Tocopherol content in cold-pressed oil from different sunflower hybrids grown in Serbia

Abstract

Vegetable oils rich in antioxidant are of great interest in the food industry as they decelerate oxidative degeneration of lipids and therefore promote the quality as well as the nutritional value of food. Sunflower (Helianthus annuus L.) is one of the most abundant annual crops in the world that is grown for edible oil which is a good source of bioactive compounds. Tocopherols belong to the most important bioactive compounds in oil which have many health benefits for human. These compounds preserve oil from peroxidation by scavenging lipid peroxyl radicals. In humans, tocopherols play an important role as vitamin E, contributing to maintaining the immune system and delaying the pathogenesis of a variety of degenerative diseases. Over the last few years, increased interest for natural antioxidant in cold‐pressed plant oils has been observed since they have better nutritive properties in comparison with refined ones. In this work, three cold-pressed sunflower oils obtained from sunflower hybrids cultivated in Serbia (2017 harvest) were studied for their contents. Quantification of tocopherols was carried out using high performance liquid chromatography on a column Nucleosil 100-5 NH2 with fluorescence detection (λex=280 nm, λem=340 nm). The mobile phase was n-hexane/ethyl acetate (70/30%v/v) with a flow rate of 1 ml/min. The relative retention value and maximum values of absorption at the given relative retention time were used to identify and confirm the presence of tocopherolsin injection volume of 20 μl solution samples obtained by diluting of oil (300 µL) in n-hexane (2 ml). This research verified the dominant presence of α-tocopherol in cold-pressed sunflower oils. The content of α-tocopherol ranged between 497.40 mg/kg oil in NS Oliva hybrid and 691.46 mg/kg oil in NS Romeohybrid. The results have shown that there were differences in content of tocopherols among tested hybrids, indicating the great genetic potential for improvement.