Improvement in Frying Stability of Safflower Oil by Blending with Refined Olive Pomace Oil during Deep Fat Frying

Abstract

The objective of the present study was to increase the frying stability of refined safflower oil (RSO) by blending it with refined olive pomace oil (ROPO) during deep fat frying. For this purpose; RSO, ROPO and their blends were utilized for frying of potato sticks at 180°C for 3 consecutive days. The frying stability of the oils was monitored by analyzing them for their free fatty acids, peroxide values, total polar contents, ultraviolet spectrophotometric indices at 232 and 270 nm, fatty acid profiles, p-anisidine values, α-tocopherol contents and photometric color indices. 3-monochloropropane-1,2-diol (3-MCPD) and glycidyl ester (GE) levels of oils before and after frying were measured as well. The results have shown that thermo-oxidative degradation products increased as the frying progressed for all oils, however the decomposition rate was found to slow down in blend oils by stabilizing with ROPO. Blending RSO with ROPO decreased linoleic and linolenic; but increased the oleic and palmitic acid percentages of the blends. C18:2/C16:0 ratio was found to decrease by frying for RSO and the blend oils, however ROPO was not affected significantly. 3-MCPD-E levels of the blends increased as the ratio of ROPO increased. Principal component analysis enabled a clear discrimination between oils with different composition throughout the frying process.