EVALUATION OF SUNFLOWER, FLAXSEED AND OLIVE OILS IN TERMS OF CHEMICAL COMPOSITION AND THEIR PHYSICAL AND CHEMICAL PROPERTIES

: Fats are an essential component of human diets and their types greatly affects public health, and some of them may cause many diseases, such as cardiovascular diseases and fatty liver. Since sunflower, flaxseed and olive oils are among the oils commonly used in nutrition in Egypt, the study was conducted to compare the components of these oils and their nutritional value to evaluate them. The fatty acid components of these oils were estimated, and the sterols present in each oil were estimated using the Gas Chromatograph (GC). The physical and chemical properties of each oil were also estimated (specific gravity, refractive index, color, oxidative stability index, saponification value, iodine value, acid value, ester value, peroxide value and % unsaponifiable matter). Linoleic acid was the largest component in sunflower oil (53.33%); oleic acid was the largest one in olive oil (66.65%), while alpha-linolenic acid was the largest component in flaxseed oil (55.34%). For sterols, β-sitosterol (44.86%), stigmasterol (20.33%), campesterol (11.68%), isofucosterol (9.54%) components were the largest in sunflower oil. Squalene (64.14%) and β-sitosterol (16.78%) were the largest sterols in olive oil. While β-sitosterol (28.24%), campesterol (16.37%) and cycloartenyl acetate (12.42%) were the largest sterols in flaxseed oil. The results clearly show a high content of sunflower oil of omega-6 fatty acids, while flaxseed oil was distinguished by its high content of omega-3 fatty acids, and olive oil was the highest in its content of omega-9 fatty acids. Therefore, these oils are well suited for use in nutrition, and more studies are needed to reach the best ratios of the mixture of these oils in biological experiments.