Carotenoids classification

Table 7.1. Classification of fruit carotenoids (Goodwin and Britton 1988)...

A. Cichelli and G.P. Pertesana, High-performance liquid chromatographic analysis of chlorophylls, pheophytins and carotenoids in virgin olive oils chemometric approach to variety classification. J. Chromatogr.A 1046 (2004) 141-146. 

To enable the utilization of the full spectral range for classification also in carotenoid-rich species, we propose a method for photodestruction of carotenoid pigments in pollen using 633 nm light. In initial experiments that were conducted at 633 nm excitation, we observed that the bands ascribed to carotenoid molecules were not stable but diminished steadily, even at relatively low excitation intensities of 10 mW. Figure 4.6 displays spectra of horse-chestnut pollen excited with 633 nm as a function of exposure time to the laser. The irreversible decrease of the intensities of the typical carotenoid bands suggests the photodestruction of these molecules (see arrows in Fig. 4.6) [72-74]. With excitation at 785 nm, the spectra of the pollen remained unal-... 

As evidenced by these data, the impact of the carotenoid features on the classification results is remarkable. Photodestruction of the carotenoid components is an efficient alternative to omitting all spectral regions where carotenoid bands may superimpose other features the latter being proposed, e.g. in studies on microorganisms [61]. The width of some of the carotenoid bands would force us to discard numerous important other spectral features hidden beneath the intense carotenoid signals. 

Among the several vitamins in this classification, only vitamin A is present in appreciable quantity as carotenoid provitamin A in citrus (38). No vitamin D has ever been reported in citrus nor any plant vitamin D precursors, such as ergosterol. Several of the sterols present in citrus fruits are reported (39, 40, 41), but they are not related to vitamin D. 

If that does occur, then the present system of classification of oils may be impossible to police, and a modified system may become necessary. Perhaps the sale and perceived value of oils will necessarily become dependent on the performance, not the source of the oil. With bulk oils such as palm, peanut, sunflower, safflower, sesame, soya, rapeseed, com, fish, and animal fats and oils, the fatty acid composition will obviously be important for health reasons. If the oil is to be used for frying then the frying properties will be important. In the case of palm products the physical properties and minor components such as carotenoids will be defined. Similarly animal fats will be judged mainly on physical behaviour and effect on the product in which they are used. In all cases the oxidative and stability of the oil will have to be defined. Sesame is a very stable oil, and thus its stability, together with its low level of linolenic acid, would be its major attribute, except for toasted sesame, which would probably be classed as a specialist oil. Already most baking fats sold to the public are blends developed to give the best performance, with no mention on the pack as to the source. If a bulk oil of this type had the desired chemical composition, stability and cooking behaviour, then perhaps the source would not be a matter of concern. 

This concept allows the classification of molecules such as carotenoids, lipophilic vitamins, steroids, terpenes etc, as lipoids . Most researchers consider those molecules as separate groups and confine the term lipid to fatty acids, their derivatives and to substances that are closely related to their synthesis and function [1,2],... 

Classification of CD Spectra of Carotenoids Sturzenegger et al. Helv Chim Acta 63 1074 1980. 

In Part I the choice of the most suitable system of classification posed a problem. The two different solutions adopted, one based on structural relationships (monoterpenoids and carotenoids) and the other on biogenetic relationships (sesqui-, di- and tri-terpenoids) in part reflects current practice. 

Fig. 7.2 Classification and structure of carotenoids (a) lycopene - acyclic hydrocarbon (b) 7-carotene - monocyclic hydrocarbon (c) /3-carotene - bicyclic hydrocarbon (d) lutein - bicyclic xanthophyll.

The generic name terpene was originally applied to the hydrocarbons found in turpentine, the suffix ene indicating the presence of olefinic bonds. Each of these materials contain two isoprene units, hence ten carbon atoms. Related materials containing 20 carbon atoms are named as diterpenes. The relationship to isoprene was discovered later, by which time the terms monoterpene and diterpene were well established. Hence the most basic members of the family, i.e. those containing only one isoprene unit, came to be known as hemiterpenoids. Table 1.1 shows various sub-divisions of the terpenoid family based on this classification. It also shows two specific sub-groups of terpenoid materials, namely, the carotenoids and the steroids. Steroids and carotenoids are sub-groups of the triterpenoids and tetraterpenoids, respectively, as will be explained later. 

Lipids are defined as water-insoluble compounds extracted from living organisms by weakly polar or nonpolar solvents. The definition is based on a physical property in contrast to the definitions of the other basic building blocks in this chapter (proteins, carbohydrates, and nucleic acids), which are based on chemical stracture. Consequently the term lipid covers a stmcturally diverse group of compounds including/afiy acids, glycerolipids, sphingolipids, terpenes, steroids, and carotenoids. There is no universally accepted scheme for their classification. 

Classification Carotenoid pigment Definition Carotenoid pigment found mostly in animai organsims, but aiso occurring in plants Empirical C40H62O4... 

Classification Carotenoid pigment Definition A precursor of Vitamin A occurring naturally in plants Empirical C40H56... 

CAS 7235-40-7 EINECS/ELINCS 230-636-6 Synonyms p-Carotene Food orange 5 Synthetic carotene Classification Carotenoid color Empirical C40H56 Toxicology TSCA listed Uses Colorant in cosmetics, pharmaceuticals Manuf./Distrib. Aldrich http //www.sigma-aldrich.com, Fluka http //www.sigma-aldrich.com, Sigma See aiso Carotene Cl 75130... 

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