Information and uses for capsaicinoids (Hot Peppers)!!
How hot is that chili pepper? Until recently, the answer has been totally subjective—one person’s hot sauce might be another person’s mild. Hot sauce manufacturers require more reliable “heat” levels for their products. They need a measurement process that is more objective. The traditional method for determining heat levels was to use a panel of professional tasters and their tongues. Hot sauces are diluted with sweetened water until the hotness cannot be tasted. Generally, the more dilution needed, the higher the spice, and thus the higher the heat level. This level is then expressed in the Scoville Organoleptic Scale, first devised by pharmacist Wilbur Scoville in 1912, from which the world’s peppers are rated. Peppers’ heat levels vary widely from zero units for bell peppers to a mouth-searing 300,000 Scoville heat units for habaneros.

Obviously, the taste panel test is imprecise, time-consuming, subjective, and very costly. A more reliable test, one with repeatable results, was needed for manufacturers. HPLC is that very method.

What makes them hot!!!
What causes the “heat” in peppers? All hot peppers belonging to the genus capsicum, which includes red peppers, tabascos, habaneros, and paprika, contain capsaicinoids that produce a burning sensation in the mouth by acting directly on the pain receptors in the mouth and throat. At higher levels, they cause the eyes to water and the nose to run, and they often induce perspiration. There are five common naturally occurring capsaicinoids. The primary capsaicinoid, capsaicin, is so hot (rated at 16 million Scoville units) that a single drop diluted in 100,000 drops of water will produce a blistering of the tongue. Capsaicin is 70 times hotter than piperine, the spicy principal in black pepper, and 1000 times stronger than zingerone, the active ingredient of ginger. It is barely soluble in water but is very soluble in oils or alcohols.

The second most common capsaicinoid, is just as hot. Together, these two comprise 80–90% of the total capsaicinoids found in peppers. Others are nordihydrocapsaicin (NDC), homocapsaicin (HC), and homodihydrocapsaicin (HDC), with Scoville ratings ranging from 6.9 million to 9.3 million units.
Capsaicinoids are found primarily in the pepper’s placenta, the white “ribs” that run down the middle and along the sides of a pepper. Because the seeds are in close contact with the ribs, they are also often hot. Caution should be exercised in handling some of the more fiery peppers as their juice can burn the skin and damage the eyes. Because capsaicins are not water-soluble, drinking milk (with milk fat and proteins) rather than water is a more effective way to quench the fire caused by hot peppers.

Measuring the HEAT!!!
Because common capsaicinoids differ by either the carbon chain length or the presence of a double bond, they can be readily separated and their relative “burning sensations” measured. The overall heat level of the hot sauce or the pepper extract is then calculated by the summation of each contributing component (derived by multiplying the concentration of each capsaicinoid with its respective Scoville rating).

Other Uses of Capsaicin
Are hot peppers bad for you? Contrary to the common belief that spicy foods cause ulcers, studies have found no increased incidence of stomach ulcers in countries of high pepper consumption such as Brazil or Thailand. Because they interact with pain receptors and desensitize them through repeated contact, capsaicins are used in over-the-counter dermatological ointments (0.025%) for the relief of itchy skin, psoriasis, shingles, muscle aches, or pain from osteoarthritis and rheumatoid arthritis. New salves for AIDS patients to alleviate leg pain are in development. Capsaicin also has a rich history in alternative medicine. Reported benefits include antimicrobial, anticoagulant, or anti-inflammatory properties and the ability to promote circulation or to relieve cold symptoms by clearing the sinus. Capsaicins are even used in the pest control industry to ward off insects such as ground crawling ones like ants and beetles. Studies are under way to investigate whether capsaicin can increase the metabolism of body fat by raising metabolic rate and body temperature. Capsaicin is also the active ingredient in pepper spray, an effective crime fighter, though its use is regulated or banned in many areas. Additional novel applications include its use as a rodent repellent (especially potent for pesky squirrels near bird feeders) and for the prevention of dog fights or swine cannibalism. For genuine “chiliheads”, a capsaicin-based toothpaste is available to “burn” away cavities.

The Future For Heat Units
So what’s in the future for “heat” testing? No doubt Scoville units are easier to handle than a panel of tasters; and it never suffers from taste fatigue. Perhaps there should be the use of Scoville units in every restaurant serving serious spicy cuisine—imagine menus posting guaranteed Scoville ratings instead of untrustworthy numbers of red pepper icons. Perhaps new pepper test strips, similar to pH papers, should be offered for discriminating customers who wish to double-check their meals. Maybe and maybe not…we shall see how the world’s taste evolves in the new millennium.