fatty acids profile and trans isomers assessment of currently available margarines in iran(2003)

introduction: cholesterol and fatty acids are two important components of the lipids. various fatty acids have different effects on plasma lipoproteins. consumption of saturated fatty acids tends to increase total plasma and ldl cholesterol levels. while  polyunsaturated fatty acids reduce both ldl and hdl cholesterol, edible oil rich in monounsaturated fatty acid (mufa) however, tend to lower ldl-cholesterol without affecting hdl levels. trans fatty acids which are produced during industrial hydrogenation not only increase the ldl but also reduce the hdl cholesterol and their consumption contribute to increased risk of coronary artery disease. since different margarines have recently been manufactured and introduced as healthier alternatives to butter, this study was aimed to evaluate the fatty acid profile of currently available margarines in iran. materials & methods: different commercial brands (6 brands) of currently available margarine in iran were purchased and subjected to fatty acid analysis in a descriptive study. extraction of fatty acids was performed using the folch method. after the saponification and derivatization of the fatty acids, the samples were submitted to analysis by a hplc method using a gradient of methanol and water as the mobile phase and an ods column as the stationary phase. results:   our results show that the mean of trans fatty acids consisted of 24% and total trans and saturated fats accounted for 51.2 % of total margarine fatty acids, respectively.  in some samples the total trans and saturated fatty acids were more than 60% of the total margarine fatty acids. conclusion: the result of this study showed that there are a lot of cholesterol rising saturated and trans fatty acids in currently available margarines in iran, which their intake is positively related to coronary artery diseases. comparing our results with the available data on fatty acids profile of margarines in the literature our samples contain more amounts of saturated and trans fats. this study proposes that substantial improvement of these products must be done and people should be warned about the adverse health effects of margarine.