ABSTRACT
It is well known that whatever their kind and origin, fats and oils have a limited stability. During storage, they undergo various deteriorative reactions that reduce their nutritive value and also produce volatile compounds, giving off unpleasant smells and tastes. In general, the term rancidity has been used to describe the different mechanisms by which lipids alter in nature, mechanisms that may have a biological or chemical origin. Among the alterations of a biological nature, there are those produced by microorganisms (bacteria, fungi, yeasts), which may be inhibited by the addition of preservatives, and those produced by enzymes, mainly hydrolytic rancidity or lipolysis. The latter may be inhibited by thermal treatment, by conservation at low temperature, or by reducing the percentage of water.
