Sterols, Stanols, and Waxes

Abstract

AbstractPhytosterols (plant sterols and stanols) and waxes are a part of the minor components of vegetable fats and oils. Stanols are the saturated form of plant sterols. Phytosterols (PS) are isoprenoid derivatives, which are essential compounds of biological membranes. They are structurally similar to cholesterol and control fluidity of eukaryote membranes and have role in the synthesis of hormonal sterols. PS are a major part of the unsaponifiable fraction of vegetable oils. They can be found either in free or esterified forms. PS are classified into three groups according to the presence or absence of methyl group at their C4 position, namely desmethylsterols (without methyl group), monomethylsterols (with one methyl group), and dimethylsterols (with two methyl groups). Generally, desmethylsterols comprise a high proportion of PS. PS have antioxidative properties and also can be used in vegetable oil authenticity. Consumption of PS through diet has beneficial effects on human health, such as lowering of LDL cholesterol and prevention of various types of cancers. However, PS like other lipids can be oxidized, and their oxidation products are important from the nutritional point of view. Waxes naturally occur in vegetable oils. They are present in saponifiable fraction and can be removed with dewaxing/winterization process, which is necessary in salad oils. Waxes have different edible and nonedible applications. This article reviews plant sterols, stanols and waxes structure, content in vegetable oils, changes in the effects of various processes, applications, analytical aspects, and future prospects.