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.
