Characteristics of High-Melting Triglyceride Fractions from the Fat-Globule Membrane and Butter Oil of Bovine Milk

A high-melting triglyceride fraction (HMGF) was isolated from an alcohol-ether extract of the fat-globule membrane and from an ethanol extract of butter oil. The HMGF was characterized by its iodine value (4.8-5.0), saponification equivalent (200)(201)(202), and melting range (50.0-52.5 C.), and by its ultraviolet (220-340 m~), nearinfrared (1.6-3.1 /z), and infrared {12-14 ~) spectra. The fatty acid composition of the fraction was determined by converting the glyceride to its constituent fatty acid methyl esters which were resolved by gas chromatography as follows: C~o-0.1, C~-0.9, C1, --11.0, Cle --59.6, Cls --16.5, C18 ~= --5.6, C,8 "~= --0.4, C1~ ~= --0.2, and unassigned components--5.8 mole %, respectively. Characteristics of the high-melting glyceride fractions obtained from the membrane and from butter oil were similar. The H~[GF constitutes the triglyceride content of the membrane.