Influence of dimethylpolysiloxane addition to frying oils: performance of sunflower oil in discontinuous and continuous laboratory frying

Conventional and high oleic sunflower oils were used to study the influence of dimethylpolysiloxane (DMPS) addition (2 mg/Kg) on discontinuous and simulated continuous laboratory frying. Analytical methods applied for a direct evaluation of oil degradation included determination of total polar compounds, polymers, oxidized triglyceride monomers and diglycerides. Results indicated that DMPS has a strong positive action in discontinuous frying as differences between samples with and without DMPS were very high and much more pronounced than those attributed to oil unsaturation. However, DMPS was not effective in simulated continuous frying. Comparison from results obtained for discontinuous and simulated continuous frying demonstrated that the surface was well protected from the penetration of oxygen when potatoes are being fried and, in consequence, protection by DMPS in discontinuous frying took place when the oil surface was unprotected