Abstract
Vegetable oils are a valuable multivitamin raw material for the food and pharmaceutical industry due to the content of effective biologically active organic components and mineral substances. To assess the quality and food safety of unrefined vegetable oils obtained from sunflower seeds and flax of Kazakhstan agro-formations by the method of «cold pressing,» we studied the basic indicators of their qualitative and quantitative composition. It was found that the organoleptic characteristics (transparency, color, smell and taste) of the tested vegetable oils correspond to unrefined sunflower oil of the highest grade, unrefined linseed oil of the first grade. Studies of the physicochemical parameters of sunflower and linseed oils: colored number (14,40 mg of iodine), acid number (1,4-1,5 mg KOH/g), weight fraction of phosphoruscontaining substances (0,18% and 0,5%), humidity (0,13%; 0,17%), peroxide number (6,7 and 9,0 mmol of active O2/g), iodine number (132 and 176 gJ2/100) and saponification number (188 and 187 mg/g) also correspond the requirements of regulatory documents and standards. In sunflower oil samples, the amount of oleic acid is 52,21%, linoleic acid 28,97% is determined, which are within the normal range, although they are adjacent to the levels of higher limits. Analysis of linseed oil fatty acids showed that samples contain linolenic acid 50,1%, All other fatty acids are noted within the permissible limits, and oleic acid 14,13%, linoleic acid 17,9% are close to the upper limits of permissible limits. NMR spectroscopy confirmed that the optimal ratio of ω-6 andω-3 of polyunsaturated fatty acids in the composition of the studied vegetable oils correspond to their name in the ratio of monounsaturated and polyunsaturated fatty acids.