Vegetable Oils and Fats: Extraction, Composition and Applications

Lipids contain a broad category of non-polar molecules that are barely soluble or completely insoluble in water, but soluble in chloroform, hexane, methanol and diethyl ether. The main sources of edible lipids are from the agricultural origin, mainly extracted from fruits, seeds or fish. They are found in the form of free or bound fatty acids, phospholipids, waxes, sterols, tocopherols, carotenoids, cholesterol and similar compounds. Oilseeds and fats production requires several unit operations, starting with a pre-treatment stage that includes washing, drying, heating and flaking followed by a processing stage, dependent on the type of raw material and the target product, using different techniques alone or combined such as rendering, pressing and solvent extraction. Crude fat and any other soluble material can be co-extracted in addition to lipids. These may include residual moisture, pigments, carotenes, urea and other compounds. The final stage concerns purification the obtained oils via multiple operations which involve refining, bleaching, destearinating or winterizing, hydrogenation and deodorization. In the last decade, oilseeds and fats have witnessed the extension of their application range from edible food towards new applications. Nowadays, they are included in many preparations of a large range of cosmetics, functional ingredients or nutraceuticals and recently have made the breakthrough as synthons and greener solvent options as described later in this chapter.