A bean is the seed of several plants in the family Fabaceae, which are used as vegetables for human or animal food.[1] They can be cooked in many different ways,[2] including boiling, frying, and baking, and are used in many traditional dishes throughout the world.
The word "bean" and its Germanic cognates (e.g. German Bohne) have existed in common use in West Germanic languages since before the 12th century, referring to broad beans, chickpeas, and other pod-borne seeds. This was long before the New World genus Phaseolus was known in Europe. With the Columbian exchange of domestic plants between Europe and the Americas, use of the word was extended to pod-borne seeds of Phaseolus, such as the common bean and the runner bean, and the related genus Vigna. The term has long been applied generally to many other seeds of similar form, such as Old World soybeans, peas, other vetches, and lupins, and even to those with slighter resemblances, such as coffee beans, vanilla beans, castor beans, and cocoa beans. Thus the term "bean" in general usage can refer to a host of different species.[3]
Seeds called "beans" are often included among the crops called "pulses" (legumes), although the words are not always interchangeable (usage varies by plant variety and by region). Both terms, beans and pulses, are usually reserved for grain crops and thus exclude those legumes that have tiny seeds and are used exclusively for non-grain purposes (forage, hay, and silage), such as clover and alfalfa. The United Nations Food and Agriculture Organization defines "BEANS, DRY" (item code 176)[3] as applicable only to species of Phaseolus. This is one of various examples of how narrower word senses enforced in trade regulations or botany often coexist in natural language with broader senses in culinary use and general use; other common examples are the narrow sense of the word nut and the broader sense of the word nut, and the fact that tomatoes are fruit, botanically speaking, but are often treated as vegetables in culinary and general usage. Relatedly, another detail of usage is that several species of plants that are sometimes called beans, including Vigna angularis (azuki bean), mungo (black gram), radiata (green gram), and aconitifolia (moth bean), were once classified as Phaseolus but later reclassified—but the taxonomic revision does not entirely stop the use of well-established senses in general usage.
Unlike the closely related pea, beans are a summer crop that needs warm temperatures to grow. Legumes are capable of nitrogen fixation and hence need less fertiliser than most plants. Maturity is typically 55–60 days from planting to harvest.[4] As the bean pods mature, they turn yellow and dry up, and the beans inside change from green to their mature colour that they have when fully ripe. Many beans are vines, as such the plants need external support, which may take the form of special "bean cages" or poles. Native Americans customarily grew them along with corn and squash (the so-called Three Sisters),[5] with the tall cornstalks acting as support for the beans.
In more recent times, the so-called "bush bean" has been developed which does not require support and has all its pods develop simultaneously (as opposed to pole beans which develop gradually).[6] This makes the bush bean more practical for commercial production.
Beans were an important source of protein throughout Old and New World history, and still are today.
Beans are one of the longest-cultivated plants in history. Broad beans, also called fava beans, are in their wild state the size of a small fingernail, and were first gathered in Afghanistan and the Himalayan foothills.[7] An early cultivated form were grown in Thailand from the early seventh millennium BCE, predating ceramics.[8] Beans were deposited with the dead in ancient Egypt. Not until the second millennium BCE did cultivated, large-seeded broad beans appear in the Aegean region, Iberia, and transalpine Europe.[9] In the Iliad (8th century BCE), there is a passing mention of beans and chickpeas cast on the threshing floor.[10]
The oldest-known domesticated beans in the Americas were found in Guitarrero Cave, an archaeological site in Peru, and dated to around the second millennium BCE. Genetic analyses of the common bean Phaseolus show that it originated in Mesoamerica, and subsequently spread southward, along with maize and squash, traditional companion crops.[11]
Most of the kinds of beans commonly eaten today are part of the genus Phaseolus, which originated in the Americas. The first European to encounter them was Christopher Columbus, while exploring what may have been the Bahamas, and saw them growing in fields. Five kinds of Phaseolus beans were domesticated[12] by pre-Columbian peoples: common beans (P. vulgaris) grown from Chile to the northern part of what is now the United States; and lima and sieva beans (P. lunatus); as well as the less widely distributed teparies (P. acutifolius), scarlet runner beans (P. coccineus), and polyanthus beans.[13]
One well-documented use of beans by pre-Columbian people as far north as the Atlantic seaboard is the "Three Sisters" method of companion plant cultivation: Many tribes would grow beans together with maize or "corn", and squash. The corn would not be planted in rows as is done by European agriculture, but in a checkerboard/hex fashion across a field, in separate patches of one to six stalks each.Beans would be planted around the base of the developing stalks, and would vine their way up as the stalks grew. All American beans at that time were vine plants; "bush beans" were cultivated more recently. The cornstalks would work as a trellis for the bean plants, and the beans would provide much-needed nitrogen for the corn. Squash would be planted in the spaces between the patches of corn in the field. They would be provided slight shelter from the sun by the corn, would shade the soil and reduce evaporation, and would deter many animals from attacking the corn and beans because their coarse, hairy vines and broad, stiff leaves are difficult or uncomfortable for animals such as deer and raccoons to walk through, crows to land on, and are a deterrent to other animals as well.
Beans were cultivated across Chile in Pre-Hispanic times, likely as far south as Chiloé Archipelago.[14]
Dry beans come from both Old World varieties of broad beans (fava beans) and New World varieties (kidney, black, cranberry, pinto, navy/haricot).
Most of the foods we call "beans", "legumes", "lentils" and "pulses" belong to the same family, Fabaceae ("leguminous" plants), but are from different genera and species, native to different homelands and distributed worldwide depending on their adaptability.[15] Many varieties are eaten both fresh (the whole pod, and the immature beans may or may not be inside) or shelled (immature seeds, mature and fresh seeds, or mature and dried seeds). Numerous legumes look similar, and have become naturalized in locations across the world, which often lead to similar names for different species.
| Phaseolus | P. vulgaris Kidney Bean, Pinto Bean, Navy Bean (Cannellini, Haricot Beans/French Beans/Pole Beans/Bush Beans), Black Beans, Borlotti Beans Lima Beans Runner Beans, Flat Beans Tepary Bean | The Americas | Tropical, Subtropical, Warm Temperate | Certain varieties contain high levels of toxic phytohemagglutinin. Requires soaking and then cooking at or above 100C for a minimum of 30 minutes, and ideally much longer.[16] [17] [18] | |
| Pisum | Mediterranean | Subtropical, Temperate, Occasionally Cool Tropical | |||
| Vigna | V. radiata Mung Bean Urad Yardlong bean, Black-eyed Peas Moth bean Adzuki beans | Mostly South Asia | Equatorial, Pantropical, Warm Subtropical, Hot Temperate | ||
| Cajanus | C. cajan Pigeon Pea | Indian Subcontinent | Pantropical, Equatorial | ||
| Lens | L. culinaris (Lentils): Red Lentil, Green Lentil, Puy Lentil | Near East/Levant | Temperate, Subtropical, Cool Tropical | ||
| Cicer | C. arietinum Chickpeas (Garbanzo Beans) | Turkey/Levant/Near East | Temperate, Subtropical, Cool Tropical | ||
| Vicia | V. faba Fava Beans (Broad Beans) Bitter vetch V. sativa: Common vetch | Near East | Subtropical, Temperate | Causes Favism in those susceptible.[19] [20] | |
| Arachis | A. hypogaea Peanut (Groundnut) | South America | Warm Subtropical, Cool Tropical | ||
| Glycine | G. max Soybean | East Asia | Hot Temperate, Subtropical, Cool Tropical | ||
| Macrotyloma | M. uniflorum Horsegram | South Asia | Tropical, Subtropical | ||
| Mucuna | M. pruriens Velvet Bean | Tropical Asia and Africa | Tropical, Warm Subtropical | Contains L-DOPA,[21] and smaller amounts of other psychoactive compounds. Can also cause itching and rashes on contact. | |
| Lupinus | L. albus White LupinL. mutabilis Tarwi/Andean Lupin | The Mediterranean, Balkans, Levant (albinus), The Andes (mutabilis) | Subtropical, Temperate | Requires prolonged soaking in the correct way to reduce toxic compounds.[22] | |
| Ceratonia | C. siliqua Carob bean | Mediterranean, Middle East | Subtropical, Arid Subtropical, Hot Temperate | ||
| Canavalia | C. gladiata: Sword Bean
Jack Beans | South Asia or Africa (C. gladiata), Brazil and South America (C. Ensiformis) | Tropical | ||
| Cyamopsis | C. tetragonoloba Guar Bean | Africa or South Asia | Tropical, Semi-Arid | Source of Guar gum | |
| Lablab | L. purpureus Hyacinth Bean/Lablab Bean | South Asia, Indian Subcontinent or Africa | Tropical | ||
| Psophocarpus | P. tetranoglobulus Winged Bean | New Guinea | Tropical, Equatorial | ||
| Clitoria | C. ternatea Butterfly Pea | Equatorial and Tropical Asia | Tropical, Subtropical | Flowers used as a natural food colouring | |
| Lathyrus | L. sativus Grass PeaL. tuberosus Tuberous Pea | Balkans, India or Asia | Subtropical | Can cause Lathyrism if used as staple.[23] [24] | |
| Trifolium | T. repens White Clover Red Clover | Europe and Central Asia | Subtropical, Temperate | ||
| Medicago | M. sativa Alfalfa | Central Asia | Subtropical, Temperate | ||
| Melilotus | M. officinalis Sweet Clover | Europe and Central Asia | Subtropical, Temperate | Contains Coumarins, an important class of perfume ingredients. Coumarin is also a blood thinner. | |
| Tamarindus | T. indica Tamarind | Africa | Tropical, Subtropical |
As of 2023, the Norwegian Svalbard Global Seed Vault holds more than 40,000 accessions of Phaseolus bean species.[25]
Raw green beans are 90% water, 7% carbohydrates, 2% protein, and contain negligible fat (table). In a 100g reference serving, raw green beans supply 31 calories of food energy, and are a moderate source (10-19% of the Daily Value, DV) of vitamin C (15% DV) and vitamin B6 (11% DV), with no other micronutrients in significant content (table).
Many types of bean like kidney bean contain significant amounts of antinutrients that inhibit some enzyme processes in the body. Phytic acid and phytates, present in grains, nuts, seeds and beans, interfere with bone growth and interrupt vitamin D metabolism. Pioneering work on the effect of phytic acid was done by Edward Mellanby from 1939.[26] [27]
See main article: Phytohaemagglutinin and Soybean agglutinin. Some kinds of raw beans contain a harmful, tasteless toxin: the lectin phytohaemagglutinin, which must be removed by cooking. Red kidney beans are particularly toxic, but other types also pose risks of food poisoning. Even small quantities (4 or 5 raw beans) may cause severe stomachache, vomiting, and diarrhea. This risk does not apply to canned beans because they have already been cooked.[28] A recommended method is to boil the beans for at least ten minutes; under-cooked beans may be more toxic than raw beans.[29]
Cooking beans, without bringing them to a boil, in a slow cooker at a temperature well below boiling may not destroy toxins. A case of poisoning by butter beans used to make falafel was reported; the beans were used instead of traditional broad beans or chickpeas, soaked and ground without boiling, made into patties, and shallow fried.[30]
Bean poisoning is not well known in the medical community, and many cases may be misdiagnosed or never reported; figures appear not to be available. In the case of the UK National Poisons Information Service, available only to health professionals, the dangers of beans other than red beans were not flagged .[30]
Fermentation is used in some parts of Africa to improve the nutritional value of beans by removing toxins. Inexpensive fermentation improves the nutritional impact of flour from dry beans and improves digestibility, according to research co-authored by Emire Shimelis, from the Food Engineering Program at Addis Ababa University.[31] Beans are a major source of dietary protein in Kenya, Malawi, Tanzania, Uganda and Zambia.[32]
It is common to make beansprouts by letting some types of bean, often mung beans, germinate in moist and warm conditions; beansprouts may be used as ingredients in cooked dishes, or eaten raw or lightly cooked. There have been many outbreaks of disease from bacterial contamination, often by salmonella, listeria, and Escherichia coli, of beansprouts not thoroughly cooked,[33] some causing significant mortality.[34]
Many edible beans, including broad beans, navy beans, kidney beans and soybeans, contain oligosaccharides (particularly raffinose and stachyose), a type of sugar molecule also found in cabbage. An anti-oligosaccharide enzyme is necessary to properly digest these sugar molecules. As a normal human digestive tract does not contain any anti-oligosaccharide enzymes, consumed oligosaccharides are typically digested by bacteria in the large intestine. This digestion process produces gases, such as methane as a byproduct, which are then released as flatulence.[35] [36] [37] [38]
The production data for legumes are published by FAO in three categories:
The following is a summary of FAO data.[39]
| Total pulses (dry) [1726] | 40.78 | 41.63 | 56.23 | 77.57 | 81.80 | 2.01 | Per capita production had decreased. (Population increase was 2.4×) | |
| Oil crops (dry) | ||||||||
|---|---|---|---|---|---|---|---|---|
| Soybeans [236] | 26.88 | 88.53 | 177.02 | 323.20 | 334.89 | 12.46 | Drastic increase driven by the demand for animal feeds and oil. | |
| Groundnuts, with shell [242] | 14.13 | 20.58 | 35.82 | 45.08 | 43.98 | 3.11 | ||
| Fresh vegetables (80–90% water) | ||||||||
| Beans, green [414] | 2.63 | 4.09 | 10.92 | 23.12 | 23.60 | 8.96 | ||
| Peas, green [417] | 3.79 | 5.66 | 12.41 | 19.44 | 19.88 | 5.25 | ||
Main crops of "Pulses, Total (dry)" are "Beans, dry [176]" 26.83 million tons, "Peas, dry [187]" 14.36 million tons, "Chick peas [191]" 12.09 million tons, "Cow peas [195]" 6.99 million tons, "Lentils [201]" 6.32 million tons, "Pigeon peas [197]" 4.49 million tons, "Broad beans, horse beans [181]" 4.46 million tons. In general, the consumption of pulses per capita has been decreasing since 1961. Exceptions are lentils and cowpeas.
| Country | 2016 | Share | Remarks | ||
|---|---|---|---|---|---|
| Total | 81.80 | 100% | |||
| 1 | India | 17.56 | 21.47% | ||
| 2 | Canada | 8.20 | 10.03% | ||
| 3 | Myanmar | 6.57 | 8.03% | ||
| 4 | China | 4.23 | 5.17% | ||
| 5 | Nigeria | 3.09 | 3.78% | ||
| 6 | Russia | 2.94 | 3.60% | ||
| 7 | Ethiopia | 2.73 | 3.34% | ||
| 8 | Brazil | 2.62 | 3.21% | ||
| 9 | Australia | 2.52 | 3.09% | ||
| 10 | USA | 2.44 | 2.98% | ||
| 11 | Niger | 2.06 | 2.51% | ||
| 12 | Tanzania | 2.00 | 2.45% | ||
| Others | 24.82 | 30.34% |
The world leader in production of dry beans (Phaseolus spp),[42] is India, followed by Myanmar (Burma) and Brazil. In Africa, the most important producer is Tanzania.[43]
| Country | Production (tonnes) | Footnote | |
|---|---|---|---|
| 5,460,000 | F | ||
| 3,053,012 | |||
| 3,035,290 | A | ||
| 1,495,180 | |||
| 1,281,586 | |||
| 1,267,648 | F | ||
| 1,056,071 | |||
| 774,366 | F | ||
| 633,823 | |||
| 603,980 | |||
| World | 27,545,942 | A |
Source: UN Food and Agriculture Organization (FAO)[44]