Total phenolic, flavonoid contents, and antioxidant activity of strawberries and local medicinal plants

Abstract

In this study, we assess and compare the total phenolic content (TPC), total flavonoid content (TFC), tannin content (TC), free radical scavenging activity, and ferric reducing antioxidant power in seven local plants. Two strawberry cultivars (Fragaria x ananassa Duch.) with five native medicinal plants, namely, Pandanus amaryllifolius, Cymbopogon citratus, Centella asiatica, Tiliacora triandra, and Melissa officinalis, are investigated. All the plant extracts were found to contain phytochemical content with antioxidant activity. The leaves of the strawberry “American jumbo” exhibit the highest levels of TPC and TC, while C. asiatica shows the highest levels of TFC (p < 0.05). No significant difference was observed between the free radical scavenging activities of both strawberry cultivars. However, these cultivars exhibited a significant difference (p < 0.05) from others based on the 2,2-diphenyl-1-picryl-hydrazyl-hydrate assay. Therefore, this study clearly reveals that water-soluble extracts of strawberry “Pharachatan 80” leaves is the most promising source of potential natural antioxidants among these plant extracts.