The chile pepper, chili pepper or chilli pepper is the fruit of the plant Capsicum from the nightshade family, Solanaceae. The name comes from Nahuatl via the Spanish word chile. Chile peppers and their various cultivars originate in the Americas; they are now grown around the world because they are widely used as spices or vegetables in cuisine, and even as medicine. 

History 

Chile peppers have been a part of the human diet in the Americas since about 7500 BC. They were domesticated there between 5200 and 3400 BC, one of the first cultivated crops in the Americas. Chile peppers are thought to have been domesticated at least five times by prehistoric peoples in different parts of South and Middle America, from Peru in the south to Mexico in the north. 

They were discovered in the Caribbean by Columbus and named "peppers" because of their similarity in taste (though not in appearance) with the Old World peppers of the Piper genus. 

Diego Álvarez Chanca, a physician on Columbus' second voyage to the West Indies in 1493, brought the first chile peppers to Spain, and first wrote about their medicinal effects in 1494. 

From Europe, chili peppers spread rapidly into India, China, and Japan. The new spice was quickly incorporated into the local cuisines. 

Species and cultivars 

The most common species of chile peppers are: 

Capsicum annuum, which includes many common varieties such as bell peppers, paprika, and jalapeños

Capsicum frutescens, which includes the cayenne and tabasco peppers

Capsicum chinense, which includes the hottest peppers such as habaneros and Scotch bonnets

Capsicum pubescens, which includes the South American rocoto peppers

Capsicum baccatum, which includes the chiltepin  

Though there are only a few commonly used species, there are many cultivars and methods of preparing chile peppers that have different common names for culinary use. Green and red bell peppers, for example, are the same cultivar of C. annuum, the green ones being immature. In the same species are the jalapeño, the chipotle (a smoked jalapeño), the poblano, ancho (which is a dried poblano), New Mexico, Anaheim, Serrano, and other cultivars. Jamaicans, Scotch bonnets, and habaneros are common varieties of C. chinense. The species C. frutescens appears as chiles de arbol, aji, pequin, tabasco, cayenne, cherry peppers, and others. 

Heat 

The substances that give chili peppers their heat are the alkaloid capsaicin (8-methyl-N-vanillyl-6-nonenamide or C18H27NO3) and four related chemicals, collectively called capsaicinoids. Each capsaicinoid has a different effect on the mouth, and variation in the proportions of this chemical is responsible for the differing sensations produced by different varieties. Capsaicin causes pain and inflammations if consumed to excess, and can even burn the skin on contact in high concentrations (habanero peppers, for example, are routinely picked with gloves). It is also the primary ingredient in pepper spray, which is used as a "less-than-lethal" weapon. 

The "heat" of chile peppers is measured in Scoville units. Bell peppers rank at zero Scoville units, jalapeños at 3,000–6,000 Scoville units, and habaneros at 300,000 Scoville units. The Guinness Book of Records assigns the record for the highest number of Scoville units in a chile pepper to the Red Savina Habanero, measuring 577,000 units. However, a recent report was made of a pepper from India called the Naga Jolokia measuring at 855,000 Scoville units. Both the Red Savina and the Naga Jolokia claims are disputed as to their validity, and lack independent verification. Pure capsaicin rates at 16,000,000 Scoville units. 

Cuisine 

The fruit is eaten cooked or raw for its fiery hot flavor, which is concentrated along the top of the pod. The stem end of the pod has glands, which produce the capsaicin, which then flows down through the pod. Removing the seeds and inner membranes is thus effective at reducing the heat of a pod. 

Well-known dishes with a strong chile flavor are Mexican salsas, Tex-Mex chili con carne, and Indian vindaloos and other curries. Chili powder is a spice made of the dried ground chiles, usually of the Mexican chile ancho variety, but with small amounts of cayenne added for heat. Bottled hot sauces such as Tabasco sauce are made from chilies such as the cayenne (not, oddly, from tabasco peppers), which may also be fermented. 

Indonesian, Indian, Szechuan and Thai cuisines are particularly associated with the chile pepper, although the plant was unknown in Asia until Europeans introduced it there. 

Sambal is dipping sauce made from chile peppers with any other ingredients such as garlic, onion, shallots, salt, vinegar and sugar. It is very popular in Indonesia, Malaysia and Singapore. 

Popularity 

Chile peppers are popular in food, despite the pain and irritation they bring. Capsaicin has an antibacterial effect, so food cooked with chilies keeps for longer without spoiling. They are rich in vitamin C and are believed to have many beneficial effects on health. The pain caused by capsaicin stimulates the brain to produce endorphins, natural opioids that act as analgesics and produce a sense of well-being. Psychologist Paul Rozin suggests that eating chilies is an example of a "constrained risk" like riding a roller coaster, in which extreme sensations like pain and fear can be enjoyed because we know they are not actually harmful.  

Birds do not have the same sensitivity to capsaicin as mammals, as capsaicin acts on a specific nerve receptor in mammals, and avian nervous systems are rather different. Chile peppers are in fact a favorite food of many birds living in the chile peppers' natural range. The flesh of the peppers provides the birds with nutritious meal rich in vitamin C. In return, the birds distribute the seeds of the peppers, as they drop the seeds while eating the pods or the seeds pass through the digestive tract unharmed. This relationship is theorized to have promoted the evolution of the protective capsaicin. It is interesting to note that the chemical used to give an artificial grape flavoring to food items such as grape soda does have a similar effect on birds as capsaicin has on humans.