Carotenoids sources

FIGURE 2.2.2 Structure of carotenoid (Source Adapted from Goodwin, T.W., Biochemistry of the Carotenoids, Chapman Ffall, New York, 1980.)... 

Figure 6-21 Relationship Between Crocin and Picrocrocin and the Carotenoids. Source From E.C. Grob, The Biogenesis of Carotenes and Carotenoids, in Carotenes and Carotenoids, K. Lang, ed., 1963, Steinkopff Verlag.

Figure 6-22 Structure of Some of the Important Carotenoids. Source From B. Borenstein and R.H. Bunnell, Carotenoids Properties, Occurrence, and Utilization in Foods, in Advances in Food Research, Vol. 15, C.O. Chichester et al., eds., 1967, Academic Press.

Serum levels of total carotenoids in the absence of retinol levels are not useful for assessing vitamin A status of individuals or populations because they reflect the level of immediate dietary intake (Clausen and McCoord, 1938 WHO, 1976, 1982). Furthermore, as shown in Table IX, as much as two-thirds or more of the total carotenoids may be non-vitamin A-active compounds (Buzina etaL, 1971). The seasonal effect of carotenoid intake on plasma vitamin A and carotenoid levels is illustrated in Fig. 4. An exception may be among populations, especially children, where malnutrition is prevalent and essentially all the dietary vitamin A throughout the year comes from carotenoid sources (Le Francois et aL, 1980). In this special circumstance when dietary sources of both vitamin A and carotenoids are low, a low carotene value in blood is evidence for inadequate vitamin A status. But in the absence of a serum vitamin A level, a low carotene level may reflect either an inadequate amount in the diet or malabsorption, and without additional supportive evidence cannot be interpreted to reflect poor vitamin A status (Arroyave et al., 1982). 

A system containing 20% of a tertiary alcohol in petroleum ether separated all the investigated pigments except -carotene and lycopene. A typical separation is shown in Fig. 12, where an extract from parsley was used as the carotenoid source, and the efficient spread of the polar pigments is evident. The separations are even better on plastic-backed silica gel (0.2 mm, Merck), where extremely narrow bandwidth can be produced. Combined with circular TLC, the system provides valuable information about samples with complicated pigment patterns in the polar area. 

Egg yolk and shell colours are important aspects of egg quality in many countries. Egg yolk pigmentation is a complex process influenced by many factors, such as nutrition, carotenoid source, health, egg handling and storage. Egg yolk contains as the main pigments the same xanthophylls and carotenes that occur in the depot fat of hens. The most abundant pigment is lutein/zeaxanthin, followed by p-cryptoxanthin and -carotene and other carotenes occurring in the feed (such as canthaxanthin and P-apo-8 -carotenal). The amount of p-carotene is low (0.3 1% of total carotenoids), as this carotene is quickly metaboKsed. 

Natural Carotenoids (or Nature-Identical Forms) and Rich-Carotenoid Sources Listed by the Food and Drugs Administration (FDA) for Food and Beverage Use... 

Recently, Homero-M6ndez and Mmguez-Mosquera (2000) highlighted an alternative carotenoid source in Rosa mosqueta hips. Six major carotenoids were identified. The average composition was estimated as 497.6 mg/kg P-carotene, 391.9 mg/kg lycopene, 703.7 mg/kg rubixanthin, 289.2 mg/kg gazaniaxanthin, 183.5 mg/kg P-cryptoxanthin, 266.6 mg/kg zeaxanthin, and 67.1 mg/kg minor carotenoids (dry-weight basis). 

Hornero-Mendez, D and Mmguez-Mosquera, MI (2000) Carotenoid pigments in Rosa mosqueta hips, an alternative carotenoid source for foods. 7. A nc. FoodChem.,4S, 825-828. 

Rich sources of vitamin A include dairy products such as milk cheese, butter, and ice cream. Eggs as well as internal organs such as the Hver, kidney, and heart also represent good sources. In addition, fish such as herring, sardines, and tuna, and in particular the Hver oil from certain marine organisms, are excellent sources. Because the vitamin A in these food products is derived from dietary carotenoids, vitamin A content can vary considerably. Variation of vitamin A content in food can also result from food processing and in particular, oxidation processes (8). 

Fertile sources of carotenoids include carrots and leafy green vegetables such as spinach. Tomatoes contain significant amounts of the red carotenoid, lycopene. Although lycopene has no vitamin A activity, it is a particularly efficient antioxidant (see Antioxidants). Oxidation of carotenoids to biologically inactive xanthophyUs represents an important degradation pathway for these compounds (56). 

Many carotenoids function in humans as vitamin A precursors however, not all carotenoids have provitamin A activity (Table 3). Of the biologically active carotenoids, -carotene has the greatest activity. Despite the fact that theoretically one molecule of -carotene is a biological source of two molecules of vitamin A, this relationship is not observed and 6 p.g -carotene is equivalent to 1 p. vitamin A. Although -carotene and vitamin A have complementary activities, they caimot totally replace each other. Because the conversion of -carotene to vitamin A is highly regulated, toxic quantities of vitamin A cannot accumulate and -carotene can be considered as a safe form of vitamin A (8). 

Although the carotenoids can be obtained from natural sources, it is far more economical to manufacture them for commercial use (130). Three have been manufactured for many years -carotene [7235-40-7] (42), canthaxanthin [514-78-3] (43), and P-apo-8 -carotenal [1107-26-2] (44) (131). Their stmctures are shown ia Figure 1. 

Retinoids are alcohols and accordingly soluble in ethanol, isopropanol, and polyethylenglycol. Major sources of natural retinoids are animal fats, fish liver oil (retinylesters) and yellow and green vegetables (carotenoids). Ingested retinylesters (RE) are hydrolyzed to retinol by enteral hydrolases in the intestine. ROL and carotenoids are absorbed by intestinal mucosa cells. 

Factors affecting carotenoid bioavailability food sources and intakes... 

Table 7.1 Common dietary sources of carotenoids in regular vegetable foods, xg/100 fresh weight. Data are means derived from literature sources. The normal range of values is the mean at least 85%, and depends upon variety, agronomic conditions, tissue sampled and maturity... 

Table 7.1 shows the common dietary sources of carotenoids in regular vegetable foods, p,g/100 fresh weight. Although the greatest amount of the hydrocarbon carotenoids is present as the all-trans isomer, there is always a proportion of cis isomers present. This table represents only a small number of the fruits and vegetables that contribute carotenoids in the European diet. For more comprehensive information readers are directed to A European Carotenoid Database O Neill et al, 2001, which lists the carotenoid composition of over 100 food items. 

The carotenoids are the most widespread group of pigments in nature, with an estimated yield of 100 million tonnes per annum. They are present in all photosynthetic organisms and responsible for most of the yellow to red colours of fruits and flowers. The characteristic colours of many birds, insects and marine invertebrates are also due to the presence of carotenoids, which have originated in the diet. Animals are unable to synthesise carotenoids de novo, and so rely upon the diet as the source of these compounds. Carotenoids found in the human diet are primarily derived from crop plants, where the carotenoids are located in roots, leaves, shoots, seeds, fruit and flowers. To a lesser extent, carotenoids are also ingested from eggs, poultry and fish. Commercially, carotenoids are used as food colourants and in nutritional supplements (Table 13.1). Over recent years there has been considerable... 

New research has demonstrated that carotenoids may also lend additional health benefits that may possibly reduce the risk of certain types of chronic diseases such as cancer and heart disease. Carotenoids are also important natural sources of orange, yellow, and red food coloring for the food and beverage industries. ... 

Most of this amount is in the form of fucoxanthin in various algae and in the three main carotenoids of green leaves lutein, violaxanthin, and neoxanthin. Others produced in much smaller amounts but found widely are p-carotene and zeaxanthin. The other pigments found in certain plants are lycopene and capsanthin (Figure 2.2.1). Colorant preparations have been made from all of these compounds and obviously the composition of a colorant extract reflects the profile of the starting material. Carotenoids are probably the best known of the food colorants derived from natural sources. ... 

Sources Adapted from Rodriguez-Amaya, D.B., Carotenoids and Food Preparation, USAID/OMNl, Washington, DC, 1997 Takyi, E.E.K., Bioavailability of Carotenoids from Vegetables, CRC Press, Boca Raton,... 

Sources Britton, G., in Carotenoids IB Spectroscopy, Birkhauser Verlag, Basel,... 

Lycopene is a bright red pigment that colors several ripe fruits, vegetables, and flowers. Tomato and tomato products are the main dietary sources of this carotenoid, although it is also found in watermelons, guavas, pink grapefruits, and in small quantities in at least 40 plants. - The absorption of lycopene in the human gut is increased by heat treatment, probably because the breakdown of the plant cells makes the pigment more accessible. ... 

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