Broccoli is a edible green plant in the cabbage family, whose large flower head is used as a vegetable. The word broccoli, from the Italian plural of broccolo, refers to "the flowering top of a cabbage". Broccoli is usually boiled or steamed but may be eaten raw and has become popular as a raw vegetable in hors d'œuvre trays. The leaves may also be eaten.
Broccoli is classified in the Italica cultivar group of the species Brassica oleracea. Broccoli has large flower heads, usually green in color, arranged in a tree-like structure on branches sprouting from a thick, edible stalk. The mass of flower heads is surrounded by leaves. Broccoli most closely resembles cauliflower, which is a different cultivar group of the same species.
Broccoli is a man-made plant  , derived from careful breeding of cultivated leafy cole crops in the Northern Mediterranean in about the 6th century BCE. Since the Roman Empire, broccoli has been considered a uniquely valuable food among Italians. Broccoli was brought to England from Antwerp in the mid-18th century by Peter Scheemakers. Broccoli was first introduced to the United States by Italian immigrants but did not become widely known there until the 1920s.
Broccoli is high in vitamin C and dietary fiber; it also contains multiple nutrients with potent anti-cancer properties, such as diindolylmethane and small amounts of selenium. A single serving provides more than 30 mg of vitamin C and a half-cup provides 52 mg of vitamin C. The 3,3'-Diindolylmethane found in broccoli is a potent modulator of the innate immune response system with anti-viral, anti-bacterial and anti-cancer activity. Broccoli also contains the compound glucoraphanin, which can be processed into an anti-cancer compound sulforaphane, though the benefits of broccoli are greatly reduced if the vegetable is boiled. Broccoli is also an excellent source of indole-3-carbinol, a chemical which boosts DNA repair in cells and appears to block the growth of cancer cells.
Boiling broccoli reduces the levels of suspected anti-carcinogenic compounds, such as sulforaphane, with losses of 20–30% after five minutes, 40–50% after ten minutes, and 77% after thirty minutes. However, other preparation methods such as steaming,microwaving, and stir frying had no significant effect on the compounds.
There are three commonly grown types of broccoli. The most familiar is Calabrese broccoli, often referred to simply as "broccoli", named after Calabria in Italy. It has large (10 to 20 cm) green heads and thick stalks. It is a cool season annual crop. Sprouting broccoli has a larger number of heads with many thin stalks. Purple cauliflower is a type of broccoli sold in southern Italy, Spain, and the United Kingdom. It has a head shaped like cauliflower, but consisting of tiny flower buds. It sometimes, but not always, has a purple cast to the tips of the flower buds.
Other cultivar groups of Brassica oleracea include cabbage (Capitata Group), cauliflower and Romanesco broccoli (Botrytis Group), kale and collard greens (Acephala Group), kohlrabi (Gongylodes Group), and Brussels sprouts (Gemmifera Group). Chinese broccoli (Alboglabra Group) is also a cultivar group of Brassica oleracea.Rapini, sometimes called "broccoli rabe" among other names, forms similar but smaller heads, and is actually a type of turnip (Brassica rapa). Broccolini or "Tender Stem Broccoli" is a cross between broccoli and Chinese broccoli.
Broccoli is a cool-weather crop that does poorly in hot summer weather. Broccoli grows best when exposed to an average daily temperature between 18 and 23 °C (64 and 73 °F). When the cluster of flowers, also referred to as a "head" of broccoli, appear in the center of the plant, the cluster is green. Garden pruners or shears are used to cut the head about an inch from the tip. Broccoli should be harvested before the flowers on the head bloom bright yellow.
While the heading broccoli variety performs poorly in hot weather, mainly due to insects infestation, the sprouting variety is more resistant, though attention must be paid to sucking insects (such as aphids), caterpillars and whiteflies. Spraying of bacillus thuringiensis can control caterpillar attacks, while a citronella vase may ward off whiteflies.
Cauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. It is an annual plant that reproduces by seed. Typically, only the head (the white curd) is eaten. The cauliflower head is composed of a white inflorescence meristem. Cauliflower heads resemble those in broccoli, which differs in having flower buds.
For such a highly modified plant, cauliflower has a long history. François Pierre La Varenne employed chouxfleurs in Le cuisinier françois. They were introduced to France from Genoa in the 16th century, and are featured in Olivier de Serres' Théâtre de l'agriculture (1600), as cauli-fiori "as the Italians call it, which are still rather rare in France; they hold an honorable place in the garden because of their delicacy", but they did not commonly appear on grand tables until the time of Louis XIV.
There are four major groups of cauliflower.Italian Diverse in appearance, and biennial and annual in type, this group includes white, Romanesco, various green, purple, brown and yellow cultivars. This type is the ancestral form from which the others were derived. Northwest European biennial Used in Europe for winter and early spring harvest, this was developed in France in the 19th century, and includes the old cultivars Roscoff and Angers. Northern European annuals Used in Europe and North America for summer and fall harvest, it was developed in Germany in the 18th century, and includes the old cultivars Erfurt and Snowball. Asian A tropical cauliflower used in China and India, it was developed in India during the 19th century from the now-abandoned Cornish type, and includes old varieties Early Patna and Early Benaras. Varieties
There are hundreds of historic and current commercial varieties used around the world. A comprehensive list of about 80 North American varieties is maintained at North Carolina State University.Colours White White cauliflower is the most common colour of cauliflower. Orange Orange cauliflower (B. oleracea L. var. botrytis) contains 25% more vitamin A than white varieties. This trait came from a natural mutant found in a cauliflower field in Canada. Cultivars include 'Cheddar' and 'Orange Bouquet'. Green Green cauliflower, of the B. oleracea botrytis group, is sometimes called broccoflower. It is available both with the normal curd shape and a variant spiky curd called Romanesco broccoli. Both types have been commercially available in the U.S. and Europe since the early 1990s. Green-curded varieties include 'Alverda', 'Green Goddess' and 'Vorda'. Romanesco varieties include 'Minaret' and 'Veronica'. Purple The purple colour in this cauliflower is caused by the presence of the antioxidant group anthocyanins, which can also be found in red cabbage and red wine. Varieties include 'Graffiti' and 'Purple Cape'. In Great Britain and southern Italy, a broccoli with tiny flower buds is sold as a vegetable under the name "purple cauliflower". It is not the same as standard cauliflower with a purple curd.
- Sulforaphane, a compound released when cauliflower is chopped or chewed, may protect against cancer.
- Other glucosinolates
- Indole-3-carbinol, a chemical that enhances DNA repair, and acts as an estrogen antagonist, slowing the growth of cancer cells.
Boiling reduces the levels of these compounds, with losses of 20–30% after five minutes, 40–50% after ten minutes, and 75% after thirty minutes. However, other preparation methods, such as steaming, microwaving, and stir frying, have no significant effect on the compounds.
Cauliflower can be roasted, boiled, fried, steamed, or eaten raw. Steaming or microwaving better preserves anticancer compounds than boiling. When cooking, the outer leaves and thick stalks are removed, leaving only the florets. The leaves are also edible, but are most often discarded. The florets should be broken into similar-sized pieces so they are cooked evenly. After eight minutes of steaming, or five minutes of boiling, the florets should be soft, but not mushy (depending on size). Stirring while cooking can break the florets into smaller, uneven pieces.
The carrot (Daucus carota subsp. sativus; etymology: from Late Latin carōta, from Greek καρότον karōton, originally from the Indo-European root ker- (horn), due to its horn-like shape) is a root vegetable, usually orange in colour, though purple, red, white, and yellow varieties exist. It has a crisp texture when fresh. The most commonly eaten part of a carrot is a taproot, although the greens are sometimes eaten as well. It is a domesticated form of the wild carrot Daucus carota, native to Europe and southwestern Asia. The domestic carrot has been selectively bred for its greatly enlarged and more palatable, less woody-textured edible taproot. The Food and Agriculture Organization of the United Nations (FAO) reports that world production of carrots and turnips (these plants are combined by the FAO for reporting purposes) for calendar year 2011 was almost 35.658 million tonnes. Almost half were grown in China.
Soon after germination, carrot seedlings show a distinct demarcation between the taproot and the hypocotyl. The latter is thicker and lacks lateral roots. At the upper end of the hypocotyl is the seed leaf. The first true leaf appears about 10–15 days after germination. Subsequent leaves, produced from the stem nodes, are alternating (with a single leaf attached to a node, and the leaves growing in alternate directions) and compound, and arranged in a spiral. The leaf blades are pinnate. As the plant grows, the bases of the cotyledon are pushed apart. The stem, located just above the ground, is compressed and the internodes are not distinct. When the seed stalk elongates, the tip of the stem narrows and becomes pointed, extends upward, and becomes a highly branched inflorescence. The stems grow to 60–200 cm (20–80 in) tall.
Most of the taproot consists of parenchymatous outer cortex (phloem) and an inner core (xylem). High-quality carrots have a large proportion of cortex compared to core. Although a completely xylem-free carrot is not possible, some cultivars have small and deeply pigmented cores; the taproot can appear to lack a core when the colour of the cortex and core are similar in intensity. Taproots typically have a conical shape, although cylindrical and round cultivars are available. The root diameter can range from 1 cm (0.4 in) to as much as 10 cm (4 in) at the widest part. The root length ranges from 5 cm (2.0 in) to 50 cm (20 in), although most are between 10 and 25 cm (4 and 10 in).
Flower development begins when the flat apical meristem changes from producing leaves to an uplifted conical meristem capable of producing stem elongation and an inflorescence. The inflorescence is a compound umbel, and each umbel contains several umbellets. The first (primary) umbel occurs at the end of the main floral stem; smaller secondary umbels grow from the main branch, and these further branch into third, fourth, and even later-flowering umbels. A large primary umbel can contain up to 50 umbellets, each of which may have as many as 50 flowers; subsequent umbels have fewer flowers. Flowers are small and white, sometimes with a light green or yellow tint. They consist of five petals, five stamens, and an entire calyx. The anthers usually dehisce and the stamens fall off before the stigma becomes receptive to receive pollen. The anthers of the brown male sterile flowers degenerate and shrivel before anthesis. In the other type of male sterile flower, the stamens are replaced by petals, and these petals do not fall off. A nectar-containing disc is present on the upper surface of the carpels.
Flower development is protandrous, so the anthers release their pollen before the stigma of the same flower is receptive. The arrangement is centripetal, meaning the oldest flowers are near the edge and the youngest flowers are in the center. Flowers usually first open at the periphery of the primary umbel, followed about a week later on the secondary umbels, and then in subsequent weeks in higher-order umbels. The usual flowering period of individual umbels is 7 to 10 days, so a plant can be in the process of flowering for 30–50 days. The distinctive umbels and floral nectaries attract pollinating insects. After fertilization and as seeds develop, the outer umbellets of an umbel bend inward causing the umbel shape to change from slightly convex or fairly flat to concave, and when cupped it resembles a bird's nest.
The fruit that develops is a schizocarp consisting of two mericarps; each mericarp is an achene or true seed. The paired mericarps are easily separated when they are dry. Premature separation (shattering) before harvest is undesirable because it can result in seed loss. Mature seeds are flattened on the commissural side that faced the septum of the ovary. The flattened side has five longitudinal ribs. The bristly hairs that protrude from some ribs are usually removed by abrasion during milling and cleaning. Seeds also contain oil ducts and canals. Seeds vary somewhat in size, ranging from less than 500 to more than 1000 seeds per gram.
The carrot is a diploid species, and has nine relatively short, uniform-length chromosomes (2n=9). The genome size is estimated to be 473 mega base pairs, which is four times larger than Arabidopsis thaliana, one-fifth the size of the maize genome, and about the same size as the rice genome.
The wild ancestors of the carrot are likely to have come from Iran and Afghanistan, which remain the centre of diversity of Daucus carota, the wild carrot. Selective breeding over the centuries of a naturally occurring subspecies of the wild carrot, Daucus carota subsp. sativus, to reduce bitterness, increase sweetness and minimise the woody core, has produced the familiar garden vegetable.
In early use, carrots were grown for their aromatic leaves and seeds, not their roots. Carrot seeds have been found in Switzerland and Southern Germany dating to 2000–3000 BC. Some relatives of the carrot are still grown for their leaves and seeds, such as parsley, fennel, dill and cumin. The first mention of the root in classical sources is in the 1st century. The modern carrot originated in Afghanistan about 1100 years ago. It appears to have been introduced to Europe via Spain by the Moors in the 8th century. The 12th-century Arab Andalusian agriculturist, Ibn al-'Awwam, describes both red and yellow carrots;Simeon Seth also mentions both colours in the 11th century. Cultivated carrots appeared in China in the 14th century, and in Japan in the 18th century. Orange-coloured carrots appeared in the Netherlands in the 17th century. These, the modern carrots, were intended by the antiquary John Aubrey (1626–1697) when he noted in his memoranda "Carrots were first sown at Beckington in Somersetshire Some very old Man there [in 1668] did remember their first bringing hither." European settlers introduced the carrot to the United States in the 17th century.
Polyacetylenes can be found in Apiaceae vegetables like carrots where they show cytotoxic activities.Falcarinol and falcarindiol (cis-heptadeca-1,9-diene-4,6-diyne-3,8-diol) are such compounds. This latter compound shows antifungal activity towards Mycocentrospora acerina and Cladosporium cladosporioides. Falcarindiol is the main compound responsible for bitterness in carrots.
Other compounds such as pyrrolidine (present in the leaves),6-hydroxymellein,6-methoxymellein, eugenin, 2,4,5-trimethoxybenzaldehyde (gazarin) or (Z)-3-acetoxy-heptadeca-1,9-diene-4,6-diin-8-ol (falcarindiol 3-acetate) can also be found in carrot.
Most carrot cultivars are about 88% water, 7% sugar, 1% protein, 1% fibre, 1% ash, and 0.2% fat. The fibre comprises mostly cellulose, with smaller proportions of hemicellulose and lignin. Carrots contain almost no starch.Free sugars in carrot include sucrose, glucose, xylose and fructose. Nitrite and nitrate contents are about 40 and 0.41 milligrams per 100 grams (fresh), respectively. Most of the taste of the vegetable is due to glutamic acid and other free amino acids. Other acids present in trace amounts include succinic acid, α-ketoglutaric acid, lactic acid and glycolic acid; the major phenolic acid is caffeic acid.
The carrot gets its characteristic and bright orange colour from β-carotene, and lesser amounts of α-carotene and γ-carotene. α and β-carotenes are partly metabolised into vitamin A in humans. β-carotene is the predominant carotenoid, although there are lesser amounts of α-carotene and γ-carotene. There are typically between 6000 and 54,000 micrograms of carotenoids per 100 grams of carrot root. Carrot extracts are used by poultry producers to improve animal skin and alter the colour of egg yolk. Massive overconsumption of carrots can cause carotenosis, a benign condition in which the skin turns orange. Carrots are also rich in antioxidants and minerals.Ethnomedically, the roots are used to as an emmenagogue (to increase blood flow in the pelvic area and uterus), a carminative (to reduce flatulence), to treat digestive problems, intestinal parasites, and tonsillitis or constipation.
Lack of vitamin A can cause poor vision, including night vision, and these can be restored by adding vitamin A to the diet. An urban legend states that eating large quantities of carrots will allow one to see in the dark. This myth developed from stories about British gunners in World War II, who were able to shoot down German planes at night. The rumour arose during the Battle of Britain when the RAF circulated a story about their pilots' carrot consumption in an attempt to cover up the discovery and effective use of radar technologies in engaging enemy planes, as well as the use of red light (which does not destroy night vision) in aircraft instruments. It reinforced existing German beliefs, and helped to encourage Britons who were trying to improve their night vision during the blackout to grow and eat the vegetable, which was not rationed like most other foodstuffs. A "Dr. Carrot" advertising campaign encouraged its consumption.
Carrots can be eaten in a variety of ways. Only 3% of the β-carotene in raw carrots is released during digestion: this can be improved to 39% by pulping, cooking and adding cooking oil. Alternatively they may be chopped and boiled, fried or steamed, and cooked in soups and stews, as well as baby and pet foods. A well-known dish is carrots julienne. Together with onion and celery, carrots are one of the primary vegetables used in a mirepoix to make various broths.
The greens are edible as a leaf vegetable, but are only occasionally eaten by humans; some sources suggest that the greens contain toxic alkaloids. When used for this purpose, they are harvested young in high-density plantings, before significant root development, and typically used stir-fried, or in salads. Some people are allergic to carrots. In a 2010 study on the prevalence of food allergies in Europe, 3.6 percent of young adults showed some degree of sensitivity to carrots. Because the major carrot allergen, the protein Dauc c 1.0104, is cross-reactive with homologues in birch pollen (Bet v 1) and mugwort pollen (Art v 1), most carrot allergy sufferers are also allergic to pollen from these plants.
In India carrots are used in a variety of ways, as salads or as vegetables added to spicy rice or daal dishes. A popular variation in north India is the Gajar Ka Halwa carrot dessert, which has carrots grated and cooked in milk until the whole mixture is solid, after which nuts and butter are added. Carrot salads are usually made with grated carrots in western parts with a seasoning of mustard seeds and green chillies popped in hot oil, while adding carrots to rice usually is in julienne shape.
The variety of carrot found in north India is rare everywhere except in Central Asia and other contiguous regions, and is now growing in popularity in larger cosmopolitan cities in South India. The north Indian carrot is pink-red comparable to plum or raspberry or deep red apple in colour (without a touch of yellow or blue) while most other carrot varieties in the world vary from orange to yellow in colour, comparable to hallowe'en pumpkins.
Since the late 1980s, baby carrots or mini-carrots (carrots that have been peeled and cut into uniform cylinders) have been a popular ready-to-eat snack food available in many supermarkets. Carrots are puréed and used as baby food, dehydrated to make chips, flakes, and powder, and thinly sliced and deep-fried, like potato chips.
The sweetness of carrots allows the vegetable to be used in some fruit-like roles. Grated carrots are used in carrot cakes, as well as carrot puddings, an old English dish thought to have originated in the early 19th century. Carrots can also be used alone or with fruits in jam and preserves. Carrot juice is also widely marketed, especially as a health drink, either stand-alone or blended with fruits and other vegetables.
Carrots are useful companion plants for gardeners. There is experimental evidence that growing it intercropped with tomatoes increases tomato production. If left to flower, it (like any umbellifer) attracts predatory wasps that kill many garden pests.
Carrots grow best in full sun but tolerate some shade. The optimum growth temperature is between 16 and 21 °C (61 and 70 °F). In order to avoid growing deformed carrots it is better to plant them in loose soil free from rocks. They thrive in raised garden beds. High nitrogen levels should be avoided, as this will cause the vegetables to become hairy and misshapen. The seeds, which are 1–3 mm in diameter, should be sown about 2 cm deep. Carrots take around four months to mature and it is suggested that carrot seeds are sown from mid-February to July.
There are several diseases that can reduce the yield and market market of carrots. The most devastating carrot disease is Alternaria leaf blight, which has been known to eradicate entire crops. A bacterial leaf blight caused by Xanthomonas campestris can also be destructive in warm, humid areas. Root knot nematodes (Meloidogyne species) can cause stubby or forked roots, or galls. Cavity spot, caused by the oomycetes Pythium violae and Pythium sulcatum, results in irregularly shaped, depressed lesions on the taproots.
Physical damage can also reduce the value of carrot crops. The two main forms of damage are splitting, whereby a longitudinal crack develops during growth that can be a few centimetres to the entire length of the root, and breaking, which occurs postharvest. These disorders can affect over 30% of commercial crops. Factors associated with high levels of splitting include wide plant spacing, early sowing, lengthy growth durations, and genotype.
Carrot cultivars can be grouped into two broad classes, eastern carrots and western carrots. More recently, a number of novelty cultivars have been bred for particular characteristics.
Eastern carrots were domesticated in Central Asia, probably in modern-day Iran and Afghanistan in the 10th century, or possibly earlier. Specimens of the eastern carrot that survive to the present day are commonly purple or yellow, and often have branched roots. The purple colour common in these carrots comes from anthocyanin pigments.
The western carrot emerged in the Netherlands in the 17th century, its orange colour making it popular in those countries as an emblem of the House of Orange and the struggle for Dutch independence. The orange colour results from abundant carotenes in these cultivars.
Western carrot cultivars are commonly classified by their root shape:
- Chantenay carrots are shorter than other cultivars, but have greater girth, sometimes growing up to 8 centimetres (3 in) in diameter. They have broad shoulders and taper towards a blunt, rounded tip. They are most commonly diced for use in canned or prepared foods.
- Danvers carrots have a conical shape, having well-defined shoulders and tapering to a point at the tip. They are somewhat shorter than Imperator cultivars, but more tolerant of heavy soil. Danvers cultivars are often puréed as baby food. They were developed in 1871 in Danvers, Massachusetts.
One particular variety lacks the usual orange pigment from carotenes, owing its white colour to a recessive gene for tocopherol (vitamin E). Derived from Daucus carota L. and patented at the University of Wisconsin–Madison, the variety is intended to supplement the dietary intake of Vitamin E.
Carrot is one of the top-ten most economically important vegetables crops in the world. In 2011, according to the Food and Agriculture Organization of the United Nations, 35.658 million tonnes of carrots and turnips were produced worldwide for human consumption, grown on 1,184,000 hectares (2,926,000 acres). With 16.233 million tonnes, China was by far the largest producer and accounted for 45.5% of the global output, followed by Russia (1.735 million tonnes), the United States (1.342), Uzbekistan (1.222), Poland (0.887), Ukraine (0.864), and the United Kingdom (0.694). About 61% of world carrot production occurred in Asia, followed by the Europe (24.2%) and the Americas (North, Central, and South America and the Caribbean) (9.7%). Less than 4% of the world's 2011 total was produced in Africa. Global production has increased from 21.4 million tonnes in 2000, 13.7 million tonnes in 1990, 10.4 million tonnes in 1980, and 7.85 million tonnes in 1970. The rate of increase in the global production of carrots has been greater than the world's population growth rate, and greater than the overall increase in world vegetable production. Europe was traditionally the major centre of production, but was overtaken by Asia in 1997. The growth in global production is largely the result of increases in production area, rather than average yield. Modest improvements in the latter can be attributed to optimised agricultural practices, the development of better cultivars (including hybrids), and increased farm mechanisation.
Carrots can be stored for several months in the refrigerator or over winter in a moist, cool place. For long term storage, unwashed carrots can be placed in a bucket between layers of sand, a 50/50 mix of sand and wood shavings, or in soil. A temperature range of 32 to 40°F (0 to 5°C) is best.
The turnip or white turnip (Brassica rapa subsp. rapa) is a root vegetable commonly grown in temperate climates worldwide for its white, bulbous taproot. Small, tender varieties are grown for human consumption, while larger varieties are grown as feed for livestock.
In the north of England and Scotland, the turnip is called neep; the word turnip itself is an old compound of neep. Neep often also refers to the larger, yellow rutabaga root vegetable which is also known as the "swede" (from "Swedish turnip").
The most common type of turnip is mostly white-skinned apart from the upper 1–6 centimeters, which protrude above the ground and are purple, red, or greenish wherever sunlight has fallen. This above-ground part develops from stem tissue, but is fused with the root. The interior flesh is entirely white. The entire root is roughly conical, but can be occasionally global, about 5–20 centimeters in diameter, and lacks side roots. The taproot (the normal root below the swollen storage root) is thin and 10 centimeters or more in length; it is trimmed off before marketing. The leaves grow directly from the above-ground shoulder of the root, with little or no visible crown or neck (as found in rutabagas).
Turnip leaves are sometimes eaten as "turnip greens" ("turnip tops" in the UK), and they resemble mustard greens in flavor. Turnip greens are a common side dish in southeastern US cooking, primarily during late fall and winter. Smaller leaves are preferred; however, any bitter taste of larger leaves can be reduced by pouring off the water from initial boiling and replacing it with fresh water. Varieties specifically grown for the leaves resemble mustard greens more than those grown for the roots, with small or no storage roots. Varieties of B. rapa that have been developed only for the use of leaves are called Chinese cabbage. Both leaves and root have a pungent flavor similar to raw cabbage or radishes that becomes mild after cooking.
Turnip roots weigh up to about one kilogram, although they can be harvested when smaller. Size is partly a function of variety and partly a function of the length of time the turnip has grown. Most very small turnips (also called baby turnips) are specialty varieties. These are only available when freshly harvested and do not keep well. Most baby turnips can be eaten whole, including their leaves. Baby turnips come in yellow-, orange-, and red-fleshed varieties as well as white-fleshed. Their flavor is mild, so they can be eaten raw in salads like radishes and other vegetables.
The turnip's root is high in vitamin C. The green leaves of the turnip top ("turnip greens") are a good source of vitamin A, folate, vitamin C, vitamin K and calcium. Turnip greens are high in lutein (8.5 mg / 100 g).
One medium raw turnip (122 g) contains the following nutritional information according to the USDA:
- Calories : 34
- Fat: 0.12
- Carbohydrates: 7.84
- Fibers: 2.2
- Protein: 1.10
- Cholesterol: 0
Like rutabaga, turnip contains bitter cyanoglucosides that release small amounts of cyanide. Sensitivity to the bitterness of these cyanoglucosides is controlled by a paired gene. Subjects who have inherited two copies of the "sensitive" gene find turnips twice as bitter as those who have two "insensitive" genes, and thus may find turnips and other cyanoglucoside-containing foods intolerably bitter.
There is evidence that the turnip was domesticated before the 15th century BC; it was grown in India at this time for its oil-bearing seeds. The turnip was a well-established crop in Hellenistic and Roman times, which leads to the assumption that it was brought into cultivation earlier. Sappho, a Greek poet from the 7th century BC, calls one of her paramours Gongýla, "turnip". Zohary and Hopf note, however, "there are almost no archaeological records available" to help determine its earlier history and domestication. Wild forms of the hot turnip and its relatives the mustards and radishes are found over west Asia and Europe, suggesting their domestication took place somewhere in that area. However Zohary and Hopf conclude, "Suggestions as to the origins of these plants are necessarily based on linguistic considerations."
The 1881 Household Cyclopedia gives these instructions for field cultivation of turnips:
The benefits derived from turnip husbandry are of great magnitude; light soils are cultivated with profit and facility; abundance of food is provided for man and beast; the earth is turned to the uses for which it is physically calculated, and by being suitably cleaned with this preparatory crop, a bed is provided for grass seeds, wherein they flourish and prosper with greater vigor than after any other preparation.
The first ploughing is given immediately after harvest, or as soon as the wheat seed is finished, either in length or across the field, as circumstances may seem to require. In this state the ground remains till the oat seed is finished, when a second ploughing is given to it, usually in a contrary direction to the first. It is then repeatedly harrowed, often rolled between the harrowings and every particle of root-weeds carefully picked off with the hand; a third ploughing is then bestowed, and the other operations are repeated. In this stage, if the ground has not been very foul, the seed process.
The next part of the process is the sowing of the seed; this may be performed by drilling machines of different sizes and constructions, through all acting on the same principle. A machine drawn by a horse in a pair of shafts, sows two drills at a time and answers extremely well, where the ground is flat, and the drills properly made up. The weight of the machine ensures a regularity of sowing hardly to be gained by those of a different size and construction. From two to three pounds of seed are sown upon the acre (2 to 3 kg/hectare), though the smallest of these quantities will give many more plants in ordinary seasons than are necessary; but as the seed is not an expensive article the greater part of farmers incline to sow thick, which both provides against the danger of part of the seed perishing, and gives the young plants an advantage at the outset.
Turnips are sown from the beginning to the end of June, but the second and third weeks of the month are, by judicious farmers, accounted the most proper time. Some people have sown as early as May, and with advantage, but these early fields are apt to run to seed before winter, especially if the autumn be favorable to vegetation. As a general rule it may be laid down that the earliest sowings should be on the latest soils; plants on such soils are often long before they make any great progress, and, in the end, may be far behind those in other situations, which were much later sown. The hot turnip plant, indeed, does not thrive rapidly till its roots reach the dung, and the previous nourishment afforded them is often so scanty as to stunt them altogether before they get so far.
The first thing to be done in this process is to run a horse-hoe, called a scraper, along the intervals, keeping at such a distance from the young plants that they shall not be injured; this operation destroys all the annual weeds which have sprung up, and leaves the plants standing in regular stripes or rows. The hand hoeing then commences, by which the turnips are all singled out at a distance of from 8–12 inches, and the redundant ones drawn into the spaces between the rows. The singling out of the young plants is an operation of great importance, for an error committed in this process can hardly be afterward rectified. Boys and girls are always employed as hoers; but a steady and trusty man-servant is usually set over them to see that the work is properly executed.
In eight or ten days, or such a length of time as circumstances may require, a horse-hoe of a different construction from the scraper is used. This, in fact, is generally a small plough, of the same kind with that commonly wrought, but of smaller dimensions. By this implement, the earth is pared away from the sides of the drills, and a sort of new ridge formed in the middle of the former interval. The hand-hoers are again set to work, and every weed and superfluous turnip is cut up; afterward the horse-hoe is employed to separate the earth, which it formerly threw into the furrows, and lay it back to the sides of the drills. On dry lands this is done by the scraper, but where the least tendency to moisture prevails, the small plough is used, in order that the furrows may be perfectly cleaned out. This latter mode, indeed, is very generally practiced.
As a root crop, turnips grow best in cool weather; hot temperatures cause the roots to become woody and bad-tasting. They are typically planted in the spring in cold-weather climates (such as the northern US and Canada) where the growing season is only 3–4 months. In temperate climates (ones with a growing season of 5–6 months), turnips may also be planted in late summer for a second fall crop. In warm-weather climates (7 or more month growing season), they are planted in the fall. 55–60 days is the average time from planting to harvest.
Turnips are a biennial plant, taking two years from germination to reproduction. The root spends the first year growing and storing nutrients, and the second year flowers, produces seeds, and dies. The flowers of the turnip are tall and yellow, with the seeds forming in pea-like pods. In areas with less than 7 month growing seasons, temperatures are too cold for the roots to survive the winter months. In order to produce seeds, it's necessary to pull the turnip and store it overwinter, taking care not to damage the leaves. During the spring, it may be set back in the ground to complete its life cycle.
Pliny the Elder considered the turnip one of the most important vegetables of his day, rating it "directly after cereals or at all events after the bean, since its utility surpasses that of any other plant". Pliny praised it as a source of fodder for farm animals, noting that this vegetable is not particular about the type of soil it grows in and that - because it can be left in the ground until the next harvest - it "prevents the effects of famine" for humans (N.H. 18.34).
In the south of England and Scotland, the smaller white vegetable is often called neeps or turnips, while it is the larger rutabagas which are referred to as swedes. Turnips or neeps are mashed and eaten with haggis, traditionally on Burns Night.
Turnip lanterns are an old tradition; since inaugural Halloween festivals in Ireland and Scotland, turnips (rutabaga) have been carved out and used as candle lanterns. At Samhain, candle lanterns carved from turnips — samhnag — were part of the traditional Celtic festival. Large turnips were hollowed out, carved with faces and placed in windows, used to ward off harmful spirits. At Halloween in Scotland in 1895, masqueraders in disguise carried lanterns made out of scooped out turnips.
In Nordic countries turnips provided the staple crop before their replacement by the potato in the 18th century. The cross between turnip and cabbage, rutabaga, was possibly first produced in Scandinavia.
In Turkey, particularly in the area near Adana, turnips are used to flavor şaljam, a juice made from purple carrots and spices served ice cold. In Middle Eastern countries such as Lebanon, turnips are pickled.
In the Southern United States, stewed turnips are eaten as a root vegetable in the autumn and winter. The greens of the turnip are harvested and eaten all year. Turnip greens may be cooked with a ham hock or piece of fat pork meat, the juice produced in the stewing process prized as pot liquor. Stewed turnip greens are often eaten with vinegar.
In Iran, boiled turnip-roots (with salt) are a common household remedy for cough and cold.
In the Punjab and Kashmir regions of India and Pakistan turnips are used in variety of dishes, most notably shab-daig.
The low popularity of turnips (nabos) in Brazil, traditionally regarded as distasteful, or at least somewhat disagreeable and unpleasant to the first bite, and that – to the popular knowledge – only feature significantly in the country's Japanese cuisine (as daikon – actually a big and white variety of radish, vegetable there known as rabanete), is often a source of humor. Part of this bias reportedly stems from the Middle Ages, where, for the reason of being inexpensive, turnips became [in Iberia and thus in Iberian-descended cultures] associated with the poor, and avoided in the diet of the nobility.