Capsaicin

Introduction
Capsaicin is the active component of chili peppers, which are  plants belonging to the genus Capsicum. It is an irritant for mammals, including humans, and produces a sensation of burning in any tissue with which it comes into contact. Capsaicin and several related compounds are called capsaicinoids and are produced as a secondary metabolite by chili peppers, probably as deterrents against certain herbivores and fungi.  Pure capsaicin is a hydrophobic, colorless, odorless, crystalline to waxy compound.
 
Capsaicin is the main capsaicinoid in chili peppers, followed by dihydrocapsaicin. these two compounds are also about twice as potent to the taste and nerves as the minor capsaicinoids nordihydrocapsaicin, homodihydrocapsaicin, and homocapsaicin. Dilute solutions of pure capsaicinoids produced different types of pungency; however, these differences were not noted using more concentrated solutions.

Function
1) Food Industry
Because of the burning sensation caused by capsaicin when it comes in contact with mucous membranes, it is commonly used in food products to give them added spice or "heat" (piquancy). In high concentrations, capsaicin will also cause a burning effect on other sensitive areas of skin. The degree of heat found within a food is often measured on the Scoville scale. In some cases people enjoy the heat; there has long been a demand for capsaicin-spiced food and beverages. 

2) Medical Industry
Capsaicin is currently used in topical ointments, as well as a high-dose dermal patch (trade name Qutenza), to relieve the pain of peripheral neuropathy such as post-herpetic neuralgia caused by shingles.It may be used in concentrations of between 0.025% and 0.15%.

Basic Information