Fatty Acid Profile

Every plant oil is a mixture, and the mixture is what a fatty acid profile describes: how much of it is oleic, how much linoleic, how much of the saturated acids, and in a few oils how much of the more unsaturated ones. Two oils from unrelated plants with similar profiles behave more alike than two from related plants with different ones.

The profile predicts three things reasonably well. Feel and weight, since more saturation and longer chains make a heavier, more solid material. Keeping quality, since every double bond is a place oxidation can begin, so a more unsaturated oil has a shorter honest life. And how quickly an oil stops being noticeable, which is what most people mean by absorption.

What it does not settle matters as much. One acid quoted on its own is not a profile, and a profile is not a claim about what an oil does for skin. Batch moves it too: variety, soil, season and pressing all shift the numbers behind one unchanging name on an ingredient list.

The practical use is comparison. If an oil suited you, its profile is a better guide to the next one than the marketing is; if one did not, the profile is where to look for the reason. Suppliers publish typical ranges and brands rarely publish anything, so a figure you find is almost always a typical value, not a measurement of the bottle in your hand.