Abstract
Deep-frying oil properties of diacylglycerol-rich cooking oil (DG oil) were examined so as to assess the extent of thermally oxidative deterioration. The results obtained were compared with those for triacylglycerol-rich oil (TG oil). Autoxidation of DG oil at 50°C was much slower compared to TG oil. The viscosity of DG oil exceeded that of TG oil and both these parameters increased with the heating of either oil. Acid value (AV) of fresh DG oil (0.49) was higher than that of TG oil (0.11). AV, carbonyl and p-anisidin values of DG and TG oil increased with the number of uses. It follows from the present findings that the thermal oxidation of DG oil during deep-frying is basically the same as that of TG oil.
