Actually the term lecithin connotes two meanings that are somewhat related but are not used in the same sense. In biochemistry and other related science, lecithin is a synonym for phosphatidyl choline. It is the main lipid component in biological membranes, like our cell membranes or cell walls of plants. On the other hand, commercial lecithin is actually a natural mixture of neutral and polar lipids, including glycolipids, triglycerides, sterols, and small quantities of fatty acids, carbohydrates, and sphingolipids. The polar lipid Phosphatidyl choline is present in commercial lecithin in concentrations of 20 to 90%.
