Assessment of quality and food safety of vegetable oils produced on the base of wild berries of Kazakhstan`s forest areas

Abstract

Many species of forest plants in combination with vegetable oils are the sources of new types of functional products with increased biological efficiency. In respect that the high demand for vegetable oils among the population and industry, the growing anthropogenic pressure on various components of the natural environment, the goal of the research was to create oil mixtures based on sunflower oil and wild berries selected in the forest areas of Kazkhstan`s regions, assess their quality and food safety. The base of the oil mixture was sunflower oil obtained from sunflower seeds by the "cold squeeze" method. Wild berries selected from forest areas of northern (Elaeagnusrhamnoides (L.) A. Nelson) and eastern (Rosa majalisHerrm.,Vacciniummyrtillis L.) of Kazakhstan were used as bio-additives. In the obtained oil mixtures, the basic parameters of their qualitative and quantitative composition were studied. It was found that by density (917-918), refractive index (1,473), acid number (1,4 mg KOH/g), iodine number (130-132 g J2/100), saponification number (188 mg/g) of the tested oil mixtures they correspond to unrefined vegetable oil of higher grade. The content of heavy metals (Pb, As, Cd, Cu, Zn, Mg) and radionuclides (90Sr, 137Cs) does not exceed the maximum permissible concentrations and meets the requirements of regulatory documents and standards. In samples of vegetable oils, the amount of oleic acid (52,21%), linoleic acid (28,97%) is determined, which are within the normal range, although they are adjacent to the levels of the upper limits. NMR spectroscopy confirmed that the optimal ratio of ω-6 and ω-3 polyunsaturated fatty acids in the composition of the studied vegetable oils correspond to their name in the ratio of monounsaturated and polyunsaturated fatty acids.