oleoresins

An oleoresin is a natural extract derived from plants that combines a resinous, non-volatile solid or semisolid fraction with a substantial amount of volatile essential oil. This composition gives oleoresins the characteristic aroma, color, and viscosity of their plant source. Oleoresins differ from pure essential oils, which are mostly volatile, and from crude resins, which lack the distinct essential-oil fraction.

Oleoresins are produced from a wide range of plants, including conifers such as pine (turpentine–type oleoresins) and spices such as paprika, capsicum, and black pepper. In the spice industry, oleoresins are prepared by solvent extraction of the dried plant material; the solvent is removed to yield a viscous, resin-rich concentrate that preserves both aroma compounds and pigments.

Chemically, oleoresins contain resinous acids and terpenoid constituents derived from the plant's resin and essential oil. They are typically soluble in nonpolar organic solvents (for example hexane, benzene, or chloroform) and are not water-soluble. Their physical form ranges from viscous liquids to solid masses, depending on composition and temperature.

Applications include flavoring and coloring agents in foods (paprika and chili pepper oleoresins are common examples) and components in perfumery and cosmetics. They are also used in some varnishes and coatings as resinous additives that impart gloss and hardness.

Storage and handling require cool, dry, out-of-sun conditions to minimize volatilization and color or flavor loss. Safety considerations include standard handling precautions for plant resins and essential oils, with attention to potential allergenicity in sensitive individuals.