Bioaccessibility and Bioavailability of Phenolic Compounds in Seaweed

ABSTRACT

Seaweeds are rich in phenolic compounds such as phlorotannins and have antioxidant, antibacterial, and anti-inflammatory activities. As exogenous bioactive compounds, seaweed polyphenols exist in the form of aglycone, esters, glycosides, and polymers. Most of them are not directly absorbed in the human digestive tract but undergo extensive modifications by digestive enzymes or bacteria before absorption or excretion. Up-to-date in vitro and in vivo seaweed polyphenol bioaccessibility studies have been reviewed, outlining seaweed polyphenols, especially phlorotannins, have low oral bioaccessibility, bioavailability, and high bioactivity paradox. Moreover, special attention is also given to other factors such as food matrix, food processing methods, and host factors on the absorption of seaweed polyphenols. In digestion tract, proteins can form both covalent and non-covalent bonds with polyphenols and thus hinder the absorption of polyphenols. However, lipids and polysaccharides in food can enhance the bioaccessibility of polyphenols to some extent. It is worth noticing that food processing technologies and host gut flora composition can also alter the absorption and bioactivity of specific seaweed phenolics.

GRAPHICAL ABSTRACT

KEYWORDS:

• Seaweed
• phenolic compound
• gastrointestinal digestion
• bioaccessibility
• bioavailability
• metabolism

Acknowledgments

We would like to thank the Honours/Master/PhD and Postdoc researchers of the Dr Hafiz Suleria group from the School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, the University of Melbourne for their incredible support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Dr Hafiz Suleria is the recipient of an “Australian Research Council -Discovery Early Career Award” [ARC-DECRA DE220100055] funded by the Australian Government. This research was funded by the University of Melbourne under the “McKenzie Fellowship Scheme” [Grant No. UoM-18/21] and “Collaborative Research Development Grant” [Grant No. UoM-21/23] funded by the Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Australia. This research project (ID 302611; Characterisation of seaweed phenolics and their antioxidant potential) is also supported by InnoVactiv Inc., Rimouski, QC, Canada and the University of Melbourne, Australia.