SUMMARY Studies were made of the distribution of tocopherol between the lipid in the fat globule membrane and inside the milk fat globule, and the relation of that distribution to the loss of tocopherol during lipid oxidation. Two fractionation procedures were used, one based on churning of cream, the other on washing cream by repeated dilution with sucrose‐saline solution and separation, followed by treatment with sodium deoxycholate. The tocopherol concentration was at least three times higher in the lipid of the fat globule membrane than inside the fat globule. During lipid oxidation, the tocopherol associated with the fat globule membrane was lost more rapidly. The results demonstrated that, in determining the oxidative stability of milk, the membrane tocopherol is more important than that inside the fat globule.

The development of rancidity in soybean oil has been studied by gas chromatography (GC), peroxide value (PV) and sensory evaluation. The GC method has been adapted from previous methodology and another type of column packing has been used for the purpose. The GC peaks have been treated as one whole group, and and oxidation value (OV) has been computed by means of an internal standard (n‐octanol). The OV’ have been correlated with the PV’s. The flavor of soybean oil and a blend of 50% soybean oil and 50% hydrogenated soybean oil, both kept at 60 C for varying lengths of time, was evaluated by a panel and the results have been presented in a new graphical form. A relationship between the OV and the flavor of the fat has been demonstrated. The merits of the method are discussed.

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