Rapid separation of carotenes and evaluation of their in vitro antioxidant properties from ripened fruit waste of Areca catechu – A plantation crop of agro-industrial importance

Abstract The waste product generated during arecanut processing is the ripened pericarp. The ripened pericarp tissue of Areca catechu accumulates carotene compounds, nevertheless remained unexplored as a source of tapping colourants. A reverse phase-thin layer chromatography (RP-TLC)-based separation was standardised for the first time for pericarp carotenes in A. catechu . UV–vis spectroscopy formed the basis for identification of major pericarp carotenes, and the method was validated subsequently. Solid phase extraction was also performed for rapid separation of β-carotene, using Sep-Pak ® cartridge. It was found that β-carotene constitutes ∼30% of the total carotenoid content in the pericarp tissues. The total carotenoid content was found to be 11.67 ± 0.62 mg β-carotene equivalent per 100 g fresh mass of pericarp tissue. The antioxidant capacities of the extractives were evaluate by four different commonly used in vitro assays namely, ferrous reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) and DNA nicking assay. Results of all the antioxidant assays point out a significant antioxidant property of the agro-industrial fruit waste of A. catechu .