacervation, liposome entrapment, inclusion complexation, cocrystallization, nanoencapsulation, freeze drying, yeast encapsulation and emulsion will be discussed. Recent development of colon-targeted polyphenol delivery systems using dietary fibre-based encapsulation technologies will also be elaborated. This keynote speech will expand our knowledge on effectively using encapsulation technologies to improve the stability and bioactivity of polyphenols for human health.