ABSTRACT
The milk fat globule membrane contains the phospholipids, proteins, some cholesterol, and other amphipathic components; the phospholipids are a result of de novo synthesis. Milk donors for studies at the University of Connecticut are recruited in the second and third trimester of pregnancy from practices of cooperating obstetricians. In addition, since inadequate maternal caloric intake can affect milk yield and therefore total lipid output, additional screening must be done to ensure that maternal caloric intakes are adequate. This established effect requires that all subjects be carefully screened for homogeneity of diet. Milk is extracted from the breast by manual expression, manipulation with the fingers, or a breast pump which provides a more or less gentle suction. The purpose of frozen storage is to prevent or reduce lipolysis without affecting the lipids. Most of the lipolysis of TGs in human milk is caused by bile salt-stimulated lipase, but only when bile salts are added. The other lipase is serum-stimulated lipoprotein lipase.
