Black pepper, or Piper nigrum, is a perennial flowering vine in the family Piperaceae discovered on the Malabar Coast of India, known today as Kerala. This tropical plant grows up to 30 feet high and is cultivated in India and Southeast Asia. Today, black pepper is the world's most traded spice, and accounts for one-fifth of the world's spice trade. Currently Vietnam is the world's largest producer and exporter of pepper, producing 34% of the world's Piper nigrum crop as of 2008.
The fruit of the pepper plant, when dried, is called a peppercorn. A pepper plant takes four years to mature, but can be harvested for seven years afterward. You can tell that peppercorns are ready for harvest when one or two clusters of fruit on a low-hanging stem begin to turn red. Once harvested, they are dried by either the sun or a machine.
There are three kinds of peppercorns — black (cooked and dried unripe fruit), green (dried unripe fruit) and white (ripe fruit seeds) — all harvested from the same plant variety, but processed in different ways.
Dried ground pepper has been used since antiquity for both its flavor and as a traditional medicine. It is one of the most common spices added to European cuisine and its descendants. The spiciness of black pepper is due to the chemical piperine, not to be confused with the capsaicin that gives fleshy peppers theirs. It is ubiquitous in the modern world as a seasoning, and is often paired with salt.
Pepper gets its spicy heat mostly from piperine derived both from the outer fruit and the seed. Refined piperine, by weight, is about one percent as hot as the capsaicin found in chili peppers. The outer fruit layer, left on black pepper, also contains important odour-contributing terpenes including pinene, sabinene, limonene, caryophyllene, and linalool, which give citrusy, woody, and floral notes. These scents are mostly missing in white pepper, which is stripped of the fruit layer.
One tablespoon (6 grams) of ground black pepper contains moderate amounts of vitamin K (13% of the Daily Value or DV), iron (10% DV) and manganese (18% DV), with trace amounts of other essential nutrients, protein and dietary fibre.
Black Pepper (or perhaps long pepper) was believed to cure illness such as constipation, diarrhoea, earache, gangrene, heart disease, hernia, hoarseness, indigestion, insect bites, insomnia, joint pain, liver problems, lung disease, oral abscesses, sunburn, tooth decay, and toothaches. Various sources from the 5th century onward also recommend pepper to treat eye problems, often by applying salves or poultices made with pepper directly to the eye. There is no current medical evidence that any of these treatments has any benefit; pepper applied directly to the eye would be quite uncomfortable and possibly damaging. Nevertheless, black pepper, either powdered or its decoction, is widely used in traditional Indian medicine and as a home remedy for relief from sore throat, throat congestion, cough etc.
Piperine is under study for its potential to increase absorption of selenium, vitamin B, beta-carotene and curcumin as well as other nutrients. As a folk medicine, pepper appears in the Buddhist Samaññaphala Sutta, chapter five, as one of the few medicines allowed to be carried by a monk.
Pepper contains phytochemicals, including amides, piperidines, pyrrolidines and trace amounts of safrole which may be carcinogenic in laboratory rodents.