Pigments riboflavin

Stable dispersion of water-insoluble and/or hydrophobic natural pigment such as carotenoid, curcumin, porphyrin pigment, or vegetable carbon black in form of bodies of average size of 10 ram Addition of 0.5 ppm P-carotene to yogurt containing 200 ppm riboflavin color did not change after 40 days at 6°C compared with control (decoloration at 1 day)... 

As aromatic compounds have been exhausted as building blocks for life science products, A-heterocyclic structures prevail nowadays. They are found in many natural products, such as chlorophyll hemoglobin and the vitamins biotin (H), folic acid, niacin (PP), pyridoxine HCl (Be), riboflavine (B2), and thiamine (Bi). In life sciences 9 of the top 10 proprietary drugs and 5 of the top 10 agrochemicals contain A-heterocycIic moieties (see Tables 11.4 and 11.7). Even modern pigments, such as diphenylpyrazolopyrazoles, quinacri-dones, and engineering plastics, such as polybenzimidazoles, polyimides, and triazine resins, exhibit an A-heterocydic structure. 

Juices extracts (liquorize), spirits (orange, lemon), syrups (black currant), tinctures (ginger), and aromatic waters Mineral pigments (iron oxides), natural colorants, anthocyanins, carotenoids, chlorophylls riboflavine, red beetroot extract, and caramel synthetic organic dyes azo compounds... 

More than one century ago a yellow, fluorescent pigment was isolated from whey by Blyth In the subsequent years yellow pigments were extracted from various biological materials. Depending either on the source of isolation or the physical appearance, these natural products were named e.g. lactochrome , lycochrome , ovoflavin , lactoflavin , hepatoflavin , or verdoflavin . Later, it became evident that all these compounds are riboflavin (vitamin B2). 

VITAMIN B2 (Riboflavin). Some earlier designations for this substance included vitamin G, lactoflavin, hepatoflavin, ovoflavin, veidoflavin. The chemical name is 6,7-dimcthyl-9-d-l ribityl isolloxazine. Riboflavin is a complex pigment with a green fluorescence. Riboflavin deficiency frequently accompanies pellagra and the typical lesions of both nicotinic acid and riboflavin deficiency are found in that disease. See also Niacin. 

One major reason for nutrient loss and off-flavor development today is due to extended exposure to fluorescent light in food retail display cases. Many foods and beverages are susceptible to light-induced reactions, especially those with photo-sensitizers. Natural pigments found in foods that commonly act as photochemical initiators are flavonoids, riboflavin (vitamin B2), chlorophyll, heme, and vitamin K. 

Several pigments, vitamins and coenzymes like carotenoids, riboflavin (B2), cobal-amine (B12), ascorbic acid (Q, ergosterol (D2), biotin (H), gibberellin, etc. are produced during the normal metabolism of microorganisms. Microbial production of some of... 

Riboflavin has a central role as a redox coenzyme in energy-yielding metabolism and a more recently discovered role as the prosthetic group of the cryptochromes in the eye - the blue-sensitive pigments that are responsible for day-length sensitivity and the setting of circadian rhythms. 

Although crystalline riboflavin was not isolated until 1931 interest in this compound as a pigment dates back to 1881 in connection with the color in the whey of milk. In 19.31 riboflavin was isolated as a coenzyme-en/.yme complex from yeast by Warburg and Christian and was designated yeiioiv oxidation ferment. 

CAS 83-88-5. C17H20N4O6. A crystalline pigment, the principal growth-promoting factor of the vitamin B2 complex. It functions as a flavoprotein in tissue respiration. A syndrome resembling pellagra is thought to be due to riboflavin deficiency. 

SOME OTHER NATURAL PIGMENTS 9.8.1 Riboflavin and riboflavin 5 phosphate... 

Riboflavin, vitamin B2 (Formula 9.17), is a yellow pigment present in many products of plant and animal origin. Milk and yeast are the best sources of riboflavin. 

Most vitamins function either as a hormone/ chemical messenger (cholecalciferol), structural component in some metabolic process (pantothenic acid), or a coenzyme (phytonadi-one, thiamine, riboflavin, niacin, pyridoxine, biotin, folic acid, cyanocobalamin). At least one vitamin has more than one biochemical role. Vitamin A as an aldehyde (retinal) is a structural component of the visual pigment rhodopsin and, in its acid form (retinoic acid), is a regulator of cell differentiation. The precise biochemical functions of ascorbic acid and a-tocopherol still are not well defined. 

Besides its function as a precursor of FAD and FMN riboflavin is a pigment. In A. gossypii riboflavin was shown to protect the hyaline ascospores against UV-light. In photoreceptors of migratory birds FAD works as... 

Apart from the derivatives of p-carotene, other pigments are the anthocyanins, the chlorophylls, cochineal, the betalaines, turmeric, caramel and riboflavin. In this account the historical background in brief, the chemistry of these pigments, their extraction from natural sources and their synthesis will be discussed. The present permitted natural substances and nature-identical synthetic materials (also described by the Food and Drugs Administration, the FDA, as colorants exempt from certification ) is quite small in number. Reference is also made to colourants no longer listed but which have an historical organic chemical significance such as for example brazilin and its relative haematoxylin. 

Riboflavin (2) and some related flavins are pigments of potential importance for aquatic photochemistry that exist at low concentrations in natural waters. These compounds have broad, moderately strong absorption bands in the visible region at about 440 nm and show high quantum yields for triplet formation (Heelis, 1982). 

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