Heat in hot peppers, where does it come from and why? I have just been reading a very erudite report at Harvard University about the origin of heat in peppers. It amazed me that all the pepper lovers in the world only got what they love, by a tiny change that a primitive early ancestor of peppers made to protect itself from attack by predators.
It seems that there are two factors at work, one is that rodents eat peppers and love them and they have such fine teeth they eat the seeds to the point they cannot germinate whereas birds eat the flesh and drop the seeds. So the plant developed a small metabolic change to create capsaicin the heat in peppers as the birds don’t taste the heat but rats do, so this deterred the rats. Pepper plants are also attacked by insects that suck the juices, and this defence also deters them.
The second is mould. Now peppers grow in moist environments and are very prone to mould and fungus, which attacks the buds and stops the peppers growing. Capsaicin deters mould and fungus so stops that attack as well. We notice this as when we age our peppers over two to three years, not only do we notice no deterioration, but laboratory analysis confirms that the peppers stay pure which explains our two year shelf life.
The article points out that the peppers pay a price for the defence. Producing the complex molecules for heat weakens the plants water retention capability and pepper plants with heat are much less resistant to drought than sweet peppers. Its a trade off they have made over time, but are we not so grateful. Without this development we would not have our hot sauce.
LINK TO ARTICLE