ABSTRACT
In industrial and commercial understanding, the term lecithin denotes a complex mixture of neutral lipids, polar, and carbohydrates. Two main classes of phospholipids occur naturally in amounts that have led to industrial applications: phosphoglycerides and phosphosphingolipids. The exclusive sources of vegetable phospholipids are commercial lecithins obtained in the first step of vegetable oil refining during the degumming process. The molecular structure of phospholipids can be changed by either enzymatic or chemical means. The aim of all these processes is to obtain tailormade technological and physiological properties that are somewhat different from those of the natural substances themselves. Phospholipids are well recognized natural ingredients in cosmetics as they combine a long list of positive properties that are of special attraction to the cosmetic formulator. Liposomes are tiny globular vesicles. An aqueous cave is entrapped inside a structure of one to several double layers of phospholipids. In so-called multilamellar liposomes each double layer is separated from the other by an aqueous compartment.
