All About Chili Peppers

The chili pepper, chile pepper or chilli pepper, or simply chili, chile or chilli, is the fruit of the plant Capsicum from the nightshade family, Solanaceae. The name comes from Nahuatl via the Spanish word chile. These terms usually refer to the smaller, hotter types of capsicum; the mild larger types are called bell pepper (simply pepper in Britain and Ireland or capsicum in Australasia).

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.

Origins and History
Chili 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. Chili peppers are thought to have been domesticated at least five times by prehistoric peoples in different parts of South, Central and North America, from Peru in the south to Mexico in the north and parts of Colorado and New Mexico (Ancient Pueblo Peoples).

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 prove (incorrectly) 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 "pepper" in order to associate them with the known Asian spice.

Diego Álvarez 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 pepper's 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.

Hot peppers and their biological effects
Chili peppers are well known for their pungency, which comes from a compound called capsaicin (8-methyl-N-vanillyl-6-nonenamide) and several related chemicals, collectively called capsaicinoids. Especially in countries with a hot climate, hot peppers have become a central part of the cuisine. It is commonly said that spicy food helps a person “cool off”, which could be explained by the vasodilatory effect of capsaicin, shown to lower the skin temperature of humans exposed to a hot environment [Nelson AG, 2000]. In more temperate surroundings, to make up for the lost heat, and because of direct effects of capsaicin, this vasodilatation is generally accompanied by an increase in metabolism (thermogenesis) [Yoshioka 1998], which may contribute to the feeling of vigor and comfort some people experience after a spicy dish.

The breeding of sweet peppers and CH-19 Sweet
Not everyone likes spicy food, and for centuries humans have selectively bred sweet (non-pungent) peppers from hot peppers. Sweet peppers do not contain capsaicin and are a prized ingredient in salads and other dishes for their crisp substance and fresh flavor. In 1989, selectively breeding a Thai variety of hot peppers to obtain a non-pungent variety, a Japanese group of plant biologists made a startling discovery [Yazawa, 1989]. The fruits they had bred, which they named “CH-19 Sweet”, differed markedly from other sweet peppers. CH-19 Sweet was found to contain a substance closely related to capsaicin, but without its pungency. This substance was named capsiate. If pure capsaicin and capsiate are diluted in water, it takes 1000 times as much capsiate before a person can taste it. In addition to capsiate, CH-19 Sweet contained smaller amounts of dihydrocapsiate and nordihydrocapsiate (see figure). Together these three compounds were named capsiniods. The existence of these three substances in CH-19 Sweet is analogous to capsaicin-containing fruits, which also contain dihydrocapsaicin and nordihydrocapsaicin. Later studies would show that common varieties of hot peppers also contain small amounts of capsinoids.

Measuring heat
The "heat" of chile peppers is measured in Scoville units (SHU). Bell peppers rank at 0 (SHU), jalapeños at 3,000–6,000 SHU, and habaneros at 300,000 SHU. The record for the hottest chili pepper is assigned by the Guinness Book of Records to the Red Savina Habanero, measuring 577,000 SHU; however the Dorset Naga pepper is claimed to be over three times as hot as the Red Savina pepper, at 970,000 SHU.

However, a recent report was made of a pepper from India called the Naga Jolokia, measuring at 855,000 SHU. Both the Red Savina and the Naga Jolokia claims are disputed as to their validity, and lack independent verification. In April 2006, it was reported that the Dorset Naga pepper, a variety of the Naga Jolokia pepper cultivated exclusively by the Peppers by Post company in Dorset, England, had been measured at 923,000 SHU by a lab used by the American Spice Trade Association. For reference, pure capsaicin rates at 15,000,000-16,000,000 SHU. Subsequently BBC “Gardeners’ World” has recorded an even higher level for the Dorset Naga. As part of its 2006 programming, it ran a chili trial looking at several varieties. Heat levels were tested in a British laboratory and the Dorset Naga came in at almost 1.6 million SHU. The growers are currently waiting for details of the testing before being confident with this result.

Some speculate that chiles evolved pungency to protect the fruits from being eaten by mammals. Capsaicinoids are the only alkaloid chile produces. Birds, the natural dispersal agent of chiles, can not feel the heat and thus disseminate the seeds; however, when mammals eat chiles the seeds are destroyed in the digestive tract.;
New Mex. State Univ, 2007

Information Sources

Nelson AG, et al., The effect of capsaicin on the thermal and metabolic responses of men exposed to 38 degrees C for 120 minutes. Wilderness Environ Med. 11:152-156, 2000 Fall.

New Mexico State University,, 2007.

Yazawa S, et al., Content of capsiaicinoids and capsaicinoid-like substances in fruit of pepper (Capsicum annum L.) hybrids made with “CH-19 Sweet as a parent. J Jpn Soc Hortic Sci 58:601-607, 1989.

Yoshioka M, et al., Effects of red pepper added to high-fat and high-carbohydrate meals on energy metabolism and substrate utilization in Japanese women. Br J Nutr 80:503-510, 1998.