A Novel Approach for Extraction of Polyphenols

Abstract

Polyphenols are class of compounds which are found in fruits, vegetables, walnuts, olives, tea leaves and many more. Polyphenols are antioxidant phyto-chemicals that prevent or neutralize the damaging effects of free radicals. They are secondary metabolites of plants and are generally involved in defence against ultra-violet radiation or aggression against pathogens. Polyphenols are various alcoholic compounds containing two or more benzene rings that each has at least one hydroxyl group attached. There are more than 100 naturally available products which contain polyphenols, the major dietary supplements are strawberry, grapes, pomegranate, cloves, spinach, black olive and tea which are available in the country and can be easily consumed. Polyphenols have wide range of applications viz., anti-ageing cosmetics, anti- cancer drugs, drugs to cure chronic disease, anti-oxidant rich beverages, helps in reducing cardio-vascular diseases, also constraints the levels of LDL. Here this review concentrates on a novel approach for extraction of polyphenols from fruit and vegetable waste thereby reducing the waste generation and hazards of waste disposal.  Polyphenols can be extracted by different methods like liquid-liquid extraction, solid-liquid extraction, solid phase extraction, soxhlet extraction, super critical, sub-critical extraction, microwave assisted extraction. These extracts can be quantified by HPLC, GC, TLC and spectrophotometric method. This review concentrates mainly on extraction methods and their applications, the feasibility of the process and the yield obtained.