Oxidation of lipids in fish meal

Oxidation of lipids in fish meal has been studied. The course of the reaction has been followed by means of oxygen absorption, peroxide values and chromatographic analyses. The latter has been used quantitatively, because the method of methylation of the unreacted fatty acids obtained by hydrolysis of the glyceryl esters has proved to the quantitative. The results indicate: (a) there are other oxygen‐consuming reactions which account for up to 10 times the oxygen consumed by simple peroxidation of the polyunsaturated lipids; (b) increasing moisture content has a marked prooxidant effect in all the oxidative reactions; (c) the overall rate of reaction is apparently independent of the peroxide concentration in the lipid, possibly due to the fact that there is some resistance to the diffusion of oxygen which produces deviations from the normal autocatalytic path of the reaction occurring when oxygen is fully available.