[Canada] Olive oil circuit runs nano-scale rings round silicon
Once, researchers grew a light-sensitive semiconductor in a flask of ultra-pure oleic acid — the main ingredient of olive oil — and painted it onto glass. It sounds like alchemy, but it points to a real truth: olive oil’s defining molecule is unusually useful.
Every so often olive oil turns up somewhere unexpected — not on a plate but in a laboratory, as the raw material for something high-tech. In one striking case, scientists made light-sensing nanocrystals in a flask of ultra-pure oleic acid, the principal component of olive oil, then spread them into a thin film on glass to build a detector more sensitive to infrared than the sensors then used in night vision. You do not need the physics to take the point: the molecule that makes olive oil what it is happens to be a genuinely versatile substance.
Meet oleic acid
Oleic acid is the fatty acid that dominates olive oil — depending on the variety and region, very roughly half to over four-fifths of the oil is this single compound. It is a monounsaturated fat, meaning its carbon chain has exactly one double bond, and it belongs to the omega-9 family. That structure is not a trivia point; it is the reason olive oil behaves the way it does, in the pan and in the body. The name even nods to its source: oleic, from oleum, oil — the olive gave the acid its name, not the other way round.
Why that one double bond matters
Fats with many double bonds — the polyunsaturated oils — are chemically busy and prone to oxidation, which is why they can turn rancid and degrade under heat. Saturated fats, with none, are stable but solid and less kind to the arteries. Oleic acid sits in the sweet spot: one double bond gives it good stability while keeping it liquid and heart-friendly. That single structural fact explains why olive oil resists heat better than most seed oils and why it keeps reasonably well — the chemistry the nanocrystal experiment exploited is the same chemistry that makes it a good cooking oil.
The same molecule, many jobs
Because it is stable, abundant and non-toxic, oleic acid earns its keep far beyond the kitchen — in soaps and cosmetics, as a carrier and emulsifier, in industrial chemistry, and, in that memorable experiment, as the medium for growing delicate nanocrystals. None of this makes your bottle more nutritious; it simply shows that the thing you drizzle on a salad is, at heart, an elegant and useful molecule. The oil on your bread and the acid in that flask are, chemically, close cousins — a nice reminder that olive oil is chemistry you can eat.
| Molecule | Oleic acid (cis-9-octadecenoic acid) |
|---|---|
| Type | Monounsaturated fatty acid (omega-9) |
| Double bonds | One |
| Share of olive oil | Roughly 55–83%, varying by variety |
| Kitchen consequence | Heat stability and reasonable shelf life |
| Other uses | Soaps, cosmetics, emulsifiers, lab chemistry |
- Olive oil is mostly one fatty acid, oleic acid — a monounsaturated omega-9 fat.
- Its single double bond is why olive oil is stable to heat yet stays liquid and heart-friendly.
- Oleic content varies by variety, which is part of why oils differ in character and keeping.
- The same molecule is useful well beyond food — a sign of how versatile it is.
Oleic acid and olive oil: common questions
What is oleic acid?
It is the main fatty acid in olive oil — a monounsaturated fat of the omega-9 family, with a single double bond in its carbon chain.
How much of olive oil is oleic acid?
Very roughly between about 55% and over 80%, depending on the olive variety and where it was grown.
Why is oleic acid good for cooking?
Its single double bond makes it more stable to heat and oxidation than polyunsaturated oils, while staying liquid and considered heart-friendly.
Is oleic acid used outside food?
Yes — in soaps, cosmetics, emulsifiers and industrial and laboratory chemistry, thanks to its stability and abundance.
Does higher oleic acid mean better oil?
It contributes to stability and shelf life, but flavour, freshness and how the oil was made matter just as much to overall quality.
You do not need to care about semiconductors to take something from this. The lesson is that olive oil is not a vague health potion — it is mostly one well-understood molecule, oleic acid, and that molecule’s tidy structure explains the practical things you actually notice : why the oil handles heat, why it keeps, why it pours the way it does. When a variety is described as high in oleic, that is shorthand for a more stable, longer-keeping oil — useful to know when you are choosing a bottle to keep in the cupboard.
Drawn from the basic chemistry of oleic acid and olive-oil fatty-acid composition; percentage range given broadly.