Influence of dimethylpolysiloxane addition to edible oils: dependence on the main variables of the frying process

Abstract

Experiments were carried out in the absence of food to define the influence of significant variables of the frying process, i.e. oil unsaturation, temperature, surface-to-oil volume ratio, type of heating and dimethylpolysiloxane (DMPS) addition. Special emphasis was placed on clarifying the action of the addition of low concentrations of DMPS to frying oils. From statistical evaluation based on the content of polar compounds, the strong influence of the variables surface-to-oil volume ratio, DMPS addition and oil unsaturation was deduced. However, changes due to 10ºC difference in temperature were not significant. Analysis of two-way interactions demonstrated that interactions between type of heating/DMPS addition, type of heating/oil unsaturation, surface-to-oil volume ratio/DMPS addition and surface-to-oiI volume ratio/oil unsaturation were significant, thus indicating the complexity of the frying process. Finally, it was found that increase in specific groups of compounds formed through oxidative polymerization as well as loss of natural antioxidants depended mainly on the total content of polar compounds and, at a second level, on the oil unsaturation.