Green Extraction and Characterization of Selected Bioactives and Essential Oil from Citrus Fruit Peel and Assessment of their Antioxidant Potential

Abstract

Citrus fruits are well known for their high nutritional value and multiple health benefits. The medicinal benefits and biological properties of citrus fruit and citrus by products are attributed to the existence of important functional /bioactive components (phenolic components, carotenoids and ascorbic acid) along with essential oil. Pakistan is one of the major citrus producing countries of the world. Processing of citrus fruits into different products or their consumption as such produce agro-waste such as peel, seed, and pulp which are usually wasted. The bioactive components, especially recovered from citrus peel can be potentially used for various food and pharmaceutical applications with the perspective of value-addition. Moreover, recently, there is greater focus on the use of some green solvents for isolation of bioactive components from plant materials, especially for uses in food and nutraceutical industry. The present research work has been planned for extraction of selected functional components from peel of different citrus fruits followed by evaluation of their antioxidant potential. Efforts have been made to devise green extraction protocol to extract/isolate functional components by involving the use of green solvents and ultrasound- assisted extraction technique. The bioactive extracts obtained have been evaluated for antioxidant attributes using different antioxidants assays (TPC, TFC, DPPH etc.). Advanced spectroscopic and chromatographic techniques have been used for characterization of functional components in the extracts and volatile oils isolated. The results of this study indicated that peels of Citrus species are rich source of phenolics, flavonoids and possess antioxidant potential making them suitable enough to be used in nutraceuticals as a source of natural antioxidants.