Extraction characterization and Functional properties Of finger millet polyphenols and Their applications in Food systems

Abstract

Polyphenols are a large and diverse group of phytochemicals mostly found as secondary metabolites in plants. They contain one or more aromatic rings with one or more hydroxyl groups attached. Dietary polyphenols are largely present in fruits, vegetables, cereals, legume seeds, millets, tree barks, nuts, oilseeds, green and black tea, red wine and certain spices. They are increasingly recognized as functional ingredients with multiple health benefits. The antioxidant activity of polyphenols has preventive and therapeutic value with respect to degenerative diseases, particularly neurodegenerative diseases, cardiovascular diseases and cancers. Finger millet (Eleusine coracana), a minor millet, grown in Asia and Africa is an ideal source of polyphenols among the cereals. It is considered as potent millet for its antioxidant activity owing to its bioactive components. The uniqueness of finger millet lies in the presence of the five layered seed oat/testa, which could be one of the possible reasons for the higher polyphenol content compared to other millets. The seed coat forms a byproduct/adjunct of the millet processing industries during the process of malting; has high potential to be utilized in food based applications and as utraceuticals to promote health, prevent and manage diseases. However there are no reports on the use of these by products in food based applications. The effective utilization of the phytochemicals or bioactive compounds depends on potential of the extraction process carried out. The conventional methods commonly followed for polyphenol extraction from finger millet have low efficiency, due to long duration and high temperature requirements used during the course of extraction and the toxic remains in the final product due to the acidic solvents used, thereby being a cause of concern as environmental hazards impacting human health newline