Specifically with truffle oil - its taste profile is so noticeable different, that unless you never had a real truffle, it would be easy to spot. As for differ

Specifically with truffle oil - its taste profile is so noticeable different, that unless you never had a real truffle, it would be easy to spot. As for different things, about 7 years ago in LA there was as huge wine counterfeit operation bust. Expensive bottles were filled with cheaper wine, re-corked and sold. This is why expensive bottles now "destroyed" one way or another. Point is - easier to sell and fewer troubles.