Comparison of the Frying Stability of Sunflower and Refined Olive Pomace Oils With/Without Adsorbent Treatment

The aim of this study was to compare the frying behaviors of refined olive pomace (ROP) oil to sunflower oil in a 5-day trial, and to evaluate the refresh capacity of a new adsorbent mixture composed of diatomaceous earth, zeolite and lime. Frying trials were performed as control and adsorbent-treated groups. Oil samples collected after each day of frying were analyzed for physical characteristics (viscosity, turbidity, refractive index, smoke point), color values (L, a* and b*), and chemical properties (free acidity, peroxide value, conjugated dienoic acids, total polar materials). The amount of oil absorbed by the fried dough was measured. In general, results indicated that ROP oil had higher thermal stability. There were no significant differences between the quality parameters of control and adsorbent treated samples for either oil sample. Effectiveness of the new adsorbent mixture on frying oil refreshing was limited only to free acidity, viscosity, and color. Total polar materials measured with probe sensor were determined to be as accurate as the official technique, and can be recommended for quick, easy and cheap analysis. Also, there were some significant correlations between the measured oil quality parameters.