Antioxidant effect of <i>Citrullus vulgaris</i> (watermelon) extract against lipid oxidation in fish during cooking

Abstract

The Antioxidant effect of Citrullus Vulgaris (Watermelon) extract was evaluated against lipid oxidation in freshly caught fishes during cooking. GC-MS analysis of Hexane and total phenolic extract of Citrullus Vulgaris flesh reveals that the extracts contain 55 compounds which includes 5- hydroxymethyl furfural, 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-, Hexadecanoic acid, ethyl ester and Palmitic acid ester that are reported as antioxidants. Muscle flesh of fifteen (15) samples of freshly caught fish comprising Group I (Tilapia zilli; n=5), Group II (Clarias hollandis; n=5) and Group III (Clarias gariepinus; n=5) were prepared and Sub Grouped each as Control, Treatment 1, Treatment 2, Treatment 3 and Treatment 4 which receives 0, 50, 150, 250 and 450mg of Citrullus Vulgaris extract per 100g fresh fish muscle weight respectively. Treatment 4 gave the highest protection against lipid oxidation in all groups, however the concentration of MDA in Treatment 3 of Group I and III were not significantly (p>0.05) higher as compared to Treatment 4 of same Groups. The results clearly suggested that the extract effectively prevented lipid oxidation in fish and that the rate of prevention is a factor of fish species and extract concentration.Keywords: Fish, citrullus vulgaris, lipid oxidation, Antioxidants, Malondialdehyde (MDA)