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Carotenoids

Carotenoids. Jaromír Kupka, Vladimír Ondruška. Introduction. Nature ’s widespread pigments biosynthese by ocean algae masked by dominant chlorophyll fotosynthesis and photoprotection ability inactivate reactive oxygen precursors of vitamin A. Introduction.

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Carotenoids

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  1. Carotenoids • Jaromír Kupka, Vladimír Ondruška

  2. Introduction • Nature’s widespread pigments • biosynthese by ocean algae • masked by dominant chlorophyll • fotosynthesis and photoprotection • ability inactivate reactive oxygen • precursors of vitamin A

  3. Introduction • Provitamin A presents 30 -100 % of the vitamin A requirement • retinoid structure  vitamin A activity

  4. Hydrocarbons carotenes Oxygenated xanthophylls Structures of carotenoids I Two groups of structure

  5. Structures of carotenoids II • groups on xantophylls: • hydroxyl, epoxy, aldehyde and keto • isoprene unit = basic structure

  6. Some types ofcarotenoids

  7. Occurrence and distribution • Fruit and vegetables: • Tomatoes (lycopene) • Carrots (-, -carotenes) • Red peppers (capsanthin) • Pumpkins (-carotene) • Sweet potatoes (-carotene)

  8. Occurrence and distribution • All green vegetables contain carotenoids but their color is masked by the green chlorophylls

  9. Physical properties • All carotenoids are lipophilic compounds and thus are soluble in oils and organic solvents • they can be isomerized by heat, acid, light • many carotenoids exhibit spectral shifts with various reagents and these spectral changes are used for identification

  10. Chemical properties • Carotenoids are easily oxidized because of large number of conjugated double bonds • Such reactions cause color loss of carotenoids in foods • Destability of a particular pigment to oxidation is highly dependent on its environment

  11. Vocabulary • Algae - řasy • dependent - závislý • storage - skladování • spectral shift - • spekt. přechod • susceptibility - citlivost

  12. Thank you for your attention

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