Xanthophyll

Xanthophylls ( AltGr. Ξανθός Xanthos "yellow" and φύλλον phyllon "leaf" ) are in addition to the carotenes, the second major group of carotenoids. The xanthophylls are - like the carotenes also - mostly tetraterpenes but contain oxygen-containing groups in the form of hydroxyl (-OH), carbonyl (-C = O) and carboxyl (-COOH ) and rarely also of oxirane groups.

Occurrence

Xanthophylls are found in the plastids of all photosynthetic cells of plants. In the domain of eukaryotes they can be synthesized only by plants; representatives found in animals are then fed through the food. Xanthophylls are also green colored leafy vegetables such as spinach (10 mg/100 g ), salad, and included in kale (20 mg/100 g). In the domain of prokaryotes, they are formed by some bacteria that live in locations that are exposed to light strongly. The pigments in the cell membrane to protect them from the photo-oxidation of cell components.

Properties

The xanthophylls are lipophilic in spite of the polar groups and thus often not very soluble; part, the solubility in water is improved through glycosylation with a monosaccharide. Xanthophylls are sensitive to heat and are destroyed during cooking at 60-100 %. They occur both in animals and in plants as dyes. Most xanthophylls have a yellow, red or orange coloration are rarer blue or violet shades.

Important representatives

  • Astaxanthin ( red-violet ), main carotenoid of marine fauna ( eg salmon, lobster )
  • Canthaxanthin ( red) dye in crab, flamingo feathers and chanterelles
  • Capsanthin (red), the pigment of the red pepper fruits
  • Fucoxanthin (brown), the pigment of brown algae ( Phaeophyceae )
  • Lutein ( yellow-orange ), a dye that is present in the chloroplast
  • Myxoxanthophyll (purple ), a dye of cyanobacteria
  • Sarcinaxanthin (yellow), a dye (for example, Micrococcus luteus ) occurs in certain bacterial species
  • Violaxanthin (yellow), a sheet of dye
  • Zeaxanthin (orange yellow), the most important protection of the photosynthetic apparatus pigment ( xanthophyll )

Use

Xanthophylls are added to dyeing in animal products to obtain feed. For example, astaxanthin is added to the characteristic color of meat to get the fish meal for farmed salmon or admixed to chicken feed to intensify the color of the yolk. Canthaxanthin is directly used for re-dyeing of pollock. Lutein is used as a dye in non-carbonated beverages like, energy bars and dietary food use.

Paprika oleoresin Photo-oxidation of polymers Orange (colour) Xanthophyll#Xanthophyll cycle Digital Object Identifier
251015
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