What molecules make up hazelnut oil?

Like most vegetable oils, hazelnut oil is primarily composed of fatty acids. In its composition, three are found in significant proportions.

• The monounsaturated fatty acids such asoleic acid (also known asomega 9), present in a mass fraction ranging from 71 to 87%. Although synthesised by the body, external supply (topically) of omega 9 is necessary to strengthen the skin's protective barrier. Indeed, these fatty acids constitute the hydrolipidic film, the layer that protects the skin from aggressions and maintains its hydration level. These are lipids that are part of the composition of sebum, a substance naturally secreted by the body to counteract the dryness of the skin and hair. Oleic acid is therefore recognised by the skin's constituents, and thus penetrates deeply to regulate sebum production by the sebaceous glands and combat the oily tendency of the hair and skin.

• The polyunsaturated fatty acids, including thelinoleic acid or omega 6, present in a mass fraction ranging between 7 and 18%. This category of fatty acids is referred to as essential, as they are not synthesised by the body. Omega 6 contributes to the process of cellular renewal. When applied topically, they therefore help to combat signs of ageing and promote healing. They also soothe inflammatory reactions and are beneficial for sensitive skin, suffering from tightness and irritation.

• Saturated fatty acids, such as thepalmitic acid, constitute 4 to 8% of the total composition of hazelnut oil. Palmitic acid has emollient properties, which means it promotes the hydration of skin and hair cells. It thus provides suppleness and softness.

As the name suggests, the "unsaponifiable" fraction of a vegetable oil represents the elementsthat are not transformed into soap during a saponification reaction. These include sterols, hydrocarbons (squalene, etc...), fatty alcohols (waxes, etc...), liposoluble pigments, vitamins, polyphenols, minerals, etc... Generally, this unsaponifiable fraction only accounts for 0.5 to 2% of vegetable oils.

Hazelnut oil contains 0.3% to 0.7% unsaponifiable matter, primarily composed of vitamin E and phytosterols, potentnatural antioxidants.They protect the skin and hair from the damaging effects of free radicals, which arereactive oxygen speciesproduced naturally by the body but overproduced when cells are exposed tostress. Stress sources are numerous, the main ones being UV exposure, pollution, smoking, and a diet too rich in fats and/or sugars. Free radicals are particularly unstable molecules due to theirsingle electron. They tend to react with other molecules to form anelectron pair, thereby causingdamage to the body's cells, DNA, and proteins. They are notably involved in lipid peroxidation, a degradation reaction of the constituents of cell membranes. This accelerates ageing and causes wrinkles to appear on the skin's surface. Regarding hair, free radicals weaken hair fibres, hastening their fall and/or the appearance of white hair. Therefore, hazelnut oil is a valuable ally in preventing skin ageing, combating the onset and/or accentuation of wrinkles, as well as the degradation of hair strength over time.