identification of chemical compounds, total phenol and flavonoid contents, antioxidant potential of citrus paradisi essential oil, and its effect on fungi cause spoilage strawberry fruit

Background and objectives: citrus paradisi belongs to the rutaceae family, which is found in the north and south of iran. the purpose of this study was to extract grapefruit essential oil (geo) by water distillation and identify its chemical compounds with the help of a gas chromatography device connected to a mass spectrometer (gc-ms). also, the total phenolic content (tpc), total flavonoid content (tfc), antioxidant activity and antifungal effect were investigated. materials and methods: in this study, geo was first extracted by water distillation method and its chemical compounds were identified with the help of a gc-ms. the tpc and the tfc of the essential oil were determined using folin–ciocalteu method and aluminum chloride colorimetry, respectively. antioxidant activity of essential oil with 3 methods of dpph (2,2-diphenyl-1-picrylhydrazyl) free radical inhibition, abts (2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) free radical inhibition and decolorization β-carotene-linoleic acid was determined. four different methods were used to evaluate the antifungal properties of geo on rhizopus stolonifer (atcc 14037), botrytis cinerea (atcc 28387) and aspergillus niger (ptcc 5010). results: the main compound in geo was limonene (77.50%). the essential oil had tpc equal to 92.75 mg of gallic acid per gram and tfc equal to 61.50 mg of quercetin per gram. the antioxidant activity was of geo against dpph radicals (29.90 mg/ml), abts (26.60 mg/ml) and β-carotene oxidation (60.25%). according to the results of disk diffusion agar, botrytis cinerea showed the largest inhibition zone (17.80 mm), while aspergillus niger showed the smallest (13.30 mm). the minimum inhibitory concentration values ​​for botrytis cinerea were equal to 4 mg/ml and for aspergillus niger equal to 16 mg/ml. conclusions: it is suggested that more research on other pathogenic fungi and also the effect of essential oil on horticultural products should be investigated.