Determination of minerals, vitamin content and antioxidant activity of cucumber and watermelon fruits from South-Western part of Nigeria

Abstract

This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Abstract Fruits are indispensable in today's world owing their tremendous health benefits. Cucumber and watermelon are commonly consumed fruits worldwide. In this study, antioxidant potential of crude methanol extract of different concentrations of cucumber and watermelon were screened for antioxidant activity using total phenolic content, ferric reducing power (FRAP), ferric thiocyanate (FTC) tests and free radical scavenging (DPPH) assay. They are good source of calcium, magnesium and copper with appreciable amounts of vitamin C (143.360 ± 101.400 mg/100 g) for cucumber and vitamin A (90.980 ± 22.860 mg/100g; 29.475 ± 0.575 mg/100 g) for both watermelon and cucumber respectively. It was found that polyphenolics compounds were maximum in watermelon (87.04 ± 0.55 mg/g GAE in concentration 100 mg/mL). The extracts showed a potent DPPH free radical scavenging activity; cucumber had maximum percentage inhibition at 20 g/mL concentration (29.2%) compared to watermelon at 40 g/mL concentration (13.5%). These fruits also exhibited fairly good antioxidant activity with in both FRAP (0.517 mg/100 g; 0.317 mg/100 g) and FTC (17.2%; 31%) methods for watermelon and cucumber respectively.