If you have a spare 15 minutes, I highly recommend listening to part of this "Fake Food" podcast from Christopher Kimball's Milk Street Radio. The relevant section starts at about 18:30. Here are a few high(low?)lights:
- More money is made in food fraud worldwide than in narcotics trafficking.
- In light of the above, it's not surprising that food adulteration is big organized crime business, all over the world.
- Daffodil extract has been added to sunflower oil to make it look like olive oil.
- Parmesan cheese has been adulterated with shredded cardboard.
- When demand for a product of limited availability surges, fraud follows. (When coconut products became popular, what sold as "coconut water" was often just water, sweetened. You can't get more coconut palms fast enough to meet the increased demand.)
- 25% of the oregano sold has been adulterated. In Australia, that's 70%. (That really makes me appreciate the live oregano growing in our front garden.)
- Often even if the adulterants are theoretically not harmful, e.g. shredded olive leaves in oregano, they can be dangerous—olive leaves are often drenched in pesticides.
You get the depressing picture. The good news? Food scientists are getting better at detecting adulterated products, and someday soon your phone may have an app for that.