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For other uses, see Bean (disambiguation).

French bean pods on a plant

A bean is the seed of any plant in the legume family (Fabaceae) used as a vegetable for human consumption or animal feed.[1] The seeds are often preserved through drying, but fresh beans are also sold. Most beans are traditionally soaked and boiled, but they can be cooked in many different ways,[2] including frying and baking, and are used in many traditional dishes throughout the world. The unripe seedpods of some varieties are also eaten whole as green beans or edamame (immature soybean), but fully ripened beans contain toxins like phytohemagglutinin and require cooking.

Terminology

The word 'bean', for the Old World vegetable, existed in Old English,[3] 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 eeds of similar form,[4][5] such as Old World soybeans and lupins, and to unrelated plants with large seeds or pods, such as coffee beans, vanilla beans, castor beans, and cocoa beans.[6]

Seeds called 'beans' are often included among the 'pulses' (legumes),[4] although the words are not always interchangeable. Both 'beans' and 'pulses' usually denote grain crops and thus exclude forage legumes such as clover and alfalfa. The United Nations Food and Agriculture Organization defines "BEANS, DRY" (item code 176) as applicable only to species of Phaseolus.[6]

Cultivation

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.[7] As the pods mature, they turn yellow and dry up, and the beans inside change from green to their mature colour. Many beans are vines needing external support, such as "bean cages" or poles. Native Americans customarily grew them along with corn and squash (the so-called Three Sisters),[8] with the tall cornstalks acting as support for the beans.

More recently, the commercial "bush bean" which does not require support and produces all its pods simultaneously has been developed.[9]

History

See also: Columbian exchange

Beans were among the first plants to be domesticated. Broad or fava beans are in their wild state the size of a small fingernail; they were first gathered in Afghanistan and the Himalayan foothills.[10] An early cultivated form was grown in Thailand from the early seventh millennium BCE, predating ceramics.[11] 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.[12] In the Iliad (8th century BCE), there is a passing mention of beans and chickpeas cast on the threshing floor.[13]

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.[14] 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.[15]

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[16] 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.[17]

pre-Columbian people as far north as the Atlantic seaboard grew beans in the "Three Sisters" method of companion planting. The beans were interplanted with maize and squash.[18] Beans were cultivated across Chile in Pre-Hispanic times, likely as far south as the Chiloé Archipelago.[19]

Taxonomic range

Most beans are legumes, but from different genera, native to different regions.[20]

Genus Species and Common Varieties Probable Homeland Distribution, Cultivation and Climate Notes
Phaseolus P. vulgaris: Kidney Bean, Pinto Bean, Navy Bean (Cannellini, Haricot Beans/French Beans/Pole Beans/Bush Beans), Black Beans, Borlotti Beans

P. lunatus: Lima Beans

P. coccineus: Runner Beans, Flat Beans

P. acutifolius: Tepary Bean

The Americas Tropical, Subtropical, Warm Temperate Some contain high levels of toxic phytohemagglutinin.[21][22][23]
Pisum P. sativum: Green Peas/Garden Peas, White Peas, Yellow Peas, Field Peas, Snow Peas, Snap Peas Mediterranean Subtropical, Temperate, Occasionally Cool Tropical
Vigna V. radiata: Mung Bean

V. mungo: Urad

V. unguiculata (Cowpeas): Yardlong bean, Black-eyed Peas

V. aconitifolia: Moth bean

V. angularis: 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)

V. ervilia: Bitter vetch

V. sativa: Common vetch

Near East Subtropical, Temperate Causes Favism in susceptible people.[24][25]
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,[26] and smaller amounts of other psychoactive compounds. Can also cause itching and rashes on contact.
Lupinus L. albus: White Lupin

L. mutabilis: Tarwi/Andean Lupin

The Mediterranean, Balkans, Levant (albinus), The Andes (mutabilis) Subtropical, Temperate Requires soaking to remove toxins.[27]
Ceratonia C. siliqua: Carob bean Mediterranean, Middle East Subtropical, Arid Subtropical, Hot Temperate
Canavalia C. gladiata: Sword Bean

C. ensiformis: 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 Pea

L. tuberosus: Tuberous Pea

Balkans, India or Asia Subtropical Can cause Lathyrism if used as staple.[28][29]

Production

Main article: Legume § Production

The production data for legumes are published by FAO in three categories:

  1. Pulses dry: all mature and dry seeds of leguminous plants except soybeans and groundnuts.
  2. Oil crops: soybeans and groundnuts.
  3. Fresh vegetable: immature green fresh fruits of leguminous plants.

The following is a summary of FAO data.[30]

Production of legumes (million metric tons)
Crops
[FAO code][31] 		1961 1981 2001 2015 2016 Ratio
2016 /1961 		Remarks
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.

Top producers, pulses, total [1726][32]
(million metric tons)
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),[33] is India, followed by Myanmar (Burma) and Brazil. In Africa, the most important producer is Tanzania.[34]

Top ten dry beans (Phaseolus spp) producers, 2020
Country Production
(tonnes) 		Footnote
 India 5,460,000 F
 Myanmar 3,053,012
 Brazil 3,035,290 A
 United States 1,495,180 *
 China 1,281,586
 Tanzania 1,267,648 F
 Mexico 1,056,071
 Kenya 774,366 F
 Argentina 633,823 *
 Uganda 603,980
 World 27,545,942 A

No symbol = official figure, P = official figure, F = FAO estimate, * = unofficial/semi-official/mirror data, C = calculated figure A = aggregate (may include official, semi-official or estimates)

Source: UN Food and Agriculture Organization (FAO)[35]

Nutrition

Green beans, raw
Nutritional value per 100 g (3.5 oz)
Energy31 kcal (130 kJ)
6.97 g
Sugars3.26 g
Dietary fiber2.7 g
0.22 g
1.83 g
Vitamins and minerals
VitaminsQuantity
%DV†
Thiamine (B1)
7%
0.082 mg
Riboflavin (B2)
8%
0.104 mg
Niacin (B3)
5%
0.734 mg
Vitamin B6
8%
0.141 mg
Folate (B9)
8%
33 μg
Vitamin C
14%
12.2 mg
MineralsQuantity
%DV†
Calcium
3%
37 mg
Iron
6%
1.03 mg
Magnesium
6%
25 mg
Phosphorus
3%
38 mg
Potassium
7%
211 mg
Sodium
0%
6 mg
Zinc
2%
0.24 mg
Other constituentsQuantity
Water90.3 g
Link to USDA Database entry, FoodData Central
†Percentages estimated using US recommendations for adults,[36] except for potassium, which is estimated based on expert recommendation from the National Academies.[37]

Raw green beans are 90% water, 7% carbohydrates, 2% protein, and contain negligible fat. In a 100 grams (3.5 oz) 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).

Health concerns

Toxins

Main articles: 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.[38] A recommended method is to boil the beans for at least ten minutes; under-cooked beans may be more toxic than raw beans.[39]

Cooking beans, without bringing them to a boil, in a slow cooker at a temperature well below boiling may not destroy toxins.[39] 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.[40]

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 as of 2008.[40]

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.[41] Beans are a major source of dietary protein in Kenya, Malawi, Tanzania, Uganda and Zambia.[42]

Bacterial infection from bean sprouts

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,[43] some causing significant mortality.[44]

Antinutrients

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.[45][46]

Flatulence

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. A suitable oligosaccharide-cleaving enzyme is necessary to digest these sugar molecules. As a normal human digestive tract does not contain such enzymes, consumed oligosaccharides are typically digested by bacteria in the large intestine. This produces gases, such as methane as a byproduct, which are released as flatulence.[47][48][49][50]

See also

References

  1. ^ "Beans and peas are unique foods | ChooseMyPlate". www.choosemyplate.gov. Retrieved 24 January 2020.
  2. ^ Clark, Mellisa. "How to Cook Beans". New York Times Cooking. Retrieved 3 January 2020.
  3. ^ "bean (n.)". Online Etymology Dictionary. Retrieved 27 November 2024.
  4. ^ a b Cite error: The named reference MW_Collegiate was invoked but never defined (see the help page).
  5. ^ The American Heritage Dictionary of the English Language. Houghton Mifflin Harcourt. Archived from the original on 25 September 2015. Retrieved 3 May 2016.
  6. ^ a b "Definition And Classification Of Commodities (See Chapter 4)". FAO. 1994. Archived from the original on 12 October 2018. Retrieved 5 July 2012.
  7. ^ Shurtleff, William; Aoyagi, Akiko (1 October 2013). Early Named Soybean Varieties in the United States and Canada: Extensively Annotated Bibliography and Sourcebook. Soyinfo Center. ISBN 9781928914600. Retrieved 18 November 2017 – via Google Books.
  8. ^ Schneider, Meg. New York Yesterday & Today. Voyageur Press. ISBN 9781616731267. Retrieved 18 November 2017 – via Google Books.
  9. ^ "The Germination Of a Bean" (PDF). Microscopy-uk.org.uk. Archived (PDF) from the original on 9 October 2022. Retrieved 18 November 2017.
  10. ^ Kaplan, pp. 27 ff
  11. ^ Gorman, C.F. (1969). "Hoabinhian: A pebble-tool complex with early plant associations in southeast Asia". Science. 163 (3868): 671–3. Bibcode:1969Sci...163..671G. doi:10.1126/science.163.3868.671. PMID 17742735. S2CID 34052655.
  12. ^ Daniel Zohary and Maria Hopf Domestication of Plants in the Old World Oxford University Press, 2012, ISBN 0199549060, p. 114.
  13. ^ "And as in some great threshing-floor go leaping From a broad pan the black-skinned beans or peas." (Iliad xiii, 589).
  14. ^ Chazan, Michael (2008). World Prehistory and Archaeology: Pathways through Time. Pearson Education, Inc. ISBN 978-0-205-40621-0.
  15. ^ Bitocchi, Elena; Nanni, Laura; Bellucci, Elisa; Rossi, Monica; Giardini, Alessandro; et al. (3 April 2012). "Mesoamerican origin of the common bean (Phaseolus vulgaris L.) is revealed by sequence data". Proceedings of the National Academy of Sciences. 109 (14): E788–E796. doi:10.1073/pnas.1108973109. PMC 3325731. PMID 22393017.
  16. ^ Kaplan, p. 30: Domestication, besides involving selection for larger seed size, also involved selection for pods that did not curl and open when ripe, scattering the beans they contained.
  17. ^ Kaplan, p. 30
  18. ^ Mt. Pleasant, Jane (2006). "The science behind the Three Sisters mound system: An agronomic assessment of an indigenous agricultural system in the northeast". In Staller, John E.; Tykot, Robert H.; Benz, Bruce F. (eds.). Histories of Maize: Multidisciplinary Approaches to the Prehistory, Linguistics, Biogeography, Domestication, and Evolution of Maize. Amsterdam: Academic Press. pp. 529–537. ISBN 978-0-1236-9364-8.
  19. ^ Pardo B., Oriana; Pizarro, José Luis (2014). Chile: Plantas alimentarias Prehispánicas (in Spanish) (2015 ed.). Arica, Chile: Ediciones Parina. p. 162. ISBN 9789569120022.
  20. ^ "Legumes and Pulses". The Nutrition Source. 28 October 2019. Retrieved 7 April 2022.
  21. ^ Nyombaire, G.; Siddiq, M.; Dolan, K. (2007). "Effect of soaking and cooking on the oligosaccharides and lectins of red kidney beans (Phaseolus vulgaris L.)". Annual Report.
  22. ^ Nciri, Nader; Cho, Namjun (15 December 2017). "New research highlights: Impact of chronic ingestion of white kidney beans (Phaseolus vulgaris L. var. Beldia) on small-intestinal disaccharidase activity in Wistar rats". Toxicology Reports. 5: 46–55. doi:10.1016/j.toxrep.2017.12.016. ISSN 2214-7500. PMC 5735304. PMID 29270365.
  23. ^ Sun, Yufeng; Liu, Jiameng; Huang, Yatao; Li, Minmin; Lu, Jia; et al. (1 January 2019). "Phytohemagglutinin content in fresh kidney bean in China". International Journal of Food Properties. 22 (1): 405–413. doi:10.1080/10942912.2019.1590399. ISSN 1094-2912.
  24. ^ Belsey, Mark A. (1973). "The epidemiology of favism". Bulletin of the World Health Organization. 48 (1): 1–13. ISSN 0042-9686. PMC 2481045. PMID 4541143.
  25. ^ Tarhani, Fariba; Nezami, Alireza; Heidari, Ghobad; Abdolkarimi, Babak (18 August 2020). "Clinical Manifestations and Therapeutic Findings of the Children with Glucose-6-Phosphate Dehydrogenase Deficiency Presenting Favism". Endocrine, Metabolic & Immune Disorders Drug Targets. 21 (6): 1125–1129. doi:10.2174/1871530320999200818182905. PMID 32811422. S2CID 221182334.
  26. ^ Raina, Archana P.; Khatri, Renu (2011). "Quantitative Determination of L-DOPA in Seeds of Mucuna Pruriens Germplasm by High Performance Thin Layer Chromatography". Indian Journal of Pharmaceutical Sciences. 73 (4): 459–462. doi:10.4103/0250-474X.95651 (inactive 1 November 2024). ISSN 0250-474X. PMC 3374567. PMID 22707835.{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)
  27. ^ Schrenk, Dieter; Bodin, Laurent; Chipman, James Kevin; del Mazo, Jesús; Grasl-Kraupp, Bettina; Hogstrand, Christer; Hoogenboom, Laurentius (Ron); Leblanc, Jean-Charles; Nebbia, Carlo Stefano; Nielsen, Elsa; Ntzani, Evangelia (5 November 2019). "Scientific opinion on the risks for animal and human health related to the presence of quinolizidine alkaloids in feed and food, in particular in lupins and lupin-derived products". EFSA Journal. 17 (11): e05860. doi:10.2903/j.efsa.2019.5860. ISSN 1831-4732. PMC 7008800. PMID 32626161.
  28. ^ Haque, A.; Hossain, M.; Wouters, G.; Lambein, F. (1996). "Epidemiological Study of Lathyrism in Northwestern Districts of Bangladesh". Neuroepidemiology. 15 (2): 83–91. doi:10.1159/000109893. ISSN 0251-5350. PMID 8684587.
  29. ^ Jahan, K.; Ahmad, K. (February 1993). "Studies on neurolathyrism". Environmental Research. 60 (2): 259–266. Bibcode:1993ER.....60..259J. doi:10.1006/enrs.1993.1035. ISSN 0013-9351. PMID 8472656.
  30. ^ FAO STAT Production/Crops.
  31. ^ See Legume § Classification.
  32. ^ All legumes dry.
  33. ^ Dry beans does not include broad beans, dry peas, chickpea, lentil.
  34. ^ FAO Pulses and Derived Products Archived 7 December 2015 at the Wayback Machine.
  35. ^ "Major Food And Agricultural Commodities And Producers – Countries By Commodity". Fao.org. Archived from the original on 6 September 2015. Retrieved 2 February 2015.
  36. ^ United States Food and Drug Administration (2024). "Daily Value on the Nutrition and Supplement Facts Labels". FDA. Archived from the original on 27 March 2024. Retrieved 28 March 2024.
  37. ^ National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee to Review the Dietary Reference Intakes for Sodium and Potassium (2019). Oria, Maria; Harrison, Meghan; Stallings, Virginia A. (eds.). Dietary Reference Intakes for Sodium and Potassium. The National Academies Collection: Reports funded by National Institutes of Health. Washington, DC: National Academies Press (US). ISBN 978-0-309-48834-1. PMID 30844154. Archived from the original on 9 May 2024. Retrieved 21 June 2024.
  38. ^ "Natural toxins in food". www.who.int. Retrieved 7 April 2022.
  39. ^ a b "Foodborne Pathogenic Microorganisms and Natural Toxins Handbook: Phytohaemagglutinin". Bad Bug Book. United States Food and Drug Administration. Archived from the original on 9 July 2009. Retrieved 11 July 2009.
  40. ^ a b Vicky Jones (15 September 2008). "Beware of the beans: How beans can be a surprising source of food poisoning". The Independent. Retrieved 23 January 2016.
  41. ^ Shimelis, Emire Admassu; Rakshit, Sudip Kumar (2008). "Influence of natural and controlled fermentations on α-galactosides, antinutrients and protein digestibility of beans (Phaseolus vulgaris L.)". International Journal of Food Science & Technology. 43 (4): 658–665. doi:10.1111/j.1365-2621.2006.01506.x. ISSN 1365-2621.
  42. ^ Summary: Fermentation 'improves nutritional value of beans' Archived 22 May 2013 at the Wayback Machine (Sub Saharan Africa page, Science and Development Network website). Paper: Influence of natural and controlled fermentations on α-galactosides, antinutrients and protein digestibility of beans (Phaseolus vulgaris L.)
  43. ^ "Sprouts: What You Should Know". Foodsafety.gov. Retrieved 23 January 2016.
  44. ^ "Shiga toxin-producing E. coli (STEC): Update on outbreak in the EU (27 July 2011, 11:00)". European Centre for Disease Prevention and Control. 27 July 2011. Archived from the original on 15 March 2017.
  45. ^ Harrison, DC; Mellanby, E (October 1939). "Phytic acid and the rickets-producing action of cereals". Biochem. J. 33 (10): 1660–1680.1. doi:10.1042/bj0331660. PMC 1264631. PMID 16747083.
  46. ^ Ramiel Nagel (26 March 2010). "Living With Phytic Acid - Weston A Price". The Weston A Price Foundation. Retrieved 23 January 2016.
  47. ^ "Health | Experts make flatulence-free bean". BBC News. 25 April 2006. Archived from the original on 31 March 2009. Retrieved 25 February 2009.
  48. ^ "Flatulence – Overview – Introduction". Nhs.uk. Archived from the original on 21 February 2009. Retrieved 25 February 2009.
  49. ^ McGee, Harold (2003). Food and Cooking. Simon & Schuster. p. 486. ISBN 978-0684843285. Many legumes, especially soy, navy and lima beans, cause a sudden increase in bacterial activity and gas production a few hours after they're consumed. This is because they contain large amounts of carbohydrates that human digestive enzymes can't convert into absorbable sugars. These carbohydrates therefore leave the upper intestine unchanged and enter the lower reaches, where our resident bacterial population does the job we are unable to do.
  50. ^ Peter Barham (2001). The Science of Cooking. Springer. p. 14. ISBN 978-3-540-67466-5. we do not possess any enzymes that are capable of breaking down larger sugars, such as raffinose etc. These 3, 4 and 5 ring sugars are made by plants especially as part of the energy storage system in seeds and beans. If these sugars are ingested, they can't be broken down in the intestines; rather, they travel into the colon, where various bacteria digest them

Bibliography

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