Among the browning reaction of various foods, the Maillard reaction has been studied extensively and it is known that the reaction products show strong antioxidative activity, while on the discoloration of autoxidized oil, the detailed reaction mechanism has not been explained.
This paper deals with the antioxigenic effect of the browning products of autoxidized oil and several amino compounds, and the difference of the reactions between the Maillard reaction and the discoloration of autoxidized oil were also discussed.
The acetone-soluble fractions of several model systems (Table 1) were examined, after incubation at 78°C, 10 hours, for antioxigenic effect (Fig. 1), reducing activities, nitrogen contents (Table 2) and IR absorption spectra (Fig. 2-5).
As the result, only the water-soluble fraction of autoxidized oil and the amino acid system (WS-AA) showed remarkable antioxigenic effects and reducing activity out of autoxidized oil systems. In regard to nitrogen content, WS-AA system was higher than the other autoxidized oil systems and nearly equal to that of the Maillard reaction. In another of the autoxidized oil systems, the most important reaction in the discoloration of fisheries products showed no antioxidative activity and a low nitrogen content. These results suggested that in the browning of autoxidized oil, the reaction of the water-soluble fraction with amino acid is similar to the Maillard reaction, but the reaction with ammonia is different from the former.