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In human nutrition, fats are physiologically important food constituents, which are most liable to oxidative degradation. The oils included in the study were refined and virgin oils of sesame, groundnut, coconut, sunflower and palm oils. The aim of the study was to determine the fatty acid composition and physico chemical parameters of the selected oils. The result showed that the refined oils had highest smoke point ranging from 145 to 2290C compared to virgin oil (131 to 1950C). Virgin oil had maximum iodine value attributes to the higher number of double bonds present in the oil. Virgin sesame oil had the lowest peroxide value 4.5 mEq O2 /kg and the virgin coconut oil had the highest peroxide value 8.0 mEq O2 /kg. This indicated that the traditionally processed virgin oil had peroxide value within the prescribed Codex Standard (10 meq O2/kg). Refined oils had higher content of saturated and monounsaturated fatty acids and lower polyunsaturated fatty acid contents. The fatty acid composition of the virgin oils was better than that of the refined oils. Refined palm oil and sunflower oil are more suitable for deep fat frying than refined sesame oil. Consumption of refined palm oil was found to be positively correlated with the increased level of low density lipoprotein (bad cholesterol) and incidence of Coronary Heart Diseases. Hence, the consumption of virgin sesame oil with high monounsaturated fatty acid has been recommended for improving the lipid profile concentrations followed by virgin groundnut oil.
Keywords: Physico-chemical, refined, virgin, fatty acid, colour value, saponification value Practical application: Knowledge of physical and chemical properties of the virgin and refined oils is essential to select the good oil for healthy lifestyle. Therefore, the information of this work is important for selection of healthy cooking oil.