ABSTRACT
In the scientific and even professional literature, the term lipids is more and more widely used. Lipids are classes of fatty acid derivatives. Their nomenclature is defined by the joint IUPAC-IUB standard (1). Fatty acids (aliphatic monocarboxylic acids) of 4 and more carbon atoms are usually bound as esters in plant and animal tissues, and only rarely as amides or free acids. Triacylglycerols, waxes, phospholipids, glycolipids, mucolipids, and lipoproteins
are the most important lipid representatives. For many authors, especially in medical or biological sciences, lipids are exclusively naturally occurring fatty acid derivatives, but this definition is not useful for food science and technology because many closely related compounds, such as hydrogenated oils, structured lipids, fatty acid methyl or ethyl esters, and many oleochemicals do not occur in nature, but have been produced industrially. Aliphatic fatty acids are not the only organic acids bound in lipids because alicyclic or even phenolic acids were detected in natural lipids.
