Evaluation of the influence of different heat-treatment methods on fatty acids content particulary trans isomers in french fries

The aim of our study was to evaluate the influence of different heat treatment methods on trans fatty acids content in French fries. French fries were heat-treated by using a deep fryer, a frying pan, an oven and a microwave. The fatty acids content was analyzed by high-resolution capillary gas chromatography using MS detector (GC/MS). The highest increase in fat was determined in French fries prepared in deep fryer in comparison to raw French fries, whereas the lowest by using oven and microwave. We found that frying French fries in deep fryer causes the decrease in saturated fatty acids content, the increase in monounsaturated and polyunsaturated fatty acids. The trans fatty acids level in raw and heat-treated French fries was low (<0,30% of all fatty acids). The results of our study have shown that there is no significant influence of short-time heat treatment on trans fatty acids content i French fries.