Could have the color change by percentage but I'd be fine if it just said if there was ANY seed oil.
-- doctorremulac3, Feb 18 2025

Apparently it's possible to detect down to 1% adulteration with vegetable oil using mass spec. And HPLC presumably works, although slower. But these are a long way away from a 'test strip'.
I'm not sure a pH-paper -like strip is possible. Maybe with a lot of development something like a covid self-test kit could be made. But even that doesn't seem particularly feasible.

You'd be looking for either marker compounds which aren't present in olive oil, or a different composition of fatty acids.
The former is perhaps possible in a small kit - but only if a) you know what the adulterating oil might be, and b) such a marker exists. For the latter... well, I think the reason they're using mass spec and HPLC is, that's basically what they're doing, and that is a bit more complicated than a single, simple quantitive reaction.

The wikipedia olive oil page has large sections on "Regulation" and "Mislabeling and adulteration", and a handy table comparing olive oil to other vegetable oils.

The main ingredients of olive oil are:
Oleic acid, 55 to 83%
Linoleic acid, 3.5 to 21%
Palmitic acid, 7.5 to 20%

So I suppose what you could do is detect those chemically (somehow! A whole titration for each one!) and look for deviations outside that range. That won't pick up e.g. high-oleic safflower or avocado oils, which has a similar profile. Maybe that doesn't matter, if they're equally as good for you. And I suspect they're not the common adulterants - they're probably as expensive anyway.
-- Loris, Feb 18 2025


However it's done, seems like there's a market for it as people are learning how important good fats are in your diet. (Along with the revelation that there are good fats and bad fats)
-- doctorremulac3, Feb 18 2025


//However it's done,//

Probably several hours work to do it with individual chemical tests, including setup and clean-up. Plus you'll need a good bench surface and some rather expensive glassware. Also, there will be some calculations involved.
Hearing that, I suspect most people will become less interested in doing it themselves, and maybe consider the benefits of sending off a sample to a lab.
-- Loris, Feb 18 2025


I heard that one trick you can use is how direct the shipment was. If it has more than one stopover processing point there's a good chance it's been cut.

In Italy supposedly this is a big mafia thing. Can you imagine trying to impress somebody with your mob credentials with this?
-- doctorremulac3, Feb 18 2025



random, halfbakery