title: Influence of different solvents in extraction of phenolic compounds from vegetable residues and their evaluation as natural sources of antioxidants.
abstract: Dried residues from four different vegetables, viz. pea pod (pp), cauliflower waste (CW), potato peel (PP) and tomato peel (TP) were extracted using four solvents i.e., hexane, chloroform, ethyl acetate and methanol. Among the four solvents, methanolic extracts showed the highest total phenolic content (TPC) for all the four vegetable residues. Methanolic extracts were evaluated for antioxidant activities using diphenylpicryl-hydrazyl (DPPH) and reducing power assay. Tomato peel extract showed highest phenolic content of 21.0 mg GAE/g-dw and 80.8 % DPPH free radical scavenging ability, whereas potato peel extract had a low phenolic content, and it also showed the least antioxidant activity among the residues examined in this study. Total phenolic content and DPPH free radical scavenging activity in pea pods and cauliflower waste were 13.6 mg GAE/g-dw and 72 % and 9.2 mg GAE/g-dw and 70.7 %, respectively. The coefficient of determination (r(2)) for correlation between TPC and reducing power, DPPH and TPC, DPPH and reducing power for all extracts was 0.85, 0.91and 0.87, respectively, suggesting an important role of phenolics in imparting antioxidant ability. Extracts from vegetables residues therefore represent a significant source of phenolic antioxidants for use as nutraceuticals or biopreservatives.
authors.affiliation: Central Institute of Post-Harvest Engineering and Technology, Ludhiana, 141 004 India.
authors.forename: Neha
authors.initials: N
authors.lastname: Babbar
authors.affiliation: Central Institute of Post-Harvest Engineering and Technology, Ludhiana, 141 004 India.
authors.forename: Harinder Singh
authors.initials: HS
authors.lastname: Oberoi
authors.affiliation: Central Institute of Post-Harvest Engineering and Technology, Ludhiana, 141 004 India.
authors.forename: Simranjeet Kaur
authors.initials: SK
authors.lastname: Sandhu
authors.affiliation: Central Institute of Agricultural Engineering, Bhopal, 4620 038 India.
authors.forename: Vinod Kumar
authors.initials: VK
authors.lastname: Bhargav
keywords: Antioxidant activity; Correlation; DPPH; Reducing power; Total phenolic content vegetable residues