Chili pepper
The chili pepper, or more simply just "chili", is the fruit of the plants from the Genus Capsicum and the nightshade family, Solanaceae.
The name, which is spelled differently in many regions (chili, chile or chilli), comes from Nahuatl via the Spanish word chile. The term chili in most of the world refers exclusively to the smaller, hot types of capsicum. The mild larger types are called bell pepper in the USA, simply pepper in Britain and Ireland, capsicum in India and Australasia and paprika in many European countries.
Chili 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 as medicine.

# History
Chili peppers have been a part of the human diet in the Americas since at least 7500 BC and perhaps earlier. There is archaeological evidence at sites located in southwestern Ecuador that chili peppers were already well domesticated more than 6000 years ago , and is one of the first cultivated crops in the Americas.
Chili peppers are thought to have been domesticated at least five times by prehistoric peoples in different parts of South and North America, from Peru in the south to Mexico in the north and parts of Colorado and New Mexico (Ancient Pueblo Peoples).
In the publication Svensk Botanisk Tidskrift (1995), Professor Hakon Hjelmqvist published an article on pre-Columbian chili peppers in Europe. In an archaeological dig in the block of St. Botulf in Lund, archaeologists claimed to have found a Capsicum frutescens in a layer dating to the 13th century. Hjelmqvist also claims that Capsicum was described by the Greek Therophrasteus (370-286 BC). He also mentions other antique sources. The Roman poet Martialis (around the 1st century) described "Pipervee crudum" (raw pepper) to be long and containing seeds. The description of the plants does not fit pepper (Piper nigrum), which does not grow well in European climates. 
Christopher Columbus was one of the first Europeans to encounter them (in the Caribbean), and called them "peppers" because of their similarity in taste (though not in appearance) with the Old World peppers of the Piper genus.  Columbus was keen to propose that he had in fact opened a new direct nautical route to Asia, contrary to reality and the expert consensus of the time, and it has been speculated that he was therefore inclined to denote these new substances as "pepper" in order to associate them with the known Asian spice.
Chilis were cultivated around the globe after Columbus' time.  Diego Alvarez Chanca, a physician on Columbus' second voyage to the West Indies in 1493, brought the first chili peppers to Spain, and first wrote about their medicinal effects in 1494.
From Mexico, at the time the Spanish colony that controlled commerce with Asia, chili peppers spread rapidly into the Philippines and then to India, China, Korea and Japan with the aid of European sailors. The new spice was quickly incorporated into the local cuisines.
An alternate sequence for chili peppers' spread has the Portuguese picking up the pepper from Spain, and thence to India, as described by Lizzie Collingham in her book Curry.  The evidence provided is that the chili pepper figures heavily in the cuisine of the Goan region of India, which was the site of a Portuguese colony (e.g. Vindaloo, an Indian interpretation of a Portuguese dish).  Collingham also describes the journey of chili peppers from India, through Central Asia and Turkey, to Hungary, where it became the national spice in the form of paprika.
Currently India is the largest producer of Chillies with around one million tons per year, where the Guntur-Market (largest in Asia) alone processes one million bags(100lb each) .

# Species and cultivars
The most common species of chili peppers are:
- Capsicum annuum, which includes many common varieties such as bell peppers, paprika, cayenne, jalapenos, and the chiltepin
- Capsicum frutescens, which includes the tabasco peppers
- Capsicum chinense, which includes the hottest peppers such as the naga, habanero and Scotch bonnet
- Capsicum pubescens, which includes the South American rocoto peppers
- Capsicum baccatum, which includes the South American aji peppers
Though there are only a few commonly used species, there are many cultivars and methods of preparing chili peppers that have different common names for culinary use. Bell peppers, for example, are the same cultivar of C. annuum; immature peppers being green and mature peppers being red. In the same species are the jalapeno, the poblano (when dried is referred to as ancho), New Mexico (which is also known as chile colorado), 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, cherry peppers, malagueta and others.
Peppers are commonly broken down into three groupings: bell peppers, sweet peppers, and hot peppers. Most popular pepper varieties are seen as falling into one of these categories or as a cross between them.

# Intensity
The substances that gives chili peppers their intensity when ingested or applied topically are capsaicin (8-methyl-N-vanillyl-6-nonenamide) and several related chemicals, collectively called capsaicinoids. Capsaicin is the primary ingredient in pepper spray.
When consumed, capsaicinoids bind with pain receptors in the mouth and throat that are normally responsible for sensing heat. Once activated by the capsaicinoids, these receptors send a message to the brain that the person has consumed something hot. The brain responds to the burning sensation by raising the heart rate, increasing perspiration and releasing the body's natural painkilling chemical, endorphin.
The "heat" of chili peppers is measured in Scoville units (SHU). Bell peppers rank at 0 (SHU), New Mexico green chilis at about 1,500 SHU, jalapenos at 3,0006,000 SHU, and habaneros at 300,000 SHU. The record for the hottest chili pepper was assigned by the Guinness Book of Records to the Naga Jolokia, measuring over 1,000,000 SHU. Pure capsaicin, which is a hydrophobic, colorless, odorless, crystalline to waxy solid at room temperature, measures 16,000,000 SHU.

# Culinary use
The chili has a long association with Mexican cuisine as later adapted into Tex-Mex cuisine. Although unknown in Asia until Europeans introduced it there, chili has also become a part of the Korean, Indian, Indonesian, Szechuan, Thai and other cooking traditions. Its popularity has seen it adopted into many cuisines of the World.

### Chili fruit
The fruit is eaten raw or cooked for its fiery hot flavour 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. The white pith, that surrounds the seeds, contains the highest concentrations of capsaicin. Removing the seeds and inner membranes is thus effective at reducing the heat of a pod.
Chili is often sold worldwide as a spice in dried and powdered form. In the United States, it is often made from the Mexican chile ancho variety, but with small amounts of cayenne added for heat. In the Southwest United States, dried ground chili peppers, cumin, garlic and oregano is often known as chili powder. Chipotles are dry, smoked red (ripe) jalapenos.
Chili peppers are also often used around the world to make a wide variety of sauces, known as hot sauce, chili sauce, or pepper sauce. There are countless recipes.
Indian cooking has multiple uses for chilies, from snacks like bajji where the chilies are dipped in batter and fried to the infamously hot vindaloo. Chilies are also dried and roasted and salted for later use as a side dish for rice varieties like vadam (a kind of pappad). In Turkish or Ottoman cuisine, chilies are widely used where it is known as Krmz Biber (Red Pepper) or Ac Biber (Hot Pepper). Sambal is dipping sauce made from chili peppers with many other ingredients such as garlic, onion, shallots, salt, vinegar and sugar, which is very popular in Indonesia, Malaysia and Singapore. Chili powder is an important spice in Persian cuisine and is used moderately in a variety of dishes.

### Chili leaves
The leaves of the chili pepper plant, which are mildly bitter, are cooked as greens in Filipino cuisine, where they are called dahon ng sili (literally "chili leaves").  They are often used in the chicken soup dish known as tinola. In Korean cuisine, the leaves are also used to produce kimchi ( ).

# Decoration
There are entire breeds of chili pepper which are not intended for consumption at all, but are grown only for their decorative qualities, generally referred to as "ornamental peppers". Some of them are too hot for most common cooking techniques, or simply don't taste good. Some are grown for both decoration and food. Either way, they tend to have peppers of unusual shapes or colors. Examples of these include Thai Ornamental, Black Pearl, Marble, Numex Twilight, and the Medusa pepper. Numex Twilight is a green plant which produces fruit starting purple, then ripening to yellow, orange, and red. Black Pearl has black leaves and round red fruit. In India, the chili, along with lime is used to ward off evil spirits and is often seen in vehicles and in homes to that effect. It is also used to check the evil eye and remove its effects in Hinduism as people will also be asked to spit into a handful of chilies kept in that plate, which are then thrown into fire. If the chilies make a noise - as they should - then there is no case of "drishti" (evil eye); if on the other hand they don't make any sound, then the spell of the evil eye is removed in the fire.

# Popularity
Chili peppers are popular in food. They are rich in vitamin C and are believed to have many beneficial effects on health. Psychologist Paul Rozin suggests that eating chilis is an example of a "constrained risk" like riding a roller coaster, in which extreme sensations like pain and fear can be enjoyed because individuals know that these sensations 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. Chili peppers are in fact a favorite food of many birds living in the chili peppers' natural range. The flesh of the peppers provides the birds with a nutritious meal rich in vitamin C. In return, the seeds of the peppers are distributed by the birds, 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.

# Spelling and usage
The three primary spellings are chili, chile and chilli, all of which are recognized by dictionaries.
- Chili is widely used, but this spelling is discouraged by some, since it is more commonly used to refer to a popular Southwestern-American dish (also known as chili con carne (literally chili with meat), the official state dish of Texas), as well as to the mixture of cumin and other spices (chili powder) used to flavor it. Chili powder and chile powder, on the other hand, can both refer to dried, ground chili peppers.
- Chile is the American spelling (uncommon elsewhere) which refers specifically to this plant and its fruit. This orthography is common in much of the Spanish-speaking world, although in much of South America the plant and its fruit are better known as aji and locoto or rocoto. In the American southwest (particularly northern New Mexico), chile also denotes a thick, spicy, un-vinegared sauce, which is available in red and green varieties and which is often served over most New Mexican cuisine.
- Chilli was the original Romanization of the Aztec word for the fruit and is the preferred spelling according to the Oxford English Dictionary, although it also lists chile and chili as variants.
The name of this plant bears no relation to Chile, the country, which is named after the Quechua chin ("cold"), tchili ("snow"), or chilli ("where the land ends"). Chile is one of the Spanish-speaking countries where chilis are known as aji, a word of Taino origin.
There is some disagreement about whether it is proper to use the word "pepper" when discussing chili peppers because "pepper" originally referred to the genus Piper, not Capsicum. Despite this dispute, a sense of pepper referring to Capsicum is supported by English dictionaries, including the Oxford English Dictionary (sense 2b of pepper) and Merriam-Webster. Furthermore, the word "pepper" is commonly used in the botanical and culinary fields in the names of different types of chili peppers.

# Nutritional value
Red chilis contain some amounts of vitamin C and provitamin A. Yellow and especially green chilis (which are essentially unripe fruit) contain a considerably lower amount of both substances. In addition, peppers are a good source of most B vitamins, and vitamin B6 in particular. They are very high in potassium and high in magnesium and iron. Their high vitamin C content can also substantially increase the uptake of non-heme iron from other ingredients in a meal, such as beans and grains.

# Possible health benefits
All chili peppers contain phytochemicals known collectively as capsaicinoids.
- Capsaicins have been shown, in laboratory settings, to shrink cancerous tumors in rats with minimal side-effects.
- Recent research in mice shows that chilli (capsaicin in particular) may offer some hope of weight loss for people suffering from obesity.
- Canadian researchers used capsaicin from chillies to kill nerve cells in the pancreases of mice with Type 1 diabetes, thus allowing the insulin producing cells to start producing insulin again.
- Research in humans found that "after adding chili to the diet, the LDL, or bad cholesterol, actually resisted oxidation for a longer period of time, (delaying) the development of a major risk for cardiovascular disease".
- Australian researchers at the University of Tasmania found that the amount of insulin required to lower blood sugar after a meal is reduced if the meal contains chili pepper.
- Chilli peppers are being probed as a treatment for alleviating chronic pain.
- Spices, including chilli, are theorized to control the microbial contamination levels of food in countries with minimal or no refrigeration.
- Hot peppers can provide symptomatic relief from rhinitis and possibly bronchitis by thinning and clearing mucus from stuffed noses or congested lungs.

# Precautions
- Chronic ingestion of chilli products may induce gastroesophageal reflux (GER).
- Chilli may increase the number of daily bowel movements and lower pain thresholds for people with irritable bowel syndrome.
- A high consumption of chilli is associated with stomach cancer.
- Chillis should never be swallowed whole; there are cases where unchewed chillis have caused bowel obstruction and perforation.
- Consumption of red chillies after anal fissure surgery should be forbidden to avoid postoperative symptoms.
- Chillis may sometimes be adulterated with Sudan I, II, III IIV, para-Red, and other illegal dyes.
- Aflatoxins and N-nitroso compounds, which are carcinogenic, are frequently found in chilli powder.