Determination of Flavonoid Contents and Evaluation of in vitro Antioxidant Activities of the Extract of Selected Citrus Fruit Peel

Abstract

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.

The Study of Citrus Peels (Citrus amblycarpa) Mass Ratio Substitution on Physicochemical of Rich-Antioxidant of Liang Tea

“…According to the same report, there was no correlation between both total phenolic and flavonoid content against radical scavenging activity in linear regression analysis. On the contrary, several reports showed a strong correlation on phenolic and flavonoid contents of citrus fruit peel extracts against DPPH assay 22,23 . In general, the fruit's peel contains a higher concentration of antioxidant substances than the fruit's flesh 24 .…”

“…A qualitative phytochemical screening test showed significant indication of certain metabolites' presence 26 . Many scientific articles stated that phytochemical content and composition varies due to different factors and one of the factors indicated is environmental difference and variety of the plant 22 . The presence of phytochemical such as alkaloid, flavonoid, phenol, tannin and terpenoid in richantioxidant liang tea.…”

Bioactive Phytochemical Contents on Fruit Peel of Several Citrus Species

“…C. aurantium, C. limetta and C. limon. Erba et al [37] reported the peel of orange, mandarin, lime and lemon has the highest DPPH scavenging activity but different result of DPPH radical scavenging activity was also reported by Singh & Immanuel [38].…”

Validating the protective role of orange and tangerine peel extracts foramending food safety against microorganisms’ contamination using molecular docking

“…The above findings agreed with [ 44 ]. According to the correlation analysis performed by [ 46 ], the essential factor in determining the antioxidant activity potency of phenolic and flavonoids is their molecular structure rather than their content. Therefore, the total contents of phenolic and flavonoids cannot be a critical factor in predicting antioxidant efficiency.…”