| abstract |
A method of pigmenting the egg yolk, integuments and/or subcutaneous fat of poultry and the meat and/or integuments of fish and crustacea involves including in the feed of the poultry, fish or crustacea one or more of the carotenoids 2'-dehydroplectaniaxanthin, 1-hydroxy-3,4-didehydro-1,2-dihydro-Ψ,Ψ-caroten-2-one, desmethylspheroidenone, spheroidenone, 5'-hydroxy-5',6'-dihydro-4'-apo-β-caroten-6'-one, 1'-hydroxy-3',4'-didehydro-1',2'-dihydro-β,Ψ-carotene-4,2'-dione and 5'-hydroxy-5',6'-dihydro-4'-apo-β-carotene-4,6'-dione. Also embraced by the invention are the pertinent carotenoid-enriched feed for poultry, fish or crustacea, the premixes for incorporation in such feeds and beadlets containing one or more of these carotenoids for incorporation in such premixes, the use of the carotenoids in the pigmenting method and the four new carotenoids of the seven aforementioned carotenoids. The new carotenoids can be produced by condensing in each case an appropriate aldehyde with 3-hydroxy-3-methyl-2-butanone, thereby forming the characteristic terminal 2-hydroxy-2-methyl-propionyl group. |