Effect of different extraction solvents on the antioxidant content and capacity of nine seasonal fruits

Summary: Background: Nine seasonal fruits were analyzed for antioxidants capacity and content. Scientific information about seasonal fruits’ antioxidant properties (capacity and content) depending on the extraction solvent effect is not widely studied. Therefore, the assessment of such properties remains an interesting and useful chore, especially for exploring new sources for natural antioxidants, functional foods, and nutraceuticals. Quantifying the antioxidant content and capacity allows the screening of fruits that are probably involved in the prevention and/or treatment of oxidative stress-associated diseases. Aims and methods: The aim of this study is to compare the antioxidants capacity and content of nine seasonal fruits (banana, figs, white &amp; black grapes, guava, Indian fig, jujube, pomegranate, and strawberry) by using three extraction solvents (ethanol, methanol, and water). Two methods were applied for antioxidant content: Folin-Ciocaltaeu method and total flavonoids method. In addition, two methods were applied for antioxidant capacity: 2,2-diphenyl-picrylhydrazyl (DPPH) as well as the cupric antioxidant reducing capacity (CUPRAC) assays. Results: There were significant (P < 0.05) differences between the fruits in terms of antioxidant content and capacity. Regardless of the extraction solvent, the fruit content of total polyphenols (M catechin/100 g) was as follows: jujube > guava > pomegranate > strawberry > white grapes > black grapes > banana > figs > Indian figs. The total flavonoid content (mM rutin/100 g) of the fruits was: jujube > banana > strawberry > figs > black grapes > white grapes > pomegranate > Indian figs > guava. On the other hand, the antioxidant capacity (M trolox/100 g) of the fruits was: guava > white grapes > Jujube > strawberry > pomegranate > black grapes > banana > figs > Indian figs. The antioxidant capacity (vitamin C mg/ml extract) of the fruits was: jujube > guava > black grapes > pomegranate > figs > strawberry > white grapes > Indian figs > banana. Conclusion: Different extracts of fruits showed significantly (P < 0.05) different antioxidant contents and capacities. Water solvent was the best extraction for antioxidant contents among most of the nine seasonal fruits. Significant correlations between antioxidant content and antioxidant capacity of the studied fruits were found.