Capsaicin, only found in chili peppers, is an extremely powerful and stable alkaloid produced as a crystal by glands at the junction of the pepper's placenta and pod walls, said Dave DeWitt in recent article for the American Chemical Society.
According to DeWitt, the exploration of the chemistry of capsaicin dates to 1816 when P.A. Bucholtz found that the pungent principle of peppers could be extracted from the pods using organic solvents.
In 1846, L.T. Thresh reported in a published paper that the main chemical component of peppers - that he called capsaicin - could be removed in a crystalline state.
The article, published in this month's issue of Chemical & Engineering News, states that the most well known lab work on the chemical was done by Wilbur Scoville, who in 1912 convened a panel of tasters, who rated the heat of different peppers. Today the Scoville scale of units is the 'rule of tongue' for rating pepper heat. For pepper lovers, the hottest rating - at 300,000-500,000 - goes to habanero peppers, compared to a mere 2,500 for the fabled jalapeño. And there is hotter - the reading for pure capsaicin in the Scoville scale is 16 million.
In addition to warming the palates of populations around the globe, chili peppers are a good source of vitamins A, C and E, rich in folic acid and potassium, low in calories and sodium, contain no carbohydrates and could help to break down fats, said DeWitt.