WHY ARE CHILI PEPPERS HOT?
See Also: Chili Peppers I; Chili Peppers II; Chili Pepper Trivia
We all know some chili peppers are hotter than others.
Why? Higher levels of capsaicin, the chemical that makes them hot.
But, the question is still basically the same - Why do some chilies have more capsaicin, which makes them hotter?
Studies in Bolivia, where it is believed chilies first evolved, show that in areas with the most fruit eating insects, the chili peppers are hotter.
Is it a self defense mechanism to discourage insects from eating them?
NO, the fruit eating insects and birds in the area are not affected by capsaicin. Both still nibble on the chili peppers.
OK, so why do some chilies have more capsaicin, making them hotter than others - there should be a reason. Why do chilies have ANY capsaicin at all? What is the advantage? Self defense would seem to be the logical reason.
A new study (Joshua Tewksbuty, Univ of Washington in Seattle) suggests the capsaicin IS for self defense. But not against insects or birds.
Capsaicin is a chemical defense against a fungus that feeds on chili pepper seeds. Where there are more insects that feed on chili peppers, there are more chili peppers that have been scarred by insects, making them more susceptible to the fungus, so they develop higher levels of capsaicin to fight off the fungus so more seeds survive.
Capsaicin also discourages other microbes, a fact that humans probably exploited by using them to preserve food long before there was refrigeration.