Physicochemical Analyses of Bovine Milk Fat Globule Membrane. I. Differential Thermal Analysis

Abstract

Freeze-dried milk fat globule membrane contained 63% by weight lipids of which 68% were tHglycerides and 14% phospholipids. Diglycerides, monoglycerides, cholesterol, cholesteryl esters, free fatty acids, and pigments were also present. Differential thermal analysis of the membrane preparation and of various fractions isolated therefrom, revealed pronounced thermal transitions from melting of the triglyceride components. Thermal characteristics of the isolated phospholipids were also examined, but transitions from these components could not be detected in the intact membrane because of the dominant thermal effects from triglycerides. Fat globule membrane underwent an irreversible endothermic transition near 80 C which is of interest in relation to the pasteurization of cream.