Composition of Molecular Distillates of Butter Oil: Isolation and Identification of Components Other than Glycerides.

Molecular distillates of butter oil consisting of the four most volatile 2.5% cuts (obtained by a redistillation of the first 10% cut), the next most volatile 40% cut, and the 50% residue obtained from 777 pounds of oil were subjected to fractionation by adsorption and gas-liquid chromatography. Only the most volatile 2.5oj, cut, which contained 10% unsaponifiable matter, was examined in detail. I t consisted of 9% sterol, 740/, triglyceride, 7% diglyceride, 4y0 monoglyceride, 5% free fatty acid, and a small amount of cholesterol esters and hydrocarbons. Of the unsaponifiable material, which represented 56% of the total unsaponifiable lipid present in the original oil, about 89% was sterol, 6.3y0 hydrocarbon, and 1 .2y0 carbonyl material, the rest being made up of unidentified compounds of varying polarity. Ninety-five per cent of the total sterol was free cholesterol. The hydrocarbon fraction was a complex mixture of the C17 to odd and even carbon number hydrocarbons of the normal, iso, and 1-cyclohexyl (?) series. Although a number of these hydrocarbons were unsaturated. only squalene could be positively identified. The distribution of the fatty acids in the various lipid classes was markedly different from that of the original butter oil. The fatty acids of the cholesterol esters were particularly rich in the minor acids of butter fat. The small carbonyl fraction was not fully examined.