Biotransformation of polyphenols for improved bioavailability and processing stability.

Research on the functions and effects of polyphenols has gained considerable momentum in recent times. This is attributed to their bioactivities, ranging from antioxidant to anticancer activities. But their potential is seldom fully realized since their solubility and stability is quite low and their bioavailability is hampered due to extensive metabolism in the body. Biotransformation of polyphenols using enzymes, whole cell microbes, or plant cell cultures may provide an effective solution by modifying their structure while maintaining their original bioactivity. Lipase, protease, cellulase, and transferases are commonly used enzymes, with lipase being the most popular for carrying out acylation reactions. Among the whole cell microbes, Aspergillus, Bacillus, and Streptomyces sp. are the most widely used, while Eucalyptus perriniana and Capsicum frutescens are the plant cell cultures used for the production of secondary metabolites. This chapter emphasizes the development of green solvents and identification of different sources/approaches to maximize polyphenol transformation for varied applications.