An in Vitro Study on Antifungal Properties, Total Polyphenolic Content and Antioxidant Activity of Different Parts of Selected Fruit Trees

Abstract

The purpose of this study was to investigate the antifungal properties, total polyphenolic content and antioxidant activity of sapwood, heartwood and bark parts obtained from three different fruit trees; olive (Olea europaea L.), loquat (Eriobotrya japonica Lindl.) and date plum (Diospyros lotus L.) grown in Turkey. Firstly, the hydrodistillation products (essential oil, hydrosol, hot-water extract) were acquired from these parts of selected trees, and methanol and ethanol extracts of the same samples were also prepared for the analysis. The antifungal activities of essential oil, hydrosol, hot-water extract, ethanol and methanol extracts were determined against wood-rot fungus Coniophora puteana. In addition, polyphenol contents and antioxidant activities of ethanol and methanol extracts were investigated. According to the results, generally, the essential oil of the parts of three fruit trees was found to inhibit the fungal growth. All hot water extracts and hydrosols of these trees showed no antifungal activity against C. puteana. It was found that olive tree had higher antifungal activity than loquat and date plum trees. The methanol extract of loquat bark gave the highest total phenolic content, total flavonoid content and condensed tannin content compared to parts of the other trees. Furthermore, the highest total polyphenol content and antioxidant activity among three fruit trees were determined in ethanol and methanol extracts of the bark and heartwood of loquat tree. Based on these findings, it can be concluded that the parts of studied fruit trees have less or more antifungal and antioxidant activity depending on the experimental parameters, and therefore they can be evaluated as alternative natural antifungal and antioxidant sources.