Lipid Composition of Vegetable Oils

Abstract

Publisher Summary This chapter provides an overview of lipid composition of vegetable oils. Fatty acids present in free or bound forms in vegetable oils usually have straight chains, an even number of carbon atoms, and are monocarboxylic; odd-numbered acids occur rather rarely and occur always in trace amounts. Branched-chain fatty acids have not yet been found in vegetable oils, but unusual fatty acids having acetylenic, cyclopropenic, and hydroxy groups or conjugated double bonds are sometimes important constituents of seed oils. The fatty acid composition of seed oils is characteristic of the plant source; nevertheless, variations, because of climatic or seasonal conditions, are often observed. Saturated and unsaturated acids, such as palmitic, stearic, palmitoleic, oleic, linoleic, and linolenic, are the major components of common seed oils; other saturated and unsaturated acids are often present as major or minor components. Sometimes in specific seeds, unusual fatty acids predominate; the component acids of seed fats could themselves be a basis for a classification of plants. The chapter describes the composition of some of the most common seed oils. Vegetable oils are mainly triglyceride mixtures resulting from the incorporation of component acids of seed fats, according to genetic rules, into the three positions of the glycerol molecule. Vegetable oil fatty-acid analysis has been greatly advanced by the application of spectroscopy and spectrometry. Today, research on the components of most different lipid types, vegetable oils included, is in full development; from it, the solution of many problems in the medical–biological field and improvements in industrial applications can be expected.