Investigation of Oxidation Rate Relationship Between Fatty Acid Contents of St. John’s Wort (Hypericum perforatum) Oil and Nettle (Urtica dioica) Seed Oil

Abstract

Vegetable extract oils are now widely used in health, cosmetics and food fields. Theoxidation rates of these industrial oils are closely related to their chemical composition. Inthis study, fatty acid contents of St. John’s Wort (Hypericum perforatum) oil and Nettleseed (Urtica dioica) oil were investigated by gas chromatography (GS-MS) and theeffects on lipid peroxidation time were tried to be related. The peroxidation of oilemulsions was carried out at in a ventilated incubation environment 37°C and pH 7.Pseudo first order constants of primer oxidation products (hydroperoxides) werecalculated by Fe (III) SCN method and they found for St. John’s Wort oil and Nettle seedoil, (2.05±0.23)×10-1 and (6.64±0.54)×10-1 hour-1,respectively. This study was conductedby showed that the oxidation rates of St. John’s Wort and Nettle seed oils are closelyrelated to the chemical composition as well as the saturation ratings of fatty acids.