It's slightly, but only a little. When you buy truffles you should preserve them in oil actually (because it won't take out the flavour), it will be scented but barely so. And the truffle will last more

Surely it doesn't need to be a solution - it can just be a suspension? The difference between extra virgin olive oil and purer grades are that the purer grades are filtered, not (e.g.) distilled.

Extra means the oil contains no more than 0.8% of free oleic acid.

Virgin means the oil comes from a mechanical process, not a chemical one.

The purest grade extra virgin olive oil is the first cold pressed. It's neither filtered nor distilled. Refined olive oil however is filtered and also tasteless.

https://en.wikipedia.org/wiki/Olive_oil#Commercial_grades

From the same page: "The refining process removes colour, odour and flavour from the olive oil, and leaves behind a very pure form of olive oil that is tasteless, colourless and odourless and extremely low in free fatty acids"

I don't mean 'pure' in a good sense, just that it is a simple mixture.