Soy milk

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Soy milk
Soy milk (2).jpg
Alternative names Soya milk
豆漿 or 豆花水 (Chinese: bean thick liquid, or bean flower water)
豆乳 (Japanese)
두유 or 豆乳 (Korean)
Place of origin China
Year of invention c. 1365
Food energy
(per 100 g serving)
33 kcal (138 kJ)
Nutritional value
(per 100 g serving)
Protein 2.86 g
Fat 1.61 g
Carbohydrate 1.74 g
Cookbook:Soy milk  Soy milk

Soy milk (soymilk or soya milk) is a plant milk produced by soaking dry soybeans and grinding them with water.

A traditional staple of Asian cuisine, soy milk is a stable emulsion of oil, water and protein. Soy milk can be produced at home using a soy milk machine.

History[edit]

Origins[edit]

The oldest evidence of soy milk production is from China where a kitchen scene proving use of soy milk was incised on a stone slab dated around AD 25–225.[1] It also appeared in a chapter called Four Taboos (Szu-Hui) in the AD 82 book called Lunheng by Wang Chong, possibly the first written record of soy milk. Evidence of soy milk outside of China is rare prior to the 20th century, and widespread usage before then is unlikely.[1]

According to popular tradition in China, soy milk was developed by Liu An for medicinal purposes, although there is no historical evidence for this legend.[1] This legend first appeared in the 12th century and was not clearly stated until late 15th century in Bencao Gangmu, where the development of tofu was attributed to Liu with no mention of soy milk. Later writers in Asia and the West additionally attributed development of soy milk to Liu An, assuming that he could not have made tofu without making soy milk. This may be incorrect. In addition, some recent writers claim Liu An developed tofu in 164 BC.[2]

Dates[edit]

  • c. 1365: Yiya Yiyi [Remnant Notions from I Ya], by Han Yi (in China) is the earliest document seen that mentions soymilk, which it calls doufujiang.
  • c. 1640: Soy milk is probably in use in China by the beginning of the Qing dynasty.
  • 1704: Soy milk is first mentioned in English by Domingo Fernandez Navarrete in his book A Collection of Voyages and Travels. Navarrete served as a Dominican missionary in China.
  • c. 1790: An undated painting of hawkers selling soy milk (doujiang) in China, by Yao Wenhan[3]
  • 1866: Soy milk is first discussed as a drink in its own right by the Frenchman Paul Champion, who traveled in China. In a French-language article he stated that the Chinese had taken their cups to tofu shops to get hot soymilk, which they drank for breakfast.
  • 1896: Soy milk is first referred to in the United States by Henry Trimble in the American Journal of Pharmacy.
  • 1897: The term soy-bean milk first appears in a U.S. government publication.[4]

Prevalence[edit]

Latte macchiato prepared with soy milk, topped with additional cinnamon
A packet of Melon-flavored soy drinks.

Only in China has soymilk (doujiang) long been used as a beverage.

Soy milk in a can

Traditionally it has been served hot, ladled from a caldron for breakfast, at the place where it was made either sweetened or as the base of a salted soup served with deep-fried crullers. It was not used to feed infants or as an infant formula.[5]

Starting in the 1920s, a small number of companies in China started to make and sell bottled soymilk.

In Hong Kong, Vitasoy was launched in 1940 by K.S. Lo as a nutritious food for refugees fleeing during World War II. By 1968 it had captured 25% of the Hong Kong soft drink market, second only to Coca-Cola.

In Japan, bottled soymilk arrived in about 1957. The first soymilk boom started in about 1980; the many brands of soymilk were all sold in 180 ml aseptic cartons.

Plain soy milk is unsweetened, although some soy milk products are sweetened. Salted soy milk is also consumed in China.[6]

Soy milk is very popular in the hawker culture of Malaysia and many other Southeast Asian countries, with it being a standard offering accompanying meals at Malaysian Chinese stalls. In Malaysia, soybean drink is usually flavoured with either white or brown sugar syrup. The consumer also has the option to add grass jelly, known as leong fan or "cincau" (in the Malay language, adopted from the Chinese equivalents) to the beverage.

Sellers of soybean beverage in Penang usually also offer bean curd, a related custard-like dessert, known to the locals as tau hua which is flavored with the same syrup as the soybean milk. In Indonesian it is known as "susu kedele". In Vietnam, the soymilk as well as the soy custard may be flavored with ginger or pandan, a grassy herb with a mild coconut-like flavor. More recently (since 2008), other optional additions to soy beverage have become popular among street vendors and drink stalls around Southeast Asia, including tapioca pearl, sweetened red bean, honey, and black tea.

Yeo's, a drink manufacturer in Singapore and Malaysia, markets a commercialized tinned or boxed version of soybean beverage.[7]

The drink is slowly becoming popular in India as well, where it widely sold in Tetrapaks by various brands like Staeta.

In the West, soy beverage has become a popular alternative to cow's milk, with a roughly similar protein and fat content.[8] Soy milk is commonly available in vanilla and chocolate flavors as well as its original unflavored form. In some Western countries where veganism has made inroads, it is available upon request at cafés and coffee franchises as a cow's milk substitute.

Health and nutrition[edit]

Soy milk, unsweetened, with added calcium and vitamins[9]
Nutritional value per 100 g (3.5 oz)
Energy 138 kJ (33 kcal)
1.74 g
Sugars 0.41 g
Dietary fiber 0.5 g
1.61 g
Saturated 0.206 g
Monounsaturated 0.392 g
Polyunsaturated 1.009 g
2.86 g
Vitamins
Thiamine (B1)
(13%)
0.154 mg
Riboflavin (B2)
(17%)
0.207 mg
Niacin (B3)
(1%)
0.165 mg
(2%)
0.082 mg
Vitamin B6
(4%)
0.049 mg
Folate (B9)
(0%)
1.5 μg
Vitamin B12
(46%)
1.11 μg
Vitamin C
(0%)
0 mg
Vitamin D
(8%)
1.2 μg
Trace metals
Calcium
(12%)
124 mg
Iron
(4%)
0.46 mg
Magnesium
(5%)
16 mg
Phosphorus
(5%)
32 mg
Potassium
(3%)
120 mg
Sodium
(2%)
37 mg
Other constituents
Water 93.14 g
Percentages are roughly approximated using US recommendations for adults.

Soy milk is a complete protein and has about the same amount of protein as cow's milk; it can replace animal protein and other sources of dietary fiber, vitamins and minerals.[10] Soy milk contains little digestible calcium because calcium is bound to the bean's pulp, which is indigestible by humans. To counter this, manufacturers enrich their products with calcium carbonate.[11] Unlike cow's milk, soy milk has little saturated fat and no cholesterol.

Soy products contain sucrose as the basic disaccharide, which breaks down into glucose and fructose. Since soy does not contain galactose, a product of lactose breakdown, soy-based infant formulas can safely replace breast milk in children with galactosemia.[12] Like lactose-free cow's milk, soymilk contains no lactose, which makes it an alternative for those who are lactose-intolerant.

It has been suggested that soy consumption is associated with a reduction in low-density lipoprotein ("bad cholesterol") and triglycerides.[13] Research has refuted claims that soy affects bone mineral density.[14] Research has found no link between soy and increased estrogen levels in men, although studies thus far have been limited in duration.[15]

For people who suffer from gout, purine in soy can make the condition worse. The US National Institutes of Health (NIH) recommends gout sufferers limit consumption of soy products, although also suggest that soy may have health benefits by reducing the risk for heart disease.[16]

Preparation[edit]

Soy milk can be made from whole soybeans or full-fat soy flour. The dry beans are soaked in water overnight or for a minimum of 3 hours or more 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. The ratio of water to beans on a weight basis should be about 10:1. The resulting slurry or purée is brought to a boil in order to improve its nutritional value by heat inactivating soybean trypsin inhibitor, improve its flavor and to sterilize the product. Heating at or near the boiling point is continued for a period of time, 15–20 minutes, followed by the removal of an insoluble residue (soy pulp fiber or okara) by filtration.

There is a simple yet important difference between traditional Chinese and Japanese soy milk processing: the Chinese method boils the filtrate (soy milk) after a cold filtration, while the Japanese method boils the slurry first, followed by hot filtration of the slurry. The latter method results in a higher yield of soy milk but 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.

For all raw soybean protein products, heat is necessary to destroy the activity of the protease inhibitors naturally present in the soybean. As the human pancreas naturally secretes proteases to digest a meal contain proteins, eating raw soybeans on a regular basis can cause the pancreas to hypersecrete, leading to benign tumors of the pancreas.[citation needed]

When soybeans absorb water, the endogenous enzyme, Lipoxygenase (LOX), EC 1.13.11.12 linoleate:oxidoreductase, catalyzes a reaction between polyunsaturated fatty acids and oxygen {hydroperoxidation}. LOX initiates the formation of free radicals, which can then attack other cell components. Soybean seeds are the richest known sources of LOXs, which are thought to be a defensive mechanism by the soybean against fungal invasion.

In 1967, experiments at Cornell University and the New York State Agricultural Experiment Station at Geneva, NY led to the discovery that paint-like, off-flavors of traditional soy milk can be prevented by a rapid hydration and grinding process of dehulled beans at temperatures above 80 °C. The quick moist heat treatment inactivates the LOX enzyme before it can have a significant negative effect on flavor. All modern soy milks have been heat treated in this manner to destroy LOX.

In 1969, Mattick and Hand[17] at Cornell University discovered that most of the so-called beany flavor in soybeans was not inherent in the beans themselves but was produced by the enzyme lipoxygenase when the split beans came in contact with water. Lipoxygenase could be inactivated and most of the beany flavor removed by either dropping unsoaked soybeans directly into boiling water or by removing any cracked or split beans prior to soaking, then carefully dropping the soaked beans into boiling water.

Normal mature soybeans actually contain three LOX isozymes (SBL-1, SBL-2, and SBL-3) that influence undesirable flavor development. One or more of these isozymes have recently (1998) been removed genetically from soybeans yielding soy milk with less cooked beany aroma and flavor and less astringency.

The University of Illinois has developed a soy milk that makes use of the entire soybean. What would normally constitute "insolubles" are ground so small by homogenization as to be in permanent suspension.[18]

Cooking[edit]

A bowl of soy milk soup seasoned with salt and vinegar, with vegetables and wonton dumplings.
Bottled soy milk as sold in Thailand

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.

"Sweet" and "salty" soy milk are both traditional Chinese breakfast foods, served either hot or cold, usually accompanied by breads like mantou (steamed rolls), youtiao (deep-fried dough), and shaobing (sesame flatbread). The soy beverage is typically sweetened by adding cane sugar or, sometimes, simple syrup. "Salty" soy milk is made with a combination of chopped pickled mustard greens, dried shrimp and, for curdling, vinegar, garnished with youtiao croutons, chopped scallion (spring onions), cilantro (coriander), meat floss (肉鬆; ròusōng), or shallot as well as sesame oil, soy sauce, chili oil or salt to taste.

Soy milk is used in many kinds of Japanese cuisine, such as in making yuba as well as sometimes a base soup for nabemono.

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

Tofu is produced from soy milk by further steps of curdling and then draining.

Soy milk is also used in making soy yogurt, soy cream, soy kefir and soy based cheese analogues.

Ecological impact[edit]

Using soybeans to make milk instead of raising cows may be ecologically advantageous, because the amount of soy that could be grown using the same amount of land would feed more people than if used to raise cows.[19] 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 pounds) of food in dry matter (DM) basis and 90 to 180 litres (25 to 50 gallons) of water a day, producing an average of 40 kilograms of milk a day. Because the soybean plant is a legume, it also replenishes the nitrogen content of the soil in which it is grown.

See also[edit]

General:

Notes[edit]

  1. ^ a b c History of Soymilk and Dairy-like Soymilk Products
  2. ^ History of Tofu
  3. ^ Huang, H.T. 2000. Science and Civilisation in China. Vol. 6. Biology and Biology and Biological Technology. Part V: Fermentations and Food Science. xxviii + 741 p. See p. 323.
  4. ^ C.F. Langworthy. 1897. "Soy beans as food for man." USDA Farmers' Bulletin No. 58. p. 20-23. July 7. The table, titled "Comparison of the composition of soy-bean milk and cows' milk," gives the nutritional composition of the two liquids.
    • See Shurtleff, William; Aoyagi, Akiko. History of Soymilk and Other Non-Dairy Milks (1226-2013), Lafayette, California, 2013.
  5. ^ Shurtleff, William; Aoyagi, Akiko. 2013. History of Soymilk and Other Non-Dairy Milks (1226-2013). Lafayette, California. 2,972 pp. (8,761 references; 233 photos and illustrations. Free online).
  6. ^ Chinese [1] Method of making salty soy beverage and Youtiao, recipe of 100 most commonly seen home cooking
  7. ^ Soy Bean Milk on Yeo's website. Retrieved 2008-10-08.
  8. ^ McGee, Harold. On Food and Cooking, Scribner, 2004, ISBN 0-684-80001-2, p.494
  9. ^ "Soymilk (all flavors), unsweetened, with added calcium, vitamins A and D", USDA
  10. ^ Sacks, F.; Lichtenstein, A.; Van Horn, L.; Harris, W.; Kris-Etherton, P.; Winston, M.; American Heart Association Nutrition Committee (2006). "Soy protein, isoflavones, and cardiovascular health: an American Heart Association Science Advisory for professionals from the Nutrition Committee". Circulation 113 (7): 1034–1044. doi:10.1161/CIRCULATIONAHA.106.171052. PMID 16418439.  edit
  11. ^ That calcium is often added, see Patricia Greenberg, The Whole Soy Cookbook, Random House, 1998, p. 15.
  12. ^ http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001405/
  13. ^ Anderson, J.; Johnstone, B.; Cook-Newell, M. (1995). "Meta-analysis of the effects of soy protein intake on serum lipids". The New England Journal of Medicine 333 (5): 276–282. doi:10.1056/NEJM199508033330502. PMID 7596371.  edit
  14. ^ Darling, A.; Millward, D.; Torgerson, D.; Hewitt, C.; Lanham-New, S. (2009). "Dietary protein and bone health: a systematic review and meta-analysis". The American journal of clinical nutrition 90 (6): 1674–1692. doi:10.3945/ajcn.2009.27799. PMID 19889822.  edit
  15. ^ Messina, M. (2010). "Soybean isoflavone exposure does not have feminizing effects on men: a critical examination of the clinical evidence". Fertility and Sterility 93 (7): 2095–2104. doi:10.1016/j.fertnstert.2010.03.002. PMID 20378106.  edit
  16. ^ "Soy". US National Institutes of Health. 2011-05-05. Retrieved 2012-10-10. 
  17. ^ History of Whole Dry Soybeans
  18. ^ http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.1976.tb01100.x/abstract
  19. ^ Livestock’s long shadow - Environmental issues and options

References[edit]

External links[edit]