Omega-9 fatty acid in the context of "Essential fatty acid"

Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish due to the presence of impurities. In chemical terms, oleic acid is classified as a monounsaturated omega-9 fatty acid, abbreviated with a lipid number of 18:1 cis-9, and a main product of Δ9-desaturase. It has the formula CH₃−(CH₂)₇−CH=CH−(CH₂)₇−COOH. The name derives from the Latin word oleum, which means oil. It is the most common fatty acid in nature. The salts and esters of oleic acid are called oleates. It is a common component of oils, and thus occurs in many types of food, as well as in soap.

Ostrich oil is an oil derived from the fat of ostriches. Ostrich oil is composed of 36.51% of saturated fat, 46.75% of monounsaturated fat, and 18.24% of polyunsaturated fat. Ostrich oil contains fatty acids, such as omega-3, omega-6, and omega-9. It also contains vitamins and minerals like vitamin E and selenium, which serve as natural antioxidants. Emu oil in the USA has a similar composition to ostrich oil, but ostrich oil has a higher omega-3 content, containing 2.1% compared to 0.25% in emu oil.

Ostrich oil has antibacterial properties, and is used for various skincare purposes, such as inflammation reduction. Due to the moisturizing properties, ostrich oil is currently used in cosmetic formulations and food chemistry. Ostrich oil is also used in the food industry as it has fatty acids and tocopherols, and a low cholesterol content.

Erucic acid is a monounsaturated omega-9 fatty acid, denoted 22:1ω9. It has the chemical formula: CH₃(CH₂)₇CH=CH(CH₂)₁₁CO₂H. It is prevalent in wallflower seed and other plants in the family Brassicaceae, with a reported content of 20 to 54% in high erucic acid rapeseed oil and 42% in mustard oil. Erucic acid is also known as cis-13-docosenoic acid and the trans isomer is known as brassidic acid. Cetoleic acid is a positional isomer of erucic acid.

Emu oil is an oil derived from body fat harvested from certain subspecies of the emu, Dromaius novaehollandiae, a flightless bird indigenous to Australia.

Unadulterated emu oil can vary widely in colour and viscosity anywhere from an off-white creamy texture to a thin yellow liquid, depending on the diet of the emu and the refining method(s) used. Industrially refined emu oil is composed of a minimum of 70% unsaturated fatty acids. The largest component is oleic acid, a monounsaturated omega-9 fatty acid. Emu oil also contains roughly 20% linoleic acid (an omega-6 fatty acid) and 1–2% linolenic acid (an omega-3 fatty acid). Fully refined emu oil has a bland flavour.

Ricinoleic acid, formally called 12-hydroxy-9-cis-octadecenoic acid, is a fatty acid. It is an unsaturated omega-9 fatty acid and a hydroxy acid. It is a major component of the seed oil obtained from the seeds of castor plant (Ricinus communis L., Euphorbiaceae), the plant that produces ricin. It is also found in the sclerotium of ergot (Claviceps purpurea Tul., Clavicipitaceae). About 90% of the fatty acid content in castor oil is the ricinolein.