Rapid Method for the Quantitative Extraction and Simultaneous Class Separation of Milk Lipids

Abstract

A method is described for the isolation of lipids from milk, cream, or buttermilk. Lipid isolation is accomplished by solvent elution of a column containing a mixture of the milk product, anhydrous sodium sulfate, and Celite 545. Total lipids are isolated by elution with a 90:10 mixture of dichloromethane:methanol. Alternatively, lipids may be separated into a neutral lipid fraction by sequential elution of the column with dichloromethane and a polar fraction by elution with a 90:10 mixture of dichloromethane:methanol. The proposed method was compared with the traditional Roese-Gottlieb method for a series of milk samples with fat content ranging from<1 to 37%. Fat determinations for a series of five milk types by the dry column and Roese-Gottlieb methods were significantly different for whole raw milk and buttermilk, while means for phospholipids were significantly different for all milk types tested except buttermilk.