Abstract: The use of ?-zeacarotene, ?-zeacarotene or a mixture of both as a coloring agent for food or pharmaceutical compositions. For addition to the food or pharmaceutical composition or otherwise incorporation therein during its preparation the zeacarotene (mixture) is generally first formulated to a solid or liquid colorant composition in the form of a stable water-soluble or -dispersible powder, an aqueous colloidal solution or oil-in-water dispersion of such powder, an oil-in-water dispersion of the zeacarotene (mixture), or an oil-soluble dispersion of the zeacarotene (mixture) in a triglyceride. In a solid colorant composition the zeacarotene (mixture) is generally finely dispersed in a matrix or carrier.

Abstract: A process for the conversion of lutein or of its esters into zeaxanthin by base-catalyzed isomerization is disclosed. The process is carried out by heating an optionally pre-treated lutein-containing material in a mixture of an aqueous solution of an alkali hydroxide and either dimethyl sulphoxide or an organic solvent based on saturated aliphatic and/or aromatic hydrocarbons at temperatures in the range from about 50.degree. C. to about 120.degree. C. The process is carried out in the presence of a phase transfer catalyst when an organic solvent based on hydrocarbons is used. Being carotenoids, lutein and zeaxanthin are used correspondingly, especially as pigments for egg yolk, the integuments and the subcutaneous fat of poultry, the flesh and the integuments of fish and crustaceans, as well as foodstuffs. Zeaxanthin is preferably used in many applications, since in comparable dosages it produces a more intensive golden yellow pigmentation than lutein.

Abstract: A method of pigmenting certain parts and products of poultry, fish and crustacea by including in the feed of the pertinent animal one or more of the carotenoids 2'-dehydroplectaniaxanthin, desmethylspheroidenone, spheroidenone, 1-hydroxy-3,4-didehydro-1,2-dihydro-.psi.,.psi.-caroten-2-one, 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-caroten-6'-one, 1'-hydroxy-3',4'-didehydro-1',2'-dihydro-.beta.,.psi.-carotene-4,2'-dione and 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-carotene-4,6'-dione, poultry, fish and crustacea feeds for pigmenting certains parts and products of these animals, beadlets and premixes for adding to poultry, fish and crustacea feeds, and the carotenoids 1-hydroxy-3,4-didehydro-1,2-dihydro-.psi.,.psi.-caroten-2-one, 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-caroten-6'-one, 1'-hydroxy-3',4'-didehydro-1',2'-dihydro-.beta.,.psi.-carotene-4,2'-dione and 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-carotene-4,6'-dione.

Abstract: A method of pigmenting certain parts and products of poultry, fish and crustacea by including in the feed of the pertinent animal one or more of the carotenoids 2'-dehydroplectaniaxanthin, desmethylspheroidenone, spheroidenone, 1-hydroxy-3,4-didehydro-1,2-dihydro-.psi.,.psi.-caroten-2-one, 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-caroten-6'-one, 1'-hydroxy-3',4'-didehydro-1',2'-dihydro-.beta.,.psi.-carotene-4,2'-dione and 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-carotene-4,6'-dione, poultry, fish and crustacea feeds for pigmenting certains parts and products of these animals, beadlets and premixes for adding to poultry, fish and crustacea feeds, and the carotenoids 1-hydroxy-3,4-didehydro-1,2-dihydro-.psi.,.psi.-caroten-2-one, 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-caroten-6'-one, 1'-hydroxy-3',4'-didehydro-1',2'-dihydro-.beta.,.psi.-carotene-4,2'-dione and 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-carotene-4,6'-dione.

Abstract: A process for producing carotenoids and carotenoid intermediates via reduction of sulfonyl polyenes with a dithionite in the presence of ammonia or an aliphatic amine, including novel intermediates in this process, which carotenoids are known coloring agents for foodstuffs, animal feeds, pharmaceuticals, etc.

Abstract: A silyl-enol ether of the formula ##STR1## wherein n stands for the number and X stands for a group ##STR2## or n stands for the number 1 and X stands for the 6,11-dimethylhexadeca-2,4,6,8,10,12,14-heptaene-2,15-diyl group, the symbols R.sup.1 have the same or different significances and denote alkyl groups, and the symbol R.sup.2 represents a trialkylsiloxy group --OSi(R.sup.1).sub.3 or an ether group,is oxidized with percarboxylic acid and, if desired, the resulting .alpha.-siloxy ketone is hydrolyzed to an .alpha.-hydroxy ketone. This process is especially suitable for the manufacture of astaxanthin.

Abstract: A method and arrangement is provided for fastening and centering a tool comprising a die element and a punch element, in a press. A centering setup socket is axially displaceable on one tool element and has close fit on the other tool element. The setup socket remaining on said one tool element is retractable from the other tool element by the relative movement of the tool elements.