The Chemistry of Oils and Fats and their Extraction and Refining Processes [A Química dos óleos e Gorduras e seus Processos de Extra o e Refino]

Fats and oils, both in their raw form or chemically modified, have been used by humans for thousands years for different purposes, such as illumination, paints, soaps, etc. Mainly because of economic reasons, during the XXth century fatty materials were replaced by petroleum derived chemicals in several fields. Nonetheless, in the last decade, oil chemistry has emerged as an elegant alternative to fossil raw materials to produce a wide number of products, such as polymers, fuels, inks and lubricants. This paper discusses fats and oils sources, as well as their main chemical components and the effect of these chemicals in their physico-chemical and organoleptic properties. The main methods to obtain fats and oils from animal and vegetal sources are also discussed. It is described the rudimentary method used since immemorial times and that is still used in remote areas as well as the modern technologies involving press and solvent extraction and purification of fats and oils.