The effect of wax addition on oil absorption and some quality parameters of frying oil

Sunflower seed oil is one of the most commonly used oil in frying processes. The oils used for frying are absorbed by the fried materials in it. The most important factors affecting the oil absorption are counted as temperature, time, pretreatment and addition of various ingredients. In addition, the frying process affects the quality parameters of oils such as peroxide value, color and free fatty acids. Response surface methodology (RSM) was applied to model and optimize frying conditions: time (2-10 min), temperature (150-180 °C) and wax content (%0-1,5). The moisture content of fried potatoes was also followed as response together with oil absorption. The frying conditions determined with modelling at the lowest oil absorption (%9) and moisture content of potatoes (%29) were found as time 9 min, temperature 152 °C and wax content (%1,5). Experimental oil absorption at optimum conditions defined by modelling was found as %9,2 and this value was very close to the theoretical value. Oil absorption in potatoes fried in sunflower oil without waxes was %10,2 . Peroxide values recorded during 5 days and 10 times in each day of frying process at optimum conditions were lower in oils containing wax (10,6 meq/kg oil) compared to the oils not containing wax (21,2 meq/kg oil) by the end of 50 frying. However, free fatty acids, color values and fatty acid compositions had a similar trend for both of the oils containing wax or not and the change was not significant (p<0.05) throughout the frying process.