ABSTRACT
Figure 8.1 Molecular structure of the major glycerophospholipids in dairy products. The fattyacid residues are taken arbitrarily. (From Rombaut, R., Enrichment of nutritionally advantageous milk fat globule membrane fragments present in dairy effl uents, PhD dissertation, Ghent University, Gent, 2006. With permission.)
carbon atoms, two hydroxyl groups, and one double bond. A ceramide is formed when the amino group of this sphingoid base is linked to a saturated fatty acid. Furthermore, odd-numbered (e.g., C23:0) acyl chains can be found [6]. On this ceramide unit, an organophosphate group can be bound to form a sphingophospholipid (e.g., phosphocholine in the case of sphingomyelin [SM]) or to a sugar residue to form the sphingoglycolipids (glycosylceramides). Monoglycosylceramides, like glucosylceramide or galactosylceramide, are often referred to as cerebrosides. Finally, gangliosides are highly complex oligoglycosylceramides, containing one or more sialic acid groups in addition to glucose, galactose, and galactosamine. e major sphingolipids in dairy products, glucosylceramide (GluCer), lactosylceramide (LacCer), and SM, are represented in Figure 8.2.
