VALIDATION OF THE RANCIMAT TEST FOR THE ASSESSMENT OF THE RELATIVE STABILITY OF FISH OILS

The induction periods for the peroxidation of various fish oils at 55- 90 degrees C were studied by the Rancimat test. The natural logarithms of the induction periods varied linearly with respect to temperature, with a mean coefficient of -7.5 x 10(-2) degrees C-1, which was signi ficantly different from that reported for vegetable oils. The activati on energy for the formation of volatile acids had a mean value of 38.9 kJ/mol and was independent of the fish oil source. Peroxide formation under Rancimat test conditions followed first-order kinetics. The sam e kinetics were followed under Schaal Oven test conditions (forced-air oven, 60 degrees C). On the basis of the results obtained, the Rancim at test appears to be useful in determining the relative stabilities o f fish oils without the change in peroxide decomposition kinetics that may occur at elevated temperatures.