Oleoresin is a semi-solid extract composed of resin and essential or fatty oil, obtained by evaporation of the solvents used for their production. It is a naturally occurring combination of oil and resin that can be extracted from plants. Oleoresins are similar to perfumery concretes, obtained especially from flowers, and to perfumery resinoids, which are prepared also from animal secretions. The extraction process begins by using a suitable organic solvent such as acetone, ethanol, ethyl acetate, or ethylene dichloride. The solvents used are nonaqueous and may be polar (alcohols) or nonpolar (hydrocarbons, carbon dioxide) . Oleoresins are prepared from spices such as basil, 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, and West Indian bay leaves.

Oleoresins are highly concentrated substances that exist in liquid form. They are easy to store and transport because concentrated forms reduce space and bulk. They can be more heat stable than raw spices and have a longer shelf life due to lower moisture content. Oleoresins contain essential oil, non-volatiles, fixed oil, pigments, and natural antioxidants. Oleoresins are added into almost every food application to contribute the attributes of the natural spice such as flavor, color, or as a natural antioxidant. Because oleoresins are highly concentrated, they are usually diluted before use in a final application.