Composition of molecular distilates of corn oil: isolation and identification of sterol esters.

S U M M A R Y Molecular distillates of corn oil consisting of the three most volatile 1.7 per cent cuts and the next most volatile 4.9 per cent cut obtained from 150 kg. of refined oil have been subjected to simple solvent and chromatographic fractionation. These fractions represented about 10 per cent of the original oil and some 50 per cent of its total unsaponifiable material. About 74 per cent of this unsaponifiable matter was sterol, of which 75 per cent was free, the rest combined-mainly as the long-chain fatty acid esters. The remainder of the analyzed unsaponifiable matter consisted of hydrocarbons (3.3 per cent), tocopherols (15.0 per cent), material more polar than free sterols (5.0 per cent), and various other uncharacterized fractions of differing polarity (2.7 per cent). The sterol ester fraction was made up largely of the linoleates, oleates, and palmitates of betaand gamma-sitosterols and the triterpenoid alpha-sitosterols. Indications were obtained for the presence of tocopherol esters in corn oil. Among the glyceride esters the monoand diglycerides of the major corn oil fatty acids were recognized representing, respectively, 0.05 and 0.52 per cent of the original oil. The refined corn oil was estimated to contain about 0.08 per cent acidic material of which more than 90 per cent appeared in the first most volatile 1.7 per cent cut. It contained mainly oleic and linoleic acids in about the same proportion as they occur in the corn oil,