Cayenne pepper is a hot red pepper used to flavor dishes; its name comes from the city of Cayenne in French Guiana. Its powdered form comes from the fruit of several cultivated varieties of the Capsicum baccatum and Capsicum frutescens very closely related to bell peppers, jalapeños, paprika, and others. All are related species of the nightshade family (Solanaceae).
The fruits are generally dried and ground, or pulped and baked into cakes, which are then ground and sifted to make the powder.
Cayenne Scoville Rating
Cayenne is used in cooking spicy hot dishes, as a powder or in its whole form (such as in Szechuan cuisine). It is generally rated at 40,000 to 90,000 Scoville Units. It is also used as an herbal supplement, and was mentioned by Nicholas Culpeper in his Complete Herbal.
Additionally, cayenne has many beneficial medicinal qualities. Cayenne is a traditional treatment, as well as modern, most notably for the pulmonary and digestive systems.
Cayenne contains a resin like pungent substance known as capsaicin. This chemical relieves pain and itching by affecting sensory nerves. Capsaicin temporarily causes the nerves to release various neurotransmitters from these nerves, leading to their depletion. Without the neurotransmitters, pain signals can no longer be sent. The effect is temporary. Capsaicin and other constituents in cayenne have been shown to have several other actions, including reducing platelet stickiness and acting as antioxidants.