Betalains and

FIGURE 2.4.1 Biosynthetic routes leading to betalains and anthocyanins. ... 

Vareltzis, K.R and Buck, E.M., Color stability and sensory attributes of chicken frankfurters made with betalains and potassium sorbate versus sodium nitrite, J. Food Protect., 47, 41, 1984. 

Adachi, T. and Nakatsukasa, M., High-performance liquid chromatographic separation of betalains and their distrihution in Portulaca grandiflora and related species, Ztschr. Pflanzenphysiol., 109, 155, 1983. 

Kujala, T., Loponen, J., and Pihlaja, K., Betalains and phenolics in red beetroot Beta vulgaris) peel extracts extraction and characterisation. Ztschr. Naturforsch. C/J. Biosci., 56, 343, 2001. 

Zakharova, N.S. and Petrova, T.A., Investigation of betalains and betalain oxidase of leaf beet, Appl. Biochem. Microbiol., 33, 539, 1997. 

Kujala, T.S. et al., Betalain and phenolic compositions of four beetroot Beta vulgaris) cultivars. Fur. Food Res. TechnoL, 214, 505, 2002. 

FIGURE 13.1 Typical structures for main pigment classes zeaxanthin (carotenoid), chlorophyll a (chlorophyll), quercetin (flavonoid), cyanidin (anthocyanidin), betanin (betalain), and alizarin (anthraquinone). 

Scheme 10. Possible biosynthetic routes leading from the shikimic acid pathway to betalains and the coexisting flavonoids (excluding anthocyanins) in betalain-bearing members of the Caryophyl-lales.

A. belongs to the group of betacyanins (see betalains) and occurs especially in Amaranthus (Amaranthaceae) and Chenopodium species (Chenopodiaceae). 

Boot roots, red beets. The cultured form of Beta vulgaris (Chenopodiaceae) has been used in Europe as a biennial vegetable plant since the 13th century. They are rich in oxalic acid (>300 mg/kg, in leaves >900 mg/kg), nitrate (200 mg/kg), and sodium (>80 mg/kg). The dark red color is due to the content of betanin (see betanidin) and other betalains and the typical odor to geosmin. The pressed juice is permitted for use as a food colorant. 

It has also been suggested that the betalain- and anthocya-nin-producing families of this order developed from a common ancestor before the widespread occurrence of floral pigments in angiosperms (Mabry, 1976). All families of the Caryophyllales contain sieve-tube cells with proteinaceous inclusions which are not encountered in other plant families. However, because anthocyanins are known from most other groups of plants including gymnosperms and ferns, it seems likely that the ancestors of the Caryophyllales also possessed anthocyanins. 

Various natural pigment classes, such as flavonoids, antho-cyanins, carotenoids, chlorophylls and chlorophyll derivatives, porphyrins, quinones, anthraquinones, betalains, and so forth are abundant in many families of the vegetable and animal kingdoms. As consumers generally dislike the color of synthetic dyes, the concentration and composition of pigments in foods and food products exert a considerable impact on the consumer acceptance and, consequently, on the commercial value of the products. It has been proven many times that one of the main properties employed for the commercial evaluation of the quality of products is their color that is, an adequate color is an important requirement of marketability. 

Examples of tetrapyrroles include porphyrins and porphyrin derivatives and more specifically, chlorophylls, heme pigments and bilins. Examples of tetra-terpenoids or carotenoids include carotenes and xanthophylls. Examples of quinines include benzo-quinones, anthraquinones and naphthiquinones. Examples of oxygen-containing heterocyclic compounds such as flavonoids include anthocyanins and flavonols. Examples of nitrogen-containing heterocyclic compounds include indigoids and indole derivatives, such as betalaines and eumelanins, and substituted pyrimidines such as pterins and purines. 

Besides the more restricted occurrences of the red carotenoids and the red to purple betalains and anthraquinones, anthocyanins are largely responsible for the scarlet through purple to blue colors of flowers, fruits, roots and leaves of higher plants, fruit juices, red wines, etc. They are accumulating in the vacuoles of epidermal or subepidermal cells, but may also be confined to the leaf mesophyll. Around 300 different naturally occurring anthocyanins have been reported (27). 

Betalains and betanin have shown potent in vitro antioxidant activity. Betanin inhibited lipid perioxidation in vitro more potently than catechin " and in humans showed have high bioavailability. 

Approximately 1500 colored compounds, also known as natural food pigments, have been isolated from foodstuffs. On the basis of their chemical structure, these food pigments can be grouped in the following six classes heme pigments, chlorophylls, carotenoids, flavonoids, betalains, and miscellaneous pigments. 

B. Nemzer, Z. Pietrzkowski, A. Sp6ma, P. Stalica, W. Thresher, T. Michalowski, S. Wybraniec, Betalainic and nutritional profiles of pigment-enriched red beet root (Beta vulgaris L.) dried extracts. Food Chem., 127(2011)42-53. 

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