Carotenoids in foods

HART J D and SCOTT K J (1995) Development and evaluation of an HPLC method for the analysis of carotenoids in foods and the measurement of carotenoid content of vegetables and fruits commonly consumed in the UK. Food Chem. 54(1) 101-111. 

In general, carotenoids in foods are C40 tetraterpenoids comprised of eight C5 isoprenoid (ip) units (Figure 2.2.2) whose order is inverted at the molecule center, joined head to tail, except at the center where a tail-to-tail linkage reverses the order, resulting in a symmetrical molecule. This produces the parent C40 carbon skeleton from which all the individual variations are derived. ... 

Carotenoids in Foods Sources and Stability during Processing and Storage... 

The different levels of carotenoids in foods reported in the literature may simply arise from the use of different items and/or varieties since the same common names are sometimes applied to items with different scientihc names. To overcome this... 

The comparison of the light effect on carotenoids in foods is very difficult to carry out because different foods with different isomer compositions are employed at the beginnings of experiments. The presence of large molecules offers some photoprotection to carotenoids in food systems, either by complexation with proteins as found in carrots or acting as a filter to reduce the light incidence. Different storage conditions are often found because different light intensities are used or sometimes they are not even reported and experiments are carried out under air, N2, or in a vacuum. 

An alternative for evaluating accuracy is spiking known amounts of standards to a food, as reported in several papers,although percent recoveries of spikes do not truly address the influence of the food matrix complexity on the extraction efficiency. Data evaluation procedures were developed as a manual system to assess the quality of analytical data for carotenoids in foods. ... 

Scott, K. et al.. Interlaboratory studies of HPLC procedures for the analysis of carotenoids in foods. Food Chem., 57, 85, 1996. 

Mercadante, A. Z. 2008. Carotenoids in foods Sources and stability during processing and storage. In Food Colorants Chemical and Functional Properties, ed. C. Socaciu, pp. 213-240. Boca Raton, FL CRC Press. 

Partali, V., Liaaen-Jensen, S., Slagsvold, T., and Lifjeld, J. T. 1987. Carotenoids in food chain studies. II. The food chain of Pams spp. monitored by carotenoid analysis. Comp. Biochem. Physiol. B 87 885-888. 

Rodriguez-Amaya DB. 1993. Nature and distribution of carotenoids in foods. In Charalambous G, editor. Shelflife Studies of Foods and Beverages. Chemical, Biological, Physical and Nutritional Aspects. Amsterdam Elsevier Science, pp. 547-589. 

Chlorophylls occur very frequently in the plant kingdom, they are responsible for the colour of vegetables and some fruits. They also occur in algae and several bacteria. Chlorophylls in plants are photoreceptors and in photosynthesis the presence of a closed circuit of conjugated double bonds allows them to absorb light. Because of their predominant importance as photoreceptors a considerable number of analytical methods have been developed for the separation and quantitative determination. The analytical methods applied for the measurement of chlorophylls and carotenoids in food products have been reviewed previously [273],... 

Phases of extended length (C30) have been utilized for the separation of larger-size constrained solutes, such as carotenoids and steroids [27-29,93,106,107]. Apractical limit of alkyl chain length of C34 to C36 is imposed by the commonly employed silan-ization chemistry techniques [106]. Immobilization of longer alkyl stationary phases has been achieved through the use of poly(ethylene-co-acrylic acid) materials for use in carotenoid separations [27,28,93]. Rimmer et al. [28] have recently compared the selectivity of both alkyl and poly(ethylene-co-acrylic acid) stationary phases on the basis of separations of carotenoids in food matrices (Figure 5.12), in addition to mixtures of tocopherols and PAHs. 

Scott, K.J. 1992. Observation on some of the problems associated with the analysis of carotenoids in foods by HPLC. Food Chemistry 45 357-364. 

Since the IU was based on studies that did not take into account the poor absorption and bioavailability of carotenoids in foods, the equivalency of retinol and /3-carotene in the IU system differs from that in the RE system. Thus in the RE system, 1 fig retinol = 6 fig /3-carotene, whereas in the IU system, 1 fig retinol = 2 fig /3-carotene. 

Table 9 HPLC Methods Used for the Determination of Provitamin A Carotenoids in Food... 

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