Cholesterol content and lipid composition of low fat dairy products

Abstract

The lipid composition of different products obtained from the same raw milk was investigated. The cholesterol content of skim milk (0.05% total fat) and butter milk (0.57% total fat) lipids was 4.20% and 1.31%, respectively, while raw milk lipids and butter fat contained 0.34% or 0.30%, respectively. As the cholesterol content of these low fat milk products increases with decreasing fat content, equations were derived to estimate the fat-related cholesterol content from the value analysed in butter fat. In contrast to the fat-related cholesterol content, the product-related content is still relatively small in skim and butter milk. Their fat-related cholesterol content was found to be influenced by drying. The high content of phospholipids in skim and butter milk led to considerable changes in the fatty acid composition and affected the detection of foreign fat by butyric acid as well as by triglycerides. Skim and butter milk lipids contained only 2.41% or 2.33% butyric acid, respectively, instead of 3.36% found in raw milk lipids. Further, the overlap of phospholipids as well as cholesterol with the gas chromatographic triglyceride pattern resulted in calculated foreign fat contents of more than 20%.