27. The Autoxidation of Butterfat: I. Factors Influencing the Reaction

Abstract

The influence of a number of factors on the autoxidation of butterfat has been studied. Metallic catalysts have been found to exert a great effect in hastening the reaction, their intensity being in the following decreasing order: sodium vanadate, copper lactate, iron lactate, nickel sulphate. Zinc lactate has a slight retarding action. Ultra-violet light, hydrogen peroxide and fat peroxides have a strong prooxidative effect and to a less extent lactic acid. Curd exerts an antioxygenic effect, while humidity, glycerol, triolein, lactose, iodine, potassium iodide and the effect of pasteurisation have little or no influence. The author wishes to thank the Auckland University College Council and Sir James Gunson for a Sir James Gunson Scholarship during the tenure of which this research was undertaken, Dr F. H. McDowall for his helpful interest in the work, and the Dairy Research Institute (N.Z.) for permission to work in their laboratories.