Oleoresins are semi-solidextracts composed ofresin andessential orfatty oil, obtained by evaporation of the solvents used for their production.^[1] The oleoresin ofconifers is known ascrude turpentine orgum turpentine, which consists ofoil of turpentine androsin.^[2]

In contrast toessential oils obtained bysteam distillation, oleoresins abound in heavier, less volatile and lipophilic compounds, such asresins,waxes,fats andfatty oils. Gummo-oleoresins (oleo-gum resins, gum resins) occur mostly as crudebalsams and contain also water-solublegums. Processing of oleoresins is conducted on a large scale, especially in China (400,000 tons per year in the 1990s), but the technology is too labor-intensive to be viable in countries with high labor costs, such as the US.^[3]

Oleoresins are prepared from spices, such asbasil,capsicum (paprika),cardamom,celery seed,cinnamon bark,clove bud,fenugreek,fir balsam,ginger,jambu,labdanum,mace,marjoram,nutmeg,parsley, pepper (black/white), pimenta (allspice),rosemary,sage,savory (summer/winter),thyme,turmeric,vanilla, andWest Indian bay leaves. The solvents used are nonaqueous and may be polar (alcohols) or nonpolar (hydrocarbons, carbon dioxide).^[4]

Oleoresins are similar to perfumeryconcretes, obtained especially from flowers, and to perfumeryresinoids, which are prepared also from animal secretions.

Most oleoresins are used as flavors and perfumes, some are used medicinally (e. g.,oleoresin of Cannabis).Oleoresin capsicum is commonly used as a basis for pepper sprays. There are also uses known in the manufacture of soaps of cosmetics, as well as coloring agents for foods. A well-known pipe thread sealant, Rectorseal #5, is stated to have an "oleoresinous base".