Lipid composition and physicochemical parameters of unrefined sunflower oil

¹ Analytical and Physical Chemistry Department, University of Food Technologies, Plovdiv, Bulgaria
² Department of Chemical Technology, University of Plovdiv, Plovdiv, Bulgaria
³ Department of Technology of Tobacco, Sugar, Vegetable and Essential, University of Food Technologies, Plovdiv, Bulgaria

^* Corresponding author: ivanz.iliev@abv.bg

Abstract

Unrefined sunflower oil is obtained by pressing of the sunflower seeds and subsequent fine filtration. It contains more biologically active substances compared to the refined one, it is more stable to oxidation processes, for that reason it is widely used in the composition of the various food products. The main acids in the oil are oleic (56.5%), linoleic (31.7%), palmitic (6.4%), and stearic acid (3.2%). Total sterol content is 0.7%, with ß-sitosterol as a main component (84.0%). The quantity of tocopherol is 188 mg/kg and it consists of one compound α-tocopherol (100%). Different physicochemical parameters were obtained at temperature ranges (from 20 to 80°C). The values of these parameters decrease with an increase in temperature, density (from 0.938 to 0.901 g/ml), surface tension (from 44.124 to 31.787 mN/m), dynamic viscosity (from 29.195 to 14.913 mPa.s), and kinematic viscosity (from 31.125 to 16.552 mm²/s). All these changes are in confirmation of the data from the literature and are relevant in our next studies.