Triacylglycerols classification

Discriminant analysis has been used in many of the analyses described in this chapter, in particular the classification of cocoa butters by origin and processing from pyrolysis MS data (Radovic et al., 1998), from triacylglycerol profiles obtained by HPLC (Hernandez et al., 1991) and from analysis of volatiles (Pino, 1992). Data from the analysis of mixtures of CBEs with cocoa butter, which model techniques for measuring CBEs in chocolate, have been treated by similar means (Anklam et al., 1996). 

While an optical classification of triacylglycerols could be made, confusion arose over the two primary alcohols. 

During natural evolution, a broad variety of enzymes has been developed, which are classified according to the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (IUBMB). Thus, for each type of characterized enzyme an EC (Enzyme Commission) number has been provided (see http // www.expasy.ch/enzyme/). For instance, all hydrolases have EC number 3 and further subdivisions are provided by three additional digits, e.g. all lipases (official name triacylglycerol lipases) have the EC number 3.1.1.3 and are thus distinguished from esterases (official name carboxyl esterases) having the EC number 3.1.1.1. This classification is based on the substrate (and cofactor) specificity of an enzyme only, however often very similar amino acid sequences and also related three-dimensional structures can be observed. 

Cholesterol, which is largely insoluble in aqueous m a, travels through the blood circulation in the form of Upoprotein complexes. The plasma lipoproteins are a family of globular particles that share common structural features. A core of hydrophobic lipid, principally triacylglycerols (triglycerides) and cholesterol esters, is surrounded by a hydrophilic monolayer of phospholipid and protein (the apolipoproteins) [1-3]. Lipid-apolipoprotein interactions, facihtated byi amphi-pathic protein helices that segregate polar from nonpolar surfaces [2,3], provide the mechanism by which cholesterol can circulate in a soluble form. In addition, the apolipoproteins modulate the activities of certain enzymes involved in Upoprotein metabolism and interact with specific cell surface receptors which take up Upopro-teins by receptor-mediated endocytosis. Differences in the Upid and apoUpoprotein compositions of plasma Upoproteins determine their target sites and classification based on buoyant density. 

Ruiz-Samblas, G. Guadros-Rodriguez, L. Gonzalez-Casado, A. Rodriguez Garcia, F.D.P de la Mata-Espinosa, P. Bosque-Sendra, J.M. (2011). Multivariate analysis of HT/GC-(IT)MS chromatographic profiles of triacylglycerols for classification of olive oil varieties. Analytical and Bionalytical Chemistry, Vol.399, No.6 (February 2011), p>p. 2093-2103, ISSN 1618-2642... 

Lipids are present as ingredients in most foods and play key nutritional roles, being crucial for many physiological functions, they also can be used as food quality markers. For these reasons, the characterization of the lipid fraction present in fats and oils is important for the food industry. Following a general lipid classification, triacylglycerols (mono- and diderivatives), phospholipids, glycolipids, waxes, and sterol esters are included in the saponifiable fraction, whereas the nonsaponifiable... 

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