Natural oils

Natural oils

Triglycerides
Natural oils from vegetable sources are mainly glycerol esters based on mixtures of C_8/22 fatty acids. The most important are the saturated lauric (C12), myristic (C14), palmitic (C16), and stearic (C18) acids and the unsaturated oleic (C18) and linoleic (C18) acids. These fatty acids are derived from natural sources and typically have even numbers of carbon atoms in their chains.
Important characteristic values for triglycerides are the saponification number and the iodine number. The latter indicates the amount of unsaturated fatty acids present. Although, due to the natural source, better skin compatibility compared with synthetic materials is expected, triglycerides are relatively problematic to use in cosmetic emulsions. In addition to the difficulty of emulsification, the products can become rancid due tó the presence of unsaturated fatty acids. Consequently,antioxidizing agents usually have to be added.
It is important to use only high-quality triglycerides. Polycyclic aromatic hydrocarbons (PAHs) can be a problem, particularly in the case of coconut oil. This is due to contamination from blue gases when the copra, from which the coconut oil is derived, is dried. Treatment with activated carbon can remove these impurities.
Triglycerides are relatively fatty and spread very little on the skin. They generally show moderate comedogenicity, exceptions being sunflower oil and ...