Soy milk
Encyclopedia
Soy milk and sometimes referred to as soy drink/beverage is a beverage made from soybean
s. A stable emulsion of oil, water, and protein
, it is produced by soaking dry soybeans and grinding them with water. Soy milk contains about the same proportion of protein
as cow's milk: around 3.5%; also 2% fat
, 2.9% carbohydrate
, and 0.5% ash
. Soy milk can be made at home with traditional kitchen tools or with a soy milk machine
.
The coagulated protein from soy milk can be made into tofu
, just as dairy milk
can be made into cheese
.
where a kitchen scene proving use of soy milk is incised on a stone slab dated around AD 25–220. 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 is rare prior to the 20th century and widespread usage before then is unlikely.
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. This legend first started in the 12th century and was not clearly stated until late 15th century in Bencao Gangmu, where Li was attributed to the development of tofu 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. However, it is also likely that Liu An has been falsely attributed to the development of tofu by writers after his time. However, some recent writers attributed Liu An to have developed tofu in 164 BC.
Plain soy milk is unsweetened, although some soy milk products are sweetened. Salted soy milk is prevalent in China.
The drink is very popular in the hawker
culture of Malaysia, with it being a standard offering accompanying meals at Malaysian Chinese
stalls. In Malaysia, soybean milk 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) to the beverage. Sellers of soybean milk 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". Yeo's
, a drink manufacturer in Singapore and Malaysia, markets a commercialized tinned or boxed version of soybean milk.
The drink is slowly becoming popular in India
as well, where it widely sold in Tetrapaks by various brands like Staeta
.
In the West, soymilk has become a popular alternative to cow's milk, with a roughly similar protein and fat content. 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 café
s and coffee
franchises as a cow's milk substitute
. However it should be noted that soy milk is not always suitable for vegans, or even vegetarians. The fortified vitamin D
may be derived from lanolin
, and many soy milk products still contain added dairy.
(though not the same amino acid
profile) as cow's milk. Natural soy milk contains little digestible calcium
as it is bound to the bean's pulp, which is insoluble in humans. To counter this, many manufacturers enrich their products with calcium carbonate
available to human digestion. Unlike cow's milk, it has little saturated fat
and no cholesterol
.
Soy products contain sucrose
as the basic disaccharide
, which breaks down into glucose
and fructose
. Since soy doesn't contain galactose
, a product of lactose breakdown, soy-based infant formulas can safely replace breast milk in children with galactosemia
. Like lactose-free cow's milk, soymilk contains no lactose, which makes it a good alternative for lactose-intolerant people. For patients without conditions that limit which sugars they can consume, there is no evidence to support any sugar-related health benefit or detriment to consuming soy milk instead of cow's milk.
The American Academy of Pediatrics considers soy milk a suitable alternative for children who cannot tolerate human or cow's milk, or whose parents opt for a vegan diet. They find no medical benefit to using soy milk instead of human or cow's milk.
Soy milk, like cow's milk, varies in fat content, but the most commonly sold varieties have less fat than whole milk, similar fat content to 2% milk, and more fat than skim/nonfat milk.
Though it has been suggested that soy consumption is associated with a reduction in low-density lipoprotein ("bad cholesterol") and triglycerides, a 2006 study of a decade of soy protein consumption found no association between soy intake and health benefits such as cardiovascular health or cancer rates, and no benefit for women undergoing menopause
. Soy was able to replace animal protein, foods high in saturated fats, and other sources of dietary fiber
, vitamins and minerals.
However, much of the mineral content in soy milk is unassimilable because of high content of phytic acid
in soy milk. If soy milk is made into tempeh
, the phytic acid content is cut in half.
Research has refuted claims that soy affects sperm quality and bone mineral density.
, 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 profound 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. The pancreas naturally secretes proteases to digest a protein meal. Eating raw soybeans on a regular basis causes the pancreas to hypersecrete, leading to benign tumors of the pancreas.
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. It is 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 from forming by a rapid hydration 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 bland soy milks have been heat treated in this manner to destroy LOX.
In 1969, Mattick and Hand at Cornell University made the important discovery 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) important for 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. An example of a triple LOX-free soybean is the American soybean named "Laura".
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.
Commercial products labeled "soy drink" in the West are commonly sold in countries where the word "milk" is available by law only for cow milk. Examples: Australia, Canada, Europe.
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 milk 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 crouton
s, 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.
Nutrients in 100 ml of fortified soymilk "Alpro Soya" versus semi skimmed and fat free milk:
s 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. 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.
In Brazil
, the explosion of soybean cultivation has led to losing large tracts of forest land leading to ecological damage. These particular cleared forests are planted with soy intended for animal agricultural enterprises (especially beef
and pork
production), not for human consumption.
The American soil scientist Dr. Andrew McClung was the first to devise a method to grow soybeans in the Cerrado
region of Brazil. He was awarded with the 2006 World Food Prize
.
Soybean
The soybean or soya bean is a species of legume native to East Asia, widely grown for its edible bean which has numerous uses...
s. A stable emulsion of oil, water, and protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
, it is produced by soaking dry soybeans and grinding them with water. Soy milk contains about the same proportion of protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
as cow's milk: around 3.5%; also 2% fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
, 2.9% carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
, and 0.5% ash
Ash (analytical chemistry)
In analytical chemistry, ashing is the process of mineralization for preconcentration of trace substances prior to chemical analysis. Ash is the name given to all non-aqueous residue that remains after a sample is burned, and consist mostly of metal oxides....
. Soy milk can be made at home with traditional kitchen tools or with a soy milk machine
Soy milk maker
A soy milk maker is a small kitchen appliance which automatically cooks soy milk, a non-dairy beverage made from soy beans. Soy milk makers work similarly to a combination between a home blender and an automatic coffee maker...
.
The coagulated protein from soy milk can be made into tofu
Tofu
is a food made by coagulating soy milk and then pressing the resulting curds into soft white blocks. It is part of East Asian and Southeast Asian cuisine such as Chinese, Japanese, Korean, Indonesian, Vietnamese, and others. There are many different varieties of tofu, including fresh tofu and tofu...
, just as dairy milk
Milk
Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...
can be made into cheese
Cheese
Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms....
.
Origins
The oldest evidence of soy milk production is from ChinaChina
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
where a kitchen scene proving use of soy milk is incised on a stone slab dated around AD 25–220. It also appeared in a chapter called Four Taboos (Szu-Hui) in the AD 82 book called Lunheng
Lunheng
The Lunheng is a wide-ranging Chinese classic text containing critical essays by Wang Chong on natural science, Chinese mythology, philosophy, and literature.-Title:...
by Wang Chong
Wang Chong
Wang Chong , courtesy name Zhongren , was a Chinese philosopher active during the Han Dynasty. He developed a rational, secular, naturalistic and mechanistic account of the world and of human beings and gave a materialistic explanation of the origin of the universe. His main work was the Lùnhéng...
, possibly the first written record of soy milk. Evidence of soy milk is rare prior to the 20th century and widespread usage before then is unlikely.
According to popular tradition in China, soy milk was developed by Liu An
Liu An
Líu Ān was a Chinese prince and advisor to his nephew, Emperor Wu of Han of the Han Dynasty in China and the legendary inventor of t'ai chi...
for medicinal purposes, although there is no historical evidence for this legend. This legend first started in the 12th century and was not clearly stated until late 15th century in Bencao Gangmu, where Li was attributed to the development of tofu 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. However, it is also likely that Liu An has been falsely attributed to the development of tofu by writers after his time. However, some recent writers attributed Liu An to have developed tofu in 164 BC.
Translations of "soy milk" in Asian languages
- East Asia:
- Mandarin Chinese: the most common terms are "豆漿" (PinyinPinyinPinyin is the official system to transcribe Chinese characters into the Roman alphabet in China, Malaysia, Singapore and Taiwan. It is also often used to teach Mandarin Chinese and spell Chinese names in foreign publications and used as an input method to enter Chinese characters into...
: dòujiāng; lit. bean + slurry) and "豆奶" (PinyinPinyinPinyin is the official system to transcribe Chinese characters into the Roman alphabet in China, Malaysia, Singapore and Taiwan. It is also often used to teach Mandarin Chinese and spell Chinese names in foreign publications and used as an input method to enter Chinese characters into...
: dòunǎi; lit. bean + milk) - JapaneseJapanese languageis a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...
: tōnyū (豆乳, lit. bean + milk) - Taiwanese: tau linng (豆奶)
- KoreanKorean languageKorean is the official language of the country Korea, in both South and North. It is also one of the two official languages in the Yanbian Korean Autonomous Prefecture in People's Republic of China. There are about 78 million Korean speakers worldwide. In the 15th century, a national writing...
: "두유" (豆乳) du yu ("두" du and "유" yu represent soy and milk respectively)
- Mandarin Chinese: the most common terms are "豆漿" (Pinyin
- South-east Asia:
- MalayMalay languageMalay is a major language of the Austronesian family. It is the official language of Malaysia , Indonesia , Brunei and Singapore...
: air kacang soya, susu soya, air tauhu - IndonesianIndonesian languageIndonesian is the official language of Indonesia. Indonesian is a normative form of the Riau Islands dialect of Malay, an Austronesian language which has been used as a lingua franca in the Indonesian archipelago for centuries....
: susu kacang kedelai, susu kedelai - Singaporean Hokkien (Chinese dialect)Singaporean HokkienSingaporean Hokkien is a local variant of the Hokkien dialect spoken in Singapore. It is closely related to the Southern Malaysian Hokkien spoken in Southern Malaysia as well as Riau Hokkien spoken in the Indonesian province of Riau...
: 豆花水, Pe̍h-oē-jī: tau hoe chúi - ThaiThai languageThai , also known as Central Thai and Siamese, is the national and official language of Thailand and the native language of the Thai people, Thailand's dominant ethnic group. Thai is a member of the Tai group of the Tai–Kadai language family. Historical linguists have been unable to definitively...
: น้ำเต้าหู้ nám dtâo-hôo - VietnameseVietnamese languageVietnamese is the national and official language of Vietnam. It is the mother tongue of 86% of Vietnam's population, and of about three million overseas Vietnamese. It is also spoken as a second language by many ethnic minorities of Vietnam...
: sữa đậu nành (lit. "milk" + "soy bean").
- Malay
Prevalence
The drink is very popular in the hawker
Hawker (trade)
A hawker is a vendor of merchandise that can be easily transported; the term is roughly synonymous with peddler or costermonger. In most places where the term is used, a hawker sells items or food that are native to the area...
culture of Malaysia, with it being a standard offering accompanying meals at Malaysian Chinese
Malaysian Chinese
Malaysian Chinese is a Malaysian of Chinese origin. Most are descendants of Chinese who arrived between the fifteenth and the mid-twentieth centuries. Within Malaysia, they are usually simply referred to as "Chinese" in all languages. The term Chinese Malaysian is also sometimes used to refer to...
stalls. In Malaysia, soybean milk is usually flavoured with either white or brown sugar syrup. The consumer also has the option to add grass jelly
Grass jelly
Grass jelly, or Leaf jelly, is a jelly-like dessert found in China, Hong Kong, Taiwan and Southeast Asia. It is sold in cans or packets in Asian supermarkets.-Preparation:...
, known as leong fan or "cincau" (in the Malay language) to the beverage. Sellers of soybean milk in Penang usually also offer bean curd
Douhua
Douhua or doufuhua is a Chinese dessert made with very soft tofu. It is also referred to as tofu pudding and soybean pudding.-History:...
, 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". Yeo's
Yeo Hiap Seng
Yeo Hiap Seng Limited is an investment holding company as well as a drink manufacturer in Singapore and Malaysia. It produces its own Asian drinks and has the license from Pepsico to produce Pepsi, 7 Up, Mountain Dew, Mirinda and Mug Root Beer...
, a drink manufacturer in Singapore and Malaysia, markets a commercialized tinned or boxed version of soybean milk.
The drink is slowly becoming popular in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
as well, where it widely sold in Tetrapaks by various brands like Staeta
Staeta (Soy Milk)
Staeta is a brand of soy milk that has been sold in India since 2004. Staeta Soy Milk is manufactured and distributed by ProSoya Foods Pvt. Ltd.- History :ProSoya Foods Pvt. Ltd started operations in India in 2004. It is promoted by Dr...
.
In the West, soymilk has become a popular alternative to cow's milk, with a roughly similar protein and fat content. Soy milk is commonly available in vanilla
Vanilla
Vanilla is a flavoring derived from orchids of the genus Vanilla, primarily from the Mexican species, Flat-leaved Vanilla . The word vanilla derives from the Spanish word "", little pod...
and chocolate
Chocolate
Chocolate is a raw or processed food produced from the seed of the tropical Theobroma cacao tree. Cacao has been cultivated for at least three millennia in Mexico, Central and South America. Its earliest documented use is around 1100 BC...
flavors as well as its original unflavored form. In some Western countries where veganism
Veganism
Veganism is the practice of eliminating the use of animal products. Ethical vegans reject the commodity status of animals and the use of animal products for any purpose, while dietary vegans or strict vegetarians eliminate them from their diet only...
has made inroads, it is available upon request at café
Café
A café , also spelled cafe, in most countries refers to an establishment which focuses on serving coffee, like an American coffeehouse. In the United States, it may refer to an informal restaurant, offering a range of hot meals and made-to-order sandwiches...
s and coffee
Coffee
Coffee is a brewed beverage with a dark,init brooo acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia,...
franchises as a cow's milk substitute
Milk substitute
A milk substitute is a liquid that replaces milk in a diet or recipe. This overlaps with but is distinct from the group of milk-like liquids called "milks" because of their similarity to the liquid produced by mammary glands....
. However it should be noted that soy milk is not always suitable for vegans, or even vegetarians. The fortified vitamin D
Vitamin D
Vitamin D is a group of fat-soluble secosteroids. In humans, vitamin D is unique both because it functions as a prohormone and because the body can synthesize it when sun exposure is adequate ....
may be derived from lanolin
Lanolin
Lanolin , also called Adeps Lanae, wool wax or wool grease, is a yellow waxy substance secreted by the sebaceous glands of wool-bearing animals. Most lanolin used by humans comes from domestic sheep...
, and many soy milk products still contain added dairy.
Health impact
Soy milk has about the same amount of proteinProtein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
(though not the same amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
profile) as cow's milk. Natural soy milk contains little digestible calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
as it is bound to the bean's pulp, which is insoluble in humans. To counter this, many manufacturers enrich their products with calcium carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
available to human digestion. Unlike cow's milk, it has little saturated fat
Saturated fat
Saturated fat is fat that consists of triglycerides containing only saturated fatty acids. Saturated fatty acids have no double bonds between the individual carbon atoms of the fatty acid chain. That is, the chain of carbon atoms is fully "saturated" with hydrogen atoms...
and no cholesterol
Cholesterol
Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...
.
Soy products contain sucrose
Sucrose
Sucrose is the organic compound commonly known as table sugar and sometimes called saccharose. A white, odorless, crystalline powder with a sweet taste, it is best known for its role in human nutrition. The molecule is a disaccharide composed of glucose and fructose with the molecular formula...
as the basic disaccharide
Disaccharide
A disaccharide or biose is the carbohydrate formed when two monosaccharides undergo a condensation reaction which involves the elimination of a small molecule, such as water, from the functional groups only. Like monosaccharides, disaccharides form an aqueous solution when dissolved in water...
, which breaks down into glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
and fructose
Fructose
Fructose, or fruit sugar, is a simple monosaccharide found in many plants. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847...
. Since soy doesn't contain galactose
Galactose
Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....
, a product of lactose breakdown, soy-based infant formulas can safely replace breast milk in children with galactosemia
Galactosemia
Galactosemia is a rare genetic metabolic disorder that affects an individual's ability to metabolize the sugar galactose properly. Although the sugar lactose can metabolize to galactose, galactosemia is not related to and should not be confused with lactose intolerance...
. Like lactose-free cow's milk, soymilk contains no lactose, which makes it a good alternative for lactose-intolerant people. For patients without conditions that limit which sugars they can consume, there is no evidence to support any sugar-related health benefit or detriment to consuming soy milk instead of cow's milk.
The American Academy of Pediatrics considers soy milk a suitable alternative for children who cannot tolerate human or cow's milk, or whose parents opt for a vegan diet. They find no medical benefit to using soy milk instead of human or cow's milk.
Soy milk, like cow's milk, varies in fat content, but the most commonly sold varieties have less fat than whole milk, similar fat content to 2% milk, and more fat than skim/nonfat milk.
Though it has been suggested that soy consumption is associated with a reduction in low-density lipoprotein ("bad cholesterol") and triglycerides, a 2006 study of a decade of soy protein consumption found no association between soy intake and health benefits such as cardiovascular health or cancer rates, and no benefit for women undergoing menopause
Menopause
Menopause is a term used to describe the permanent cessation of the primary functions of the human ovaries: the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and the subsequent shedding of the uterine lining...
. Soy was able to replace animal protein, foods high in saturated fats, and other sources of dietary fiber
Dietary fiber
Dietary fiber, dietary fibre, or sometimes roughage is the indigestible portion of plant foods having two main components:* soluble fiber that is readily fermented in the colon into gases and physiologically active byproducts, and* insoluble fiber that is metabolically inert, absorbing water as it...
, vitamins and minerals.
However, much of the mineral content in soy milk is unassimilable because of high content of phytic acid
Phytic acid
Phytic acid is the principal storage form of phosphorus in many plant tissues, especially bran and seeds. Phytate is not digestible to humans or nonruminant animals, however, so it is not a source of either inositol or phosphate if eaten directly...
in soy milk. If soy milk is made into tempeh
Tempeh
Tempeh , or tempe , is a traditional soy product originally from Indonesia. It is made by a natural culturing and controlled fermentation process that binds soybeans into a cake form, similar to a very firm vegetarian burger patty...
, the phytic acid content is cut in half.
Research has refuted claims that soy affects sperm quality and bone mineral density.
Preparation
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 inhibitorTrypsin inhibitor
Trypsin inhibitors are chemicals that reduce the availability of trypsin, an enzyme essential to nutrition of many animals, including humans.There are four commercial sources of trypsin inhibitors....
, 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 profound 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. The pancreas naturally secretes proteases to digest a protein meal. Eating raw soybeans on a regular basis causes the pancreas to hypersecrete, leading to benign tumors of the pancreas.
When soybeans absorb water, the endogenous enzyme, Lipoxygenase
Lipoxygenase
Lipoxygenases are a family of iron-containing enzymes that catalyse the dioxygenation of polyunsaturated fatty acids in lipids containing a cis,cis-1,4- pentadiene structure. It catalyses the following reaction:...
(LOX), EC 1.13.11.12 linoleate:oxidoreductase, catalyzes a reaction between polyunsaturated fatty acids and oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
{hydroperoxidation}. LOX initiates the formation of free radicals, which can then attack other cell components. Soybean seeds are the richest known sources of LOXs. It is thought to be a defensive mechanism by the soybean against fungal invasion.
In 1967, experiments at Cornell University
Cornell University
Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
and the New York State Agricultural Experiment Station
New York State Agricultural Experiment Station
The New York State Agricultural Experiment Station at Geneva, Ontario County, New York State, is an integral part of the New York State College of Agriculture and Life Sciences at Cornell University. It is a mission-oriented experiment station with a strong emphasis on applied research...
at Geneva, NY led to the discovery that paint-like, off-flavors of traditional soy milk can be prevented from forming by a rapid hydration 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 bland soy milks have been heat treated in this manner to destroy LOX.
In 1969, Mattick and Hand at Cornell University made the important discovery 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) important for 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. An example of a triple LOX-free soybean is the American soybean named "Laura".
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
Homogenization (chemistry)
Homogenization or homogenisation is any of several processes used to make a chemical mixture the same throughout.-Definition:Homogenization is intensive blending of mutually related substances or groups of mutually related substances to form a constant of different insoluble phases to obtain a...
as to be in permanent suspension.
Commercial products labeled "soy drink" in the West are commonly sold in countries where the word "milk" is available by law only for cow milk. Examples: Australia, Canada, Europe.
Cooking
Soy milk is found in many veganVeganism
Veganism is the practice of eliminating the use of animal products. Ethical vegans reject the commodity status of animals and the use of animal products for any purpose, while dietary vegans or strict vegetarians eliminate them from their diet only...
and vegetarian
Vegetarianism
Vegetarianism encompasses the practice of following plant-based diets , with or without the inclusion of dairy products or eggs, and with the exclusion of meat...
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
Mantou
Mantou, often referred to as Chinese steamed bun/bread, is a kind of steamed bun originating in China. They are typically eaten as a staple in northern parts of China where wheat, rather than rice, is grown. They are made with milled wheat flour, water and leavening agents...
(steamed rolls), youtiao (deep-fried dough), and shaobing
Shaobing
Shaobing or huoshao is a baked, layered flatbread with or without sesame on top, in Chinese cuisine. They can contain a variety of stuffing which can be grouped into two main flavors: savoury or sweet. Examples of fillings are red bean paste, black sesame paste, stir-fried mung beans with egg and...
(sesame flatbread). The soy milk is typically sweetened by adding cane sugar or, sometimes, simple syrup
Syrup
In cooking, a syrup is a thick, viscous liquid consisting primarily of a solution of sugar in water, containing a large amount of dissolved sugars but showing little tendency to deposit crystals...
. "Salty" soy milk is made with a combination of chopped pickled mustard greens, dried shrimp and, for curdling, vinegar, garnished with youtiao crouton
Crouton
A crouton is a small piece of sautéed or rebaked bread, often cubed and seasoned, that is used to add texture and flavor to salads, notably the Caesar salad, as an accompaniment to soups, or eaten as a snack food. The word crouton is derived from the French croûton, itself derived from croûte,...
s, chopped scallion (spring onions), cilantro
Coriander
Coriander is an annual herb in the family Apiaceae. Coriander is native to southern Europe and North Africa to southwestern Asia. It is a soft, hairless plant growing to tall. The leaves are variable in shape, broadly lobed at the base of the plant, and slender and feathery higher on the...
(coriander), meat floss
Rousong
Rousong , also sometimes called meat wool, meat floss, pork floss, pork sung, is a dried meat product that has a light and fluffy texture similar to coarse cotton, originating from Fujian. Rousong is used as a topping for many foods such as congee, tofu, and savory soy milk. It is also used as...
(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
Japanese cuisine
Japanese cuisine has developed over the centuries as a result of many political and social changes throughout Japan. The cuisine eventually changed with the advent of the Medieval age which ushered in a shedding of elitism with the age of shogun rule...
, such as in making yuba
Yuba (food)
Tofu skin also known as beancurd sheet, dried beancurd, paper, yuba or bean skin, is a Chinese and Japanese food product made from soybeans. During the boiling of soy milk, in an open shallow pan, a film or skin composed primarily of a soy protein–lipid complex forms on the liquid surface...
as well as sometimes a base soup for nabemono
Nabemono
Nabemono or simply called nabe, is a term referring to all varieties of Japanese steamboat dishes, also known as one pot dishes....
.
In Korean cuisine, soy milk is used as a soup for making kongguksu
Kongguksu
Kongguksu is a seasonal Korean noodle dish served in a cold soy milk broth. It comprises noodles made with wheat flour and soup made from ground soybeans...
, cold noodle soup eaten mostly in summer.
Tofu
Tofu
is a food made by coagulating soy milk and then pressing the resulting curds into soft white blocks. It is part of East Asian and Southeast Asian cuisine such as Chinese, Japanese, Korean, Indonesian, Vietnamese, and others. There are many different varieties of tofu, including fresh tofu and tofu...
is produced from soy milk by further steps of curdling and then draining.
Soy milk is also used in making soy yogurt
Soy yogurt
Soy yogurt, also referred to as Soya yogurt, Soygurt or Yofu , is yogurt prepared with soy milk.-Ingredients:...
, soy cream
Plant cream
Plant cream is a general term for any non-dairy cream analogue that is derived from a plant source. No formal or legal definition for plant cream exists in most countries...
, soy kefir
Kefir
Kefir is a fermented milk drink that originated with shepherds of the North Caucasus region, who discovered that fresh milk carried in leather pouches would occasionally ferment into an effervescent beverage...
and soy based cheese analogues.
Nutrition and health information
Nutrients in 8 ounces (250 ml) of plain soymilk: (Calories for soymilk does not add up)| Regular Soymilk | Lite Soymilk (reduced fat) | Whole cow milk | Fat-free cow milk | |
|---|---|---|---|---|
| Calories (kcal) | 90 | 70 | 149 | 83 |
| Protein (g) | 10.0 | 4.0 | 7.7 | 8.3 |
| Fat (g) | 4.0 | 2.0 | 8.0 | 0.2 |
| Carbohydrate (g) | 14.0 | 16.0 | 11.7 | 12.2 |
| Lactose Lactose Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,... (g) |
0.0 | 0.0 | 11.0 | 12.5 |
| Sodium (mg) | 120 | 100 | 105 | 103 |
| Iron (mg) | 1.8 | 0.6 | 0.07 | 0.07 |
| Riboflavin (mg) | 0.1 | 11.0 | 0.412 | 0.446 |
| Calcium (mg) | 80.0 | 80.0 | 276 | 299 |
Nutrients in 100 ml of fortified soymilk "Alpro Soya" versus semi skimmed and fat free milk:
| Enhanced Soymilk (Alpro Soya) | Semi skimmed cow milk | Fat free cow milk | |
|---|---|---|---|
| Calories (kcal) | 31 | 47 | 35 |
| Protein (g) | 3.3 | 3.6 | 3.6 |
| Carbohydrate (g) | 2.8 | 4.8 | 4.9 |
| - of which lactose (g) | 0.0 | 4.8 | 4.9 |
| Fat (g) | 1.8 | 1.8 | 0.3 |
| - of which saturates (g) | 0.3 | 1.1 | 0.1 |
| Sodium (mg) | 10 | 44 | 45 |
| Iron (mg) | 0.24 | 0.02 | 0.03 |
| Calcium (mg) | 120 | 124 | 129 |
| Vitamin A (mcg) | 1.0 | 6.0 | 3.5 |
| Riboflavin (Vit B2) (mg) | 0.21 | 0.25 | 0.10 |
| Vitamin B12 (mcg) | 0.38 | 0.9 | 0.4 |
| Vitamin D (mcg) | 0.75 | 2.5 | 0.0 |
Ecological impact
Using soybeanSoybean
The soybean or soya bean is a species of legume native to East Asia, widely grown for its edible bean which has numerous uses...
s to make milk instead of raising cows may be ecologically
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
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. 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.
In Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, the explosion of soybean cultivation has led to losing large tracts of forest land leading to ecological damage. These particular cleared forests are planted with soy intended for animal agricultural enterprises (especially beef
Beef
Beef is the culinary name for meat from bovines, especially domestic cattle. Beef can be harvested from cows, bulls, heifers or steers. It is one of the principal meats used in the cuisine of the Middle East , Australia, Argentina, Brazil, Europe and the United States, and is also important in...
and pork
Pork
Pork is the culinary name for meat from the domestic pig , which is eaten in many countries. It is one of the most commonly consumed meats worldwide, with evidence of pig husbandry dating back to 5000 BC....
production), not for human consumption.
The American soil scientist Dr. Andrew McClung was the first to devise a method to grow soybeans in the Cerrado
Cerrado
The Cerrado, is a vast tropical savanna ecoregion of Brazil, particularly in the states of Gioas and Minas Gerais...
region of Brazil. He was awarded with the 2006 World Food Prize
World Food Prize
The World Food Prize is an international award recognizing the achievements of individuals who have advanced human development by improving the quality, quantity or availability of food in the world.-The Prize:...
.
See also
- Hemp milkHemp milkHemp milk or Hemp Seed Milk, is a drink made from hemp seeds that are soaked and ground into water, yielding a creamy nutty beverage. It is marketed in health and fitness publications as a "new health food darling".- Health claims :According to Dr...
- Chinese cuisineChinese cuisineChinese cuisine is any of several styles originating in the regions of China, some of which have become highly popular in other parts of the world – from Asia to the Americas, Australia, Western Europe and Southern Africa...
- Dairy (animal) milkMilkMilk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...
- DouzhiDouzhiDouzhi is a dish from Beijing cuisine. It is similar to soy milk, but made from mung beans. It is a by-product of cellophane noodle production. It is generally slightly sour, with an egg-like smell.-External links:...
- Plant milkPlant milkthumb|right|250px|A cup of [[amazake]] .Plant milk is a general term for any milk-like product that is derived from a plant source. There is no formal or legal definition for plant milk...
- Soy milk makerSoy milk makerA soy milk maker is a small kitchen appliance which automatically cooks soy milk, a non-dairy beverage made from soy beans. Soy milk makers work similarly to a combination between a home blender and an automatic coffee maker...
- TofuTofuis a food made by coagulating soy milk and then pressing the resulting curds into soft white blocks. It is part of East Asian and Southeast Asian cuisine such as Chinese, Japanese, Korean, Indonesian, Vietnamese, and others. There are many different varieties of tofu, including fresh tofu and tofu...
(soy milk curd)
External links
- Cornell University Food and Brand Lab
- Soy Allergy Information Page Asthma and Allergy Foundation of AmericaAsthma and Allergy Foundation of AmericaThe Asthma and Allergy Foundation of America is a non-profit organization dedicated to finding a cure for and controlling asthma, food allergies, nasal allergies and other allergic diseases. AAFA's mission is also to educate the public about these diseases...