Antioxidant Activity, Antibacterial Screening, Proximate Composition and GC-Mass Spectrometry Analysis of Cantaloupe Seeds

Abstract

Cantaloupe refers to the Cucumis melo species in the Cucurbitaceae family. Seeds are solid by-product generated in large quantity. Regulation of agricultural by-products as a source of bioactive compounds could minimize environmental hazard. For that reason, cantaloupe seeds were evaluated for its antioxidant and antibacterial activities. The current study included the proximate analysis of the seeds that had protein content 20.8%, crude fiber 33.1%, moisture 8% and fat 24.6%. Characterization of bioactive constituents by GC-MS analysis revealed the existence of methionine (60.17%), 4-aminoheptanedioic acid (4.75%), 9-cis-retinoic acid (34.12%) and stearic acid allyl ester (0.96%). Data revealed that total phenolic and flavonoid contents of cantaloupe seeds had range of 50.5 mg GAE/100 g dry weight and 6.43 mg QE/100 g dry weight, respectively. Total antioxidant activity valued 272.6 mg AAE/100 g dry weight. Ferric reducing antioxidant power increased relative to increase the extract concentration which indicated high reducing ability of cantaloupe seeds. Ethanolic extract of cantaloupe seeds had mild inhibition activity against E. coli and Salmonella sp., while Staphylococcus aureus was resistant to the ethanolic extract. Aqueous extract did not show any antagonistic effect against the three pathogenic bacterial strains. Inclusion of phytochemical bioactive compounds and methionine as sulphur-containing amino acid in cantaloupe seeds may contribute to the apparent antibacterial activity against Gram-negative bacteria. Results ensured that cantaloupe seeds possessed nutritional, antibacterial and antioxidant properties.