Physicochemical changes of olive oil and selected vegetable oils during frying

The performance of olive oil during intermittent frying of potato slices and cod fillets was compared to those of selected vegetable oils (corn, olive-residue and 50/50 mixture of olive and corn oils) using conditions resembling those used in home food preparations. The main scope of this study was to decide what is the best substitute for olive oil in home frying applications. Free fatty acid content, peroxide value, polar compounds, color and viscosity were increased, whereas iodine value, polyunsaturated fatty acids content and tocopherol concentration decreased. The organoleptic quality of potato slices and cod fillets fried in all oils was determined. Significant differences in the physicochemical changes were observed. The analytical and sensory data showed that the lowest deterioration occurred in olive oil and the highest in corn oil. The 50/50 (w/w) olive/corn oil mixture proved to be a good substitute for olive oil in domestic frying applications.