The tomato is the edible berry of the plant Solanum lycopersicum, commonly known as the tomato plant. The species originated in western South America and Central America. The Mexican Nahuatl word tomatl gave rise to the Spanish word tomate, from which the English word tomato derived. Its domestication and use as a cultivated food may have originated with the indigenous peoples of Mexico. The Aztecs used tomatoes in their cooking at the time of the Spanish conquest of the Aztec Empire, and after the Spanish encountered the tomato for the first time after their contact with the Aztecs, they brought the plant to Europe, in a widespread transfer of plants known as the Columbian exchange. From there, the tomato was introduced to other parts of the European-colonized world during the 16th century.
Numerous varieties of the tomato plant are widely grown in temperate climates across the world, with greenhouses allowing for the production of tomatoes throughout all seasons of the year. Tomato plants typically grow to 1–3 meters (3–10 ft) in height. They are vines that have a weak stem that sprawls and typically needs support. Indeterminate tomato plants are perennials in their native habitat, but are cultivated as annuals. (Determinate, or bush, plants are annuals that stop growing at a certain height and produce a crop all at once.) The size of the tomato varies according to the cultivar, with a range of 1–10 cm (1⁄2–4 in) in width.
Classification
In 1753, Linnaeus placed the tomato in the genus Solanum (alongside the potato) as Solanum lycopersicum. In 1768, Philip Miller moved it to its own genus, naming it Lycopersicon esculentum. The name came into wide use, but was technically in breach of the plant naming rules because Linnaeus's species name lycopersicum still had priority. Although the name Lycopersicum lycopersicum was suggested by Karsten (1888), it is not used because it violates the International Code of Nomenclature barring the use of tautonyms in botanical nomenclature. The corrected name Lycopersicon lycopersicum (Nicolson 1974) was technically valid, because Miller's genus name and Linnaeus's species name differ in exact spelling, but since Lycopersicon esculentum has become so well known, it was officially listed as a nomen conservandum in 1983, and would be the correct name for the tomato in classifications which do not place the tomato in the genus Solanum.
Consumption
The tomato is now grown and eaten around the world. It is used in diverse ways, including raw in salads or in slices, stewed, incorporated into a wide variety of dishes, or processed into ketchup or tomato soup. Unripe green tomatoes can also be breaded and fried, used to make salsa, or pickled. Tomato juice is sold as a drink, and is used in cocktails such as the Bloody Mary.
Storage
Tomatoes keep best unwashed at room temperature and out of direct sunlight. It is not recommended to refrigerate them as this can harm the flavour. Tomatoes stored cold tend to lose their flavour permanently. Storing stem down can prolong shelf life, as it may keep from rotting too quickly. Tomatoes that are not yet ripe can be kept in a paper bag till ripening. Tomatoes are easy to preserve whole, in pieces, as tomato sauce or paste by home canning. They are acidic enough to process in a water bath rather than a pressure cooker as most vegetables require. The fruit is also preserved by drying, often in the sun, and sold either in bags or in jars with oil.
Safety
Plant toxicity. The leaves, stem, and green unripe fruit of the tomato plant contain small amounts of the alkaloid tomatine, whose effect on humans has not been studied. They also contain small amounts of solanine, a toxic alkaloid found in potato leaves and other plants in the nightshade family. However, solanine concentrations in foliage and green fruit are generally too small to be dangerous unless large amounts are consumed—for example, as greens.
Salmonella. Tomatoes were linked to seven Salmonella outbreaks between 1990 and 2005, and may have been the cause of a salmonellosis outbreak causing 172 illnesses in 18 US states in 2006. The 2008 United States salmonellosis outbreak caused the temporary removal of tomatoes from stores and restaurants across the United States and parts of Canada, although other foods, including jalapeño and serrano peppers, may have been involved.
Nutrition
A tomato is 95% water, contains 4% carbohydrates and less than 1% each of fat and protein (table). 100 g of raw tomatoes supply 18 kilocalories and are a moderate source of vitamin C (17% of the Daily Value), but otherwise have no significant nutrient content.
Pictures
Table
| Tomato | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Solanales |
| Family: | Solanaceae |
| Genus: | Solanum |
| Species: | S. lycopersicum |
| Binomial name | |
| Solanum lycopersicum | |
| Synonyms[1] | |
Lycopersicon lycopersicum (L.) H. Karst. | |
| Nutritional value per 100 g (3.5 oz) | |
|---|---|
| Energy | 74 kJ (18 kcal) |
3.9 g | |
| Sugars | 2.6 g |
| Dietary fiber | 1.2 g |
0.2 g | |
0.9 g | |
| Vitamins | Quantity %DV† |
| Vitamin A equiv. | 5% 42 μg4% 449 μg123 μg |
| Thiamine (B1) | 3% 0.037 mg |
| Riboflavin (B2) | 2% 0.019 mg |
| Niacin (B3) | 4% 0.594 mg |
| Pantothenic acid (B5) | 2% 0.089 mg |
| Vitamin B6 | 6% 0.08 mg |
| Folate (B9) | 4% 15 μg |
| Vitamin C | 17% 14 mg |
| Vitamin E | 4% 0.54 mg |
| Vitamin K | 8% 7.9 μg |
| Minerals | Quantity %DV† |
| Calcium | 1% 10 mg |
| Iron | 2% 0.27 mg |
| Magnesium | 3% 11 mg |
| Manganese | 5% 0.114 mg |
| Phosphorus | 3% 24 mg |
| Potassium | 5% 237 mg |
| Sodium | 0% 5 mg |
| Zinc | 2% 0.17 mg |
| Other constituents | Quantity |
| Water | 94.5 g |
| Lycopene | 2573 μg |
| |
| †Percentages are roughly approximated using US recommendations for adults. Source: USDA FoodData Central | |