Fermentation plays a crucial role in altering the bioactivity and composition of polyphenols in polyphenol-rich foods. Polyphenols, present in plants in forms like tannins and anthocyanins, are known for their functional activities but often exhibit low bioavailability. Polyphenol-rich fermented foods (PFFs) have gained attention for their enhanced bioavailability and bioactivity due to the breakdown of polyphenols into smaller compounds with higher bioactivity during fermentation. Enzymes like tannases, esterases, and glycosidases secreted by microorganisms facilitate this biotransformation. Additionally, polyphenols promote the growth of beneficial bacteria while inhibiting pathogenic bacteria during fermentation, highlighting the dynamic interaction between polyphenols and microorganisms in PFFs.
The traditional role of fermentation in food preservation and flavor enhancement has expanded to include the promotion of functional activities in fermented foods. Fermented foods, derived from plant and animal sources, exhibit diverse functional activities like hypoglycemic, antioxidant, and antimicrobial effects, attributed to the bioactive components generated during fermentation. Plant fermented foods, rich in polyphenols like flavonoids and phenolic acids, show promising health benefits due to the transformation of large-molecule polyphenols into smaller, more bioactive forms during fermentation. This shift in focus from flavor to functionality has led to increased research interest in polyphenols in fermented foods.
Polyphenols, a group of plant secondary metabolites with diverse biological activities, are categorized into flavonoids and non-flavonoids. The vast range of phenolic substances identified showcases the complexity of polyphenols present in foods. However, only a small percentage of dietary polyphenols are absorbed by the body, with the remainder interacting with gut microbiota to confer health benefits. The biotransformation of polyphenols during fermentation is crucial for enhancing their bioavailability and bioactivity. By hydrolyzing glycosidic bonds and breaking down complex structures, microorganisms contribute to the release of free phenols, thereby increasing the functional potential of fermented foods.
Microorganisms play a pivotal role in metabolizing polyphenols during PFF fermentation. Enzymes like tannases, esterases, and glycosidases secreted by microorganisms facilitate the breakdown of complex polyphenols into smaller, bioactive compounds. The transformation of large-molecule polyphenols into smaller forms during fermentation results in significant changes in the composition and functional activities of PFFs. For instance, the conversion of proanthocyanidins into oligomeric forms enhances the antioxidant properties of fermented foods. This intricate interplay between microorganisms and polyphenols underscores the importance of understanding the biotransformation pathways in PFFs.
Biotransformation pathways of tannins and proanthocyanidins during fermentation illustrate the intricate processes involved in converting complex polyphenols into bioactive compounds. Tannases, esterases, and glycosidases play key roles in degrading tannins and proanthocyanidins into simpler forms, thereby enhancing the bioavailability and functional activities of fermented foods. The systematic breakdown of polyphenols by microorganisms highlights the potential of PFFs as functional foods with improved health benefits. Further exploration of the interactions between polyphenols and microorganisms during fermentation holds promise for enhancing the nutritional value and bioactivity of polyphenol-rich foods.
Tags: fungi, secretion, yeast, probiotics, metabolomics, validation
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