A novel process for the manufacture of .beta.-keto alcohols from aldehydes comprising reacting a conjugated polyene aldehyde under basic conditions with a cyclocarbonate or derivative thereof. Certain carotenoid products of this process are novel compounds and are also an object of the present invention. The products, which for the most part belong to the carotenoid field, find corresponding use, for example, as colorants or pigments for foodstuffs, egg yolk, integuments and/or subcutaneous fat of poultry and flesh and/or integuments of fish and crustaceans.
New carotenoids of the formula ##STR1## wherein R and n have the significances given herein, are useful for pigmenting the egg yolk, integuments and/or subcutaneous fat of poultry and the meat and/or integuments of fish and crustacea when included in the feed of the poultry, fish or crustacea. As well as such carotenoids and method of pigmenting the invention further embraces 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 and the use of the carotenoids in the pigmenting method. The process of manufacturing such carotenoids, which more specifically may be designated as carotenoid ketones, monoesters and diesters, also represents an aspect of the invention.
