ABSTRACT
Fermentation is one of the most significant ancient practices in history to create stable and different foods with desired organoleptic properties. It is a way of natural decomposition of organic materials into simpler compounds by the action of inherent microorganisms of plant or animal origin. Some of fermented foods and drinks are still a part of our everyday diets. Through ages, people have also realised the nutritional and health benefits of fermented foods and drinks. Recent studies related to phenolics have shown that food processing methods might be related to the increased bioavailability of polyphenols. In this respect, among many of the food processes, fermentation is unique as it enables intrinsic constituents, secondary metabolites, detoxification of toxic components/residues which help in an increase of functionality of the food product. Fermentation studies are conducted in numerous different matrices which have clearly indicated that fermentation enhances the antioxidant capacity of dietary polyphenols. However, use of different substrates, different starter strains and different methods to assess antioxidant activity may be considered as factors to have sometimes contradicting results about the effects of fermentation. Therefore, this chapter aims to give an overall understanding on the effects of fermentation on polyphenols, emphasising the main product types and main findings in literature.
