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Soy milk or soymilk is a plant-based drink produced by soaking and grinding soybeans, boiling the mixture, and filtering out remaining particulates. It is a stable emulsion of oil, water, and protein. Its original form is a natural by-product of the manufacture of tofu. It became a common beverage in Europe and North America in the later half of the 20th century, especially as production techniques were developed to give it taste and consistency more closely resembling dairy milk. Along with similar vegetable-based "milks", like almond and rice milk, soy milk may be used as a substitute for dairy milk by individuals who are vegan or lactose intolerant.

Soy milk
Soy milk (2).jpg
Alternative namesSoya milk
Place of originChina
Inventeda. 1365[1][2][3]
Food energy
(per 100 g serving)
33 kcal (138 kJ)
Nutritional value
(per 100 g serving)
Protein2.86 g
Fat1.61 g
Carbohydrate1.74 g
Glycemic index 34 (low)
Soy milk
Chinese name
Chinese豆奶
Literal meaningbean milk
Literary Chinese name
Chinese豆乳
Literal meaningbean milk
Archaic Chinese name
Chinese菽乳
Literal meaningbean milk
Korean name
Hangul두유
Hanja豆乳
Japanese name
Kanji豆乳
Kanaとうにゅう
Doujiang
Taiwan breakfast with fresh soymilk flickr user goosmurf.jpg
A youtiao with a bowl of doujiang
Traditional Chinese豆漿
Simplified Chinese豆浆
Literal meaningsoybean broth
Historic name
Traditional Chinese豆腐漿
Simplified Chinese豆腐
Literal meaningtofu broth
Canned soy milk
Bottled soy milk "Vitamilk" in Thailand

Contents

NamesEdit

In China, the usual term doujiang (lit. "bean broth") is used for the traditional watery and beany beverage produced as a by-product of the production of tofu, whereas store-bought products designed to imitate the flavor and consistency of dairy milk are more often known as dounai ("bean milk"). In other countries, there are sometimes legal impediments to the equivalents of the name "soy milk". In such jurisdictions, the manufacturers of plant milks typically label their products the equivalent of "soy beverage" or "soy drink".

Prohibition on use of the designation 'soy milk' in the European UnionEdit

For example, in the European Union, "'Milk' means exclusively the normal mammary secretion obtained from one or more milkings without either addition thereto or extraction therefrom".[4] Often, only cow's milk is allowed to be named "milk" on its packaging, and any other milks must state the name of the respective animal: "goat milk" or "sheep milk". The naming of soy drink as soy milk became subject of a 2017 court case before the Court of Justice of the European Union after a German consumer protection group filed an unfair competition complaint about a company describing its soya and tofu products as 'milk' or 'cheese'. The Court of Justice ruled that such designations cannot be legally used for purely plant-based products and that additions indicating the plant origin of the products (soy milk) does not influence that prohibition.[5]

HistoryEdit

Soybeans originated in northeastern China and appear to have been domesticated around the 11th century BC,[6] but its use in soups and beverages are only attested at much later dates. Soy gruel was first noted in the 3rd century BC,[7][6][a] soy "wine" in the 4th century,[9][10] and a tofu broth (doufujiang) c. 1365 amid the collapse of the Mongol Yuan.[1][2][3] As doujiang, this drink remains a common watery form of soy milk in China, usually prepared from fresh soybeans. Its popularity increased during the Qing dynasty, apparently due to the discovery that gently heating doujiang for at least 90 minutes hydrolyzed its raffinose and stachyose, oligosaccharides which can cause flatulence and digestive pain among lactose-intolerant adults.[11][12] By the 18th century, it was popular enough that street vendors were hawking it;[13] in the 19th, it was also common to take a cup to tofu shops to get hot, fresh doujiang for breakfast. It was already often paired with youtiao, which was dipped into it.[14] The process was industrialized in early Republican China. By 1929, two Shanghai factories were selling over 1000 bottles a day and another in Beijing was almost as productive itself.[15] Following disruption from the Second World War and the Chinese Civil War, soy milk began to be marketed in soft drink-like fashion in Hong Kong, Singapore, and Japan in the 1950s.[16]

The first non-dairy milkalmond milk—was created in the Levant around the 13th century[17] and had spread to England by the 14th.[18] Soymilk was mentioned in various European letters from China beginning in the 17th century.[19] "Soy milk" entered the English language (as "soy-bean milk") in an 1897 USDA report.[20][21] Li Yuying established Caséo-Sojaïne, the first soy milk "dairy", in Colombes, France, in 1910; he received the first British and American patents for soy milk's manufacture in 1912 and 1913.[15] J.A. Chard began production of "Soy Lac" in New York City, United States, in 1917.[15] Harry W. Miller—an American businessman forced to relocate his factory from Shanghai owing to World War II—was similarly compelled by the USDA and the US dairy industry to use the term "Soya Lac" rather than "soy milk".[15] John Harvey Kellogg had been working with what he called "soymilk" at his Battle Creek Sanitarium since 1930, but was similarly compelled to market his acidophilus-enriched beverage as "Soygal" when it began commercial production in 1942.[22] A string of 40 court cases against Rich Products between 1949 and 1974 finally established that non-dairy "milks" and imitation dairy products were "a new and distinct food", rather than inferior and illegal knock-offs.[15] Cornell researchers established the enzyme lipoxygenase's responsibility for soy milk's "beany" flavor in 1966; the same research established a process for reducing or eliminating it from commercial products.[23] With Tetra Pak cartons extending its shelf-life, Hong Kong-based Vitasoy reintroduced soy milk to the US market in 1980 and brought it to 20 other countries within a few years.[23] Alpro similarly began production in Belgium in 1980, quickly becoming Europe's leading producer.[23] New production technology and techniques began to permit soy beverages with an appreciably more milk-like flavor and consistency in the mid-1980s.[24]

NutritionEdit

A cup (243 ml) serving of a generic unsweetened commercial nutrient-fortified brand of soy milk provides 80 calories from 4 g of carbohydrates (including 1 g of sugar), 4 g of fat and 7 g of protein.[26] This processed soy milk contains appreciable levels of vitamin A, B vitamins, and vitamin D in a range of 10 to 45% of the Daily Value, with calcium and magnesium also in significant content.[26] It has a glycemic index of 34±4.[28]

TasteEdit

Soy milk flavor quality differs according to the cultivar of soybean used in its production.[29] Even in China, the desirable sensory qualities are a mouthfeel (smooth but thick), color (off-white), and appearance (creamy) resembling milk.[30] These traits—along with a pleasing aroma—are positively correlated with a soy milk's content of proteins, soluble solids, and oil.[30] In the United States, testing suggests consumers prefer viscous soy milk with sweet aromatic flavors like vanilla and actively dislike the "beany" or "brothy" flavors resembling traditional doujiang.[31]

PreparationEdit

Soy milk is made from whole soybeans or full-fat soy flour.[32] The dry beans are soaked in water for a minimum of three hours up to overnight depending on the temperature of the water. The rehydrated beans then undergo wet grinding with enough added water to give the desired solids content to the final product which has a protein content of 1–4%, depending on the method of production.[32] The ratio of water to beans on a weight basis is 10:1 for traditional soy milk.[32] The resulting slurry or purée is brought to a boil in order to improve its taste properties by heat inactivating soybean trypsin inhibitor, improve its flavor, and to sterilize the product.[32] Heating at or near the boiling point is continued for a period of time, 15–20 minutes, followed by the removal of insoluble residues (soy pulp fiber) by filtration.[32] Processing requires the use of an anti-foaming agent or natural defoamer during the boiling step. Bringing filtered soy milk to a boil avoids the problem of foaming. It is generally opaque, white or off-white in color, and approximately the same consistency as cow's milk.[32] Quality attributes during preparation include germination time for the beans used, acidity, total protein and carbohydrates, phytic acid content, and viscosity.[32]

ConsumptionEdit

 
Soy milk soup with salt and vinegar, along with vegetables and wontons.

Soy milk is a common beverage in East Asian cuisines. In Chinese cuisine, "sweet" soy milk is made by adding cane sugar or simple syrup. "Salty" or "savory" soy milk is often combined with chopped pickled mustard greens, dried shrimp, youtiao croutons, chopped spring onions, cilantro, pork floss, and/or shallots, along with vinegar, sesame oil, soy sauce, and/or chili oil. Both are traditional breakfast foods, served hot or cold depending on the season or personal preference. At breakfast, it is often accompanied by starchy carbohydrate-rich foods like mantou (a thick, fluffy kind of roll or bun), youtiao (deep-fried dough sticks), and shaobing (sesame flatbread).

Japanese cuisine uses soy milk to make yuba and as an occasional base for nabemono.

In Korean cuisine, soy milk is used as the broth for making kongguksu, a cold noodle soup eaten mostly in summer.

In the west, soy milk is found in many vegan and vegetarian food products and can be used as a replacement for cow's milk in many recipes. Soy milk is also used in making imitation dairy products such as soy yogurt, soy cream, soy kefir and soy-based cheese analogues.

Health effectsEdit

If soy based products are consumed in large quantities this can lead to excess of certain phytoestrogens (the major soy isoflavones being genistein and daidzein) which are found in soy protein, which may have some of the effects of the human estrogen hormone. The highest levels of naturally occurring isoflavones are found in soy beverages.[33] Food science practitioners have called for greater awareness and consideration of the endochrine-disrupting properties of soy (especially on infants and small children given their hormone-sensitive organs) as global consumption increases.[34] Recent reviews have concluded that in spite of increasing preclinical and clinical studies, ‘appealing evidence is still lacking to support the overall positive risk-benefit profile of phytoestrogens’.[35] A 2017 Dutch literature review on the potential health effects of dietary phytoestrogens - found in a wide variety of foods, but especially in soy - concluded that while several potential health benefits of phytoestrogens have been reported, the current evidence on these beneficial health effects is not so obvious that they clearly outweigh the possible health risks.[36]

Animal studies and retrospective human studies have suggested (not causally shown) a higher associated risk of cancer, male infertility, and other health problems, which led the health ministry of Israel (where consumption of soy is high and and use of soy based baby formula is among the world’s highest per capita, due to kosher food practices) to issue recommendations that consumption of soy products be limited in young children and avoided, if possible, in infants. A committee of experts also advised that adults who eat soy products do so in moderation.[37] Since soy is goitrogenic, it was noted that pregnant women regularly consuming soya should be particularly mindful of this endocrine-disrupting property of soya (thyroid hormone being essential for normal brain development).[34]

On infantsEdit

The sale of soy formula varies geographically, ranging from 2 to 7 percent of infant formula sales in the U.K., Italy, and France, 12 percent in the United States, 13 percent in New Zealand, and up to 31.5 percent in Israel (see above).[38] Infants fed soya formula have the highest exposure to any non-pharmacological source of oestrogen-like compounds, and the timing of this exposure is critical. The timing of infant exposure to the isoflavones of soy in a traditional Asian diet is different from that in a Western diet. In an Asian diet soya consumption is moderate across the entire lifespan and exposure in breastfeeding infants is extremely low (isoflavones do not effectively transfer through lactation). Western babies on soya infant formula however, have their highest exposures in the first year of life which then plummets.[39]

A US National Toxicology Program expert panel stated: "The existing epidemiological literature on soy infant formula exposure is insufficient to reach a conclusion on whether soy infant formula does or does not cause adverse effects on development in humans" but based on data available up to 2009 concluded that there was “minimal concern” for adverse developmental effects in infants who consume soy formula.[40] A 2010 review suggested that perinatal phyto‐oestrogen exposure, such as that found in infants feeding on soy‐based formula, should be avoided, pending the availability of further data.[41] A 2018 study concluded that infants who consume soy formula present with changes to tissue consistent with those seen with exogenous estrogen.[42] The researchers added that the differences were subtle and that it is unknown whether the effects we found have long-term consequences for health and development. They also noted that American Academy of Pediatrics strongly recommends breastfeeding and for mothers who prefer giving formula, the AAP does not recommend soy formula for preterm infants (unless where hereditary disorders make infants unable to properly digest milk, such as galactosemia).[43] Other research by NIEHS scientists suggests that infant girls fed soy formula are more likely to develop severe menstrual pain as young adults.[44]

In 2003 such a kosher soy-based baby milk substitute by Remedia (a Heinz subsidiary) was found to be lacking in vitamin B1, after twenty Israeli babies were admitted to hospitals suffering from brain damage.[45]

On human reproductive healthEdit

On human reproductive health specifically, a 2012 Swiss literature review found a lack of large-scale clinical studies examining the potentially adverse effects of soy consumption. It concluded generally that the available studies found either no impact or revealed only minor detrimental effects.[46] A 2015 cohort study among 501 males, found that specifically, genistein and daidzein (the major soy isoflavones) were associated with a lower percentage of normal sperm and increased abnormalities in semen morphology.[47]

Ecological impactEdit

Using soybeans to make milk instead of raising cows may be ecologically advantageous.[48] Cows require much more energy in order to produce milk, since the farmer must feed the animal, which can consume up to 24 kilograms (53 lb) of food in dry matter basis and 90 to 180 litres (24 to 48 US gal) of water a day, producing an average of 40 kilograms (88 lb) of milk a day. Legumes, including the soybean plant, also replenish the nitrogen content of the soil in which they are grown.

The cultivation of soybeans in South America is a cause of deforestation[49] (specifically in the Amazon rainforest) and a range of other large-scale environmental harm.[50] However, the majority of soybean cultivation worldwide, especially in South America where cattle farming is widespread, is intended for livestock fodder rather than soy milk production.[49]

See alsoEdit

NotesEdit

  1. ^ This is sometimes used to argue for an earlier date for soy milk itself.[8]

ReferencesEdit

  1. ^ a b Han Yi, Yiya Yiyi. ‹See Tfd›(in Chinese)
  2. ^ a b Shurtleff & al. (2013), pp. 5 & 23–4.
  3. ^ a b Shurtleff & al. (2014), p. 9.
  4. ^ "Document 32013R1308: Regulation (EU) No 1308/2013 of the European Parliament and of the Council of 17 December 2013 Establishing a Common Organisation of the Markets in Agricultural Products...", EUR-Lex, Brussels: European Union, 20 December 2013.
  5. ^ "Dairy names for soya and tofu face new ban". 2017-06-14. Retrieved 2019-07-15.
  6. ^ a b Shurtleff & al. (2014), p. 5.
  7. ^ Xun Kuang, Xunzi. ‹See Tfd›(in Chinese)
  8. ^ Huang, 2008 & 51–2.
  9. ^ Wang Xizhi, Shijiu. ‹See Tfd›(in Chinese)
  10. ^ Shurtleff & al. (2014), p. 7.
  11. ^ Shurtleff & al. (2013), pp. 23–4.
  12. ^ Huang (2008), p. 52.
  13. ^ Shurtleff & al. (2013), p. 29.
  14. ^ Shurtleff & al. (2013), pp. 5 & 33.
  15. ^ a b c d e Shurtleff & al. (2013), p. 6.
  16. ^ Shurtleff & al. (2013), pp. 7–8.
  17. ^ Muhammad bin Hasan al-Baghdadi (1226), The Book of Dishes [كتاب الطبيخ, Kitab al-Ṭabīḫ], Baghdad. ‹See Tfd›(in Arabic)
  18. ^ The Forme of Cury, London, 1390.
  19. ^ Shurtleff & al. (2013), p. 5.
  20. ^ Langworthy (1897).
  21. ^ Shurtleff & al. (2009), p. 174.
  22. ^ Shurtleff & al. (2004).
  23. ^ a b c Shurtleff & al. (2013), p. 8.
  24. ^ Shurtleff & al. (2013), pp. 8–9.
  25. ^ "Milk, whole, 3.25% milkfat, with added vitamin D" Archived 2018-03-16 at the Wayback Machine, United States Department of Agriculture, Agricultural Research Service.
  26. ^ a b c "Basic Report: 16222, Soymilk (All Flavors), Unsweetened, with Added Calcium, Vitamins A and D", USDA Food Composition Database, Washington: US Department of Agriculture, Agricultural Research Service, 2016.
  27. ^ "Beverages, almond milk, unsweetened, shelf stable" Archived 2017-08-20 at the Wayback Machine, United States Department of Agriculture, Agricultural Research Service.
  28. ^ Atkinson & al. (2008).
  29. ^ Shi & al. (2015).
  30. ^ a b Ma & al. (2015).
  31. ^ Lawrence & al. (2016).
  32. ^ a b c d e f g Jiang, S.; Cai, W.; Xu, B. (2013). "Food quality improvement of soy milk made from short-time germinated soybeans". Foods (Basel, Switzerland). 2 (2): 198–212. doi:10.3390/foods2020198. PMC 5302266. PMID 28239109.
  33. ^ Gibaldi, Milo (2000-10). "Are phytoestrogens a "natural alternative" to estrogen replacement therapy?". Western Journal of Medicine. 173 (4): 273. ISSN 0093-0415. PMC 1071115. PMID 11017999. Check date values in: |date= (help)
  34. ^ a b Patisaul, Heather B. (2017/05). "Endocrine disruption by dietary phyto-oestrogens: impact on dimorphic sexual systems and behaviours". Proceedings of the Nutrition Society. 76 (2): 130–144. doi:10.1017/S0029665116000677. ISSN 0029-6651. Check date values in: |date= (help)
  35. ^ Jargin, Sergei V. (2014-12-15). "Soy and phytoestrogens: possible side effects". GMS German Medical Science. 12. doi:10.3205/000203. ISSN 1612-3174. PMC 4270274. PMID 25587246.
  36. ^ Rietjens, Ivonne M C M; Louisse, Jochem; Beekmann, Karsten (2017-6). "The potential health effects of dietary phytoestrogens". British Journal of Pharmacology. 174 (11): 1263–1280. doi:10.1111/bph.13622. ISSN 0007-1188. PMC 5429336. PMID 27723080. Check date values in: |date= (help)
  37. ^ Siegel-Itzkovich, Judy (2005-07-30). "Health committee warns of potential dangers of soya". The BMJ. 331 (7511): 254. ISSN 0959-8138. PMC 1181288. PMID 16052004.
  38. ^ "Soy Infant Formula". National Institute of Environmental Health Sciences. Retrieved 2019-07-15.
  39. ^ Patisaul, Heather B. (2017-5). "Endocrine disruption by dietary phyto-oestrogens: impact on dimorphic sexual systems and behaviours". The Proceedings of the Nutrition Society. 76 (2): 130–144. doi:10.1017/S0029665116000677. ISSN 0029-6651. PMC 5646220. PMID 27389644. Check date values in: |date= (help)
  40. ^ Adgent, Margaret A; Umbach, David M; Zemel, Babette S; Kelly, Andrea; Schall, Joan I; Ford, Eileen G; James, Kerry; Darge, Kassa; Botelho, Julianne C (2018-03-01). "A Longitudinal Study of Estrogen-Responsive Tissues and Hormone Concentrations in Infants Fed Soy Formula". The Journal of Clinical Endocrinology and Metabolism. 103 (5): 1899–1909. doi:10.1210/jc.2017-02249. ISSN 0021-972X. PMC 6456922. PMID 29506126.
  41. ^ Cederroth, Christopher R.; Auger, Jacques; Zimmermann, Céline; Eustache, Florence; Nef, Serge (2010). "Soy, phyto-oestrogens and male reproductive function: a review". International Journal of Andrology. 33 (2): 304–316. doi:10.1111/j.1365-2605.2009.01011.x. ISSN 1365-2605.
  42. ^ Adgent, Margaret A; Umbach, David M; Zemel, Babette S; Kelly, Andrea; Schall, Joan I; Ford, Eileen G; James, Kerry; Darge, Kassa; Botelho, Julianne C (2018-03-01). "A Longitudinal Study of Estrogen-Responsive Tissues and Hormone Concentrations in Infants Fed Soy Formula". The Journal of Clinical Endocrinology and Metabolism. 103 (5): 1899–1909. doi:10.1210/jc.2017-02249. ISSN 0021-972X. PMC 6456922. PMID 29506126.
  43. ^ "Babies fed soy-based formula have changes in reproductive system tissues: CHOP co-author of NIH-led study: Subtle estrogen-like responses in infants point to need for longer-term follow-up of effects". ScienceDaily. Retrieved 2019-07-15.
  44. ^ "Soy Infant Formula". National Institute of Environmental Health Sciences. Retrieved 2019-07-15.
  45. ^ "Israel investigates baby deaths from milk". The Independent. 2003-11-11. Retrieved 2019-07-15.
  46. ^ Cederroth, Christopher Robin; Zimmermann, Céline; Nef, Serge (2012-05-22). "Soy, phytoestrogens and their impact on reproductive health". Molecular and Cellular Endocrinology. Health Impacts Of Endocrine Disrupters. 355 (2): 192–200. doi:10.1016/j.mce.2011.05.049. ISSN 0303-7207.
  47. ^ Mumford, Sunni L; Kim, Sungduk; Chen, Zhen; Barr, Dana Boyd; Louis, Germaine M Buck (2015-11). "Urinary Phytoestrogens Are Associated with Subtle Indicators of Semen Quality among Male Partners of Couples Desiring Pregnancy123". The Journal of Nutrition. 145 (11): 2535–2541. doi:10.3945/jn.115.214973. ISSN 0022-3166. PMC 4620723. PMID 26423741. Check date values in: |date= (help)
  48. ^ "Livestock's long shadow – Environmental issues and options; Chapter 2, Livestock in geographic transition" (PDF). United Nations, Food and Agriculture Organization, Rome. 2006.
  49. ^ a b "Soy is Everywhere". World Wildlife Fund. Retrieved 14 August 2015.
  50. ^ "Environmental & social impacts of soy". World Wildlife Fund. Retrieved 14 August 2015.

Further readingEdit