Chemical & Engineering News, the newsmagazine published by the American Chemical Society, the world's largest scientific society, in its Nov. 3 issue traces the pepper family history and explains why the vegetable can produce a fast burn.
Capsaicin is an extremely powerful and stable alkaloid produced as a crystal by glands at the junction of the pepper's placenta and pod walls, according to Dave DeWitt, known as the "Pope of Pepper" and publisher of Fiery Foods & BBQ magazine. The chemical is found only in chili peppers.
DeWitt says capsaicin puts the sting in pepper spray, is used in repellent sprays to protect gardens from animal pests, and chemists are now developing an environmentally safe marine coating made with capsaicin that will stop barnacles from growing. The chemical also stimulates circulation, triggers pain receptor cells to release helpful endorphins, and is used in various drugs to ease the pain of arthritis and other ailments, C&EN reports.
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, according to the newsmagazine. In 1846, L.T. Thresh reported in a published paper that the main chemical component of peppers could be removed in a crystalline state and he named this chemical capsaicin.
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, C&EN reports. And 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 haba¤ero peppers, compared to a mere 2,500 for the fabled jalapeño. Despite the high reading of 500,000, capsaicin in peppers is not likely to hurt anyone. The reading for pure capsaicin in the Scoville scale is 16 million.
In addition to pleasing many peoples' palates, chili peppers are a good source of vitamins A, C and E, rich in folic acid and potassium, low in calories and sodium, and contain no carbohydrates, C&EN says.
Another scientific fact imparted by the newsmagazine -- that capsaicin breaks down in fats -- is good news for dessert lovers who may need to turn down the pepper heat. That is, something cold, sweet and flavored with chocolate, vanilla, or strawberry certainly can help put out that fire.
For more details on hot peppers and other stories on the chemistry of everyday objects, go to http://www.cen-online.org and click on "What's That Stuff?", winner of a Scientific American Sci Tech Web Award for one of the best science websites for the public.