Evaluation of nutritional value and antioxidant activity of tomato peel extracts

The objective of this work was to study the nutritional composition and the antioxidant activity of some tomato peel extracts. Preliminary chemical composition, minerals content, amino acids, fatty acids and phenolic compounds of the peels were determined. The extracts which had been obtained by using different solvents; petroleum ether, chloroform, ethyl acetate and methanol were assayed for their antioxidant activity. Antioxidant activities of the extracts were evaluated by the determination of peroxide, malondialdehyde (MDA), P-anisidine and total carbonyl values during four weeks storage of cottonseed oil at 60 °C. Also, the 1,1-diphenyl-2-picrylhydrazine (DPPH) radical scavenging was carried out. The results revealed that most of the extracts showed significant increases in DPPH scavenging activity as compared to butylated hydroxy toluene (BHT), an artificial antioxidant. On the other hand, significant decreases in peroxide, P-anisidine, malondialdehyde and carbonyl values were observed in the oil samples treated with the extracts in comparing with the untreated sample (control). Due to tomato peel content of many nutrients and its antioxidant activities, tomato peel or its extracts can be used as a food supplement.