Flavonoids capture and neutralize the oxidative agents, and quench free radicals. The peel which represents almost one half of the fruit mass has been found to be the main sources of total phenols and flavonoids in the citrus fruit. In present study, flavonoid content and in vitro antioxidant activities of ethanol extracts from some selected citrus fruit peels grown in Ethiopia were determined. Colorimetric aluminum chloride was used for flavonoid content determination. In vitro antioxidant properties of the citrus fruit peels were determined by measuring DPPH and Nitric Oxide radical scavenging activity, and reducing power. The study result showed that lemon peel contained significantly the highest flavonoid content (8.88 ± 0.621 mg of quercetin equivalent/g of extract) at 100 µg/ml concentration. When compared to vitamin C used as standard, lemon peel extract showed significantly higher DPPH radical scavenging of 75.60 ± 2.4 %. Lime peel extract showed highest (0.38 ± 0.01) reducing power activity at 1000 µg/mL concentrations. Strong linear correlations was observed between flavonoid contents of selected citrus peel extract and DPPH free radical scavenging activity (r = 0.975, p = 0.025). Overall, in vitro antioxidant potential of citrus fruit peels extract grown in Ethiopia was confirmed and correlation between in vitro antioxidant activity and flavonoid content of citrus peel extract showed different trends. Further analysis is required to purify specific structure of flavonoid components of citrus fruit peel from Ethiopian cultivar using advanced purification techniques.
|Supporting Institution||The office Vice President for Research Affairs, Haramaya University|
|Thanks||We thank Haramaya University, Vice president for Research Affairs to fund the mega project coded HURG-2016-06-01-05 from which this manuscript extracted. We also gratitude the Dire Dawa District farmer for their willing to provide us with the fruit.|
|Publication Date||March 20, 2020|
|Published in Issue||Year 2020, Volume 7, Issue 1|