Soy milk

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A can of Yeo's soy milk, poured into a glass

Soy milk (also called soymilk, soya milk, soybean milk, soy bean milk,
soy drink, or soy beverage) is a milk-like beverage made from soybeans.

Origins

Soy milk originated in China, a region where soybean was native and used as
food long before the existence of written records. Later on, the soybean and
soybean foods were transplanted to Japan. Soybean or "vegetable" milk is
reputed to have been discovered and developed by Liu An of the Han
Dynasty in China about 164 B.C. Liu An is also credited with the development
of "Doufu" (soybean curd) in China which 900 years later spread to Japan
where it is known as "tofu".

Traditional soy milk, a stable emulsion of oil, water and protein, is simply an
aqueous extract of whole soybeans. The liquid 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 (Soyajoy, Soylife, Miracle,...)

Nomenclature
The Mandarin Chinese term for what English speakers call soy milk is Dòu
jiāng (Chinese: 豆漿; lit. "soy liquid"). In Western nations, soy milk is more
commonly sold under the term Dòu nǎi (豆奶; lit. "soy milk") than dòu jiāng
(豆漿), although the two terms are often used interchangeably. However,
there is a product in China that is called Dòu nǎi (豆奶) which is a dry miscible
powder made of both cow and soy milk.

The Japanese term for soy milk is tounyū (豆乳).

In French, soy milk is typically referred to as boisson au soja/soya, though
the more colloquial lait de soja or simply soja are also used.

In Spanish soy milk is called leche de soya.

Soy milk is commonly available in vanilla and chocolate flavors as well as its
original unflavored form. Plain soy milk in America is also commonly
sweetened, though unsweetened varieties are available.

In many countries, this product may not be sold under the name milk since it
is not a dairy product, hence the name soy drink.

Prevalence

Soy milk has developed a cachet in premium coffee blends from Western
restaurant chains such as Starbucks and Dunkin' Donuts.

In Japan, the consumption of cow's milk now exceeds that of soy milk. Cafés
that offer soy milk tend to be foreign franchises. It is, however, almost
always available at Japanese tofu shops and supermarkets.

Soy milk has increased in popularity in the West as a substitute for cow's
milk. In some Western nations where vegetarianism has made inroads, it is
available upon request at some cafés and coffee franchises as a cow's milk
substitute, usually at an extra cost.

Health

Soy milk is nutritionally close to cow's milk, though most soy milk
commercially available today is enriched with added vitamins such as vitamin
B12. It naturally has about the same amount of protein as cow milk. Natural
soy milk contains little digestable calcium as it is bound to the bean's pulp,
which is insoluble in a human. To counter this, many manufacturers enrich
their products with calcium carbonate which can dissolve in the acid of the
stomach. Notably it has little saturated fat, which many consider to be a
benefit. Lower fat varieties, however, contain less protein than cow's milk.
Soy milk is promoted as a healthy alternative to cow's milk for reasons
including:

      Contains no antibiotics, hormones, cholesterol, or links to cancer,
       diabetes, and other diseases
      Diabetes management through its ability to control blood sugar levels.
       However, diabetics should be aware that most brands of soymilk -
       even those labelled "plain" or "organic" - are actually sweetened. Look
       for the word "unsweetened" on the label.
      Source of lecithin and vitamin E
      Lacks casein
      Safe for people with lactose intolerance or milk allergy
      Polyunsaturated and monounsaturated fats are good for your heart.
      Contains isoflavones, organic chemicals, that may possibly be
       beneficial to health.

In 1995 the New England Journal of Medicine (Vol.333, No. 5) published a
report from the University of Kentucky entitled "Meta-Analysis of the Effects
of Soy Protein Intake on Serum Lipids." It was financed by the PTI division of
DuPont,"The Solae Co."[1] St.Louis. This meta-analysis concluded that soy
protein is correlated with significant decreases in serum cholesterol, low
density lipoprotein (LDL), a.k.a. bad cholesterol, and triglyceride
concentrations. However, high density lipoprotein (HDL) a.k.a. good
cholesterol, did not increase. Soy phytoestrogens (isoflavones:genistein and
daidzein) adsorbed onto the soy protein were suggested as the agent
reducing serum cholesterol levels. On the basis of this research PTI, in 1998,
filed a petition with FDA for a health claim that soy protein may reduce
cholesterol and the risk of heart disease.

The FDA granted this health claim for soy: "25 grams of soy protein a day, as
part of a diet low in saturated fat and cholesterol, may reduce the risk of
heart disease." One serving of soy milk (1 cup or 240 mL), for instance,
contains 6 or 7 grams of soy protein.

In January, 2006 an American Heart Association review (in the journal
Circulation) of a decade-long study of soy protein benefits cast doubt on the
FDA-allowed "Heart Healthy" claim for soy protein. The panel also found that
soy isoflavones do not reduce post menopause "hot flashes" in women, nor
do isoflavones help prevent cancers of the breast, uterus, or prostate. Thus
soy isoflavones in the form of supplements is not recommended. Among the
conclusions the authors state, "In contrast, soy products such as tofu, soy
butter, soy nuts, or some soy burgers should be beneficial to cardiovascular
and overall health because of their high content of polyunsaturated fats,
fiber, vitamins, and minerals and low content of saturated fat. Using these
and other soy foods to replace foods high in animal protein that contain
saturated fat and cholesterol may confer benefits to cardiovascular
health."[2]
The original paper is in the journal Circulation: January 17, 2006[1]

[2]

However, the soy industry has also received similar criticism from the dairy
industry for reasons including:

         High levels of phytic acid
         Hemagglutinin content. Soybean hemagglutinins are glycoproteins that
          cause red blood cells to agglutinate or clump together. Hemagglutinins
          are concentrated in the whey protein fraction of soy milk.
          Hemagglutinating activity of raw soybeans is readily destroyed by
          moist heat treatment. This is similar to a substance found in flu
          viruses, although it is rather unlikely to be harmful unless the soy milk
          is taken intravenously.
         Processing of soybeans, including genetic modification, which may
          result in lysinoalanine or nitrosamines
         Trypsin inhibitors content
         Soy phytoestrogens as antithyroid agents
         Aluminum content.[citation needed]

Although in general soy milk is not suitable for babies or infants, there exist
baby formulas based on soy protein, i.e. soy milk, that are used primarily in
the case of lactose intolerant children, those allergic to cow's milk or parental
preference for a vegetarian or vegan diet. Heinz Farley's Soya Infant Formula
is suitable for vegans and is approved by the Vegan Society in the UK. These
formulas are commonly named "soy milk", but contain extra carbohydrates,
fat, vitamins, and minerals. However care must be taken that children with
"Soy protein intolerance" are not fed soy milk.

See Soy Health

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
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 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 dangerous problem of foaming. It is generally opaque, white or off-white
in color, and approximately the same consistency as cow's milk.

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
rancid, paint-like, off-flavors of traditional soymilk 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 soymilks have been heat treated in this manner to destroy
LOX.

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 often derivatives of
soy milk containing more water or added ingredients.

Home-made Recipe

A home recipe for those who want to try making their own. You will need a
blender, cheese cloth, a tall pot, clean containers, heavy clean rubber gloves,
water, and soybeans. Rinse the dry soybeans clean, cover with water and
soak overnight (8-12 hours). Put 3 cups of water and one cup of dry
soybeans in the blender, and grind until it is a little rougher than drip coffee
grinds. Dump into a tall pot. Repeat with the desired quantity in the same
ratio of dry beans to water. Be sure that the ground mix is only a third of the
height of the pot, or it will get messy.
Note: It is very important that there is no oil residue in the blender,
containers, or pots whatsoever. Even a small trace of oil will cause many soy
proteins to precipitate out of solution, rendering your efforts useless.

Boil the pot, while stirring. Once boiling, enzymatic deactivation from the
soybeans will cause severe foaming to occur, and the pot will bubble up
rapidly. Cut the heat and stir the bubbles down, and increase the heat again.
Repeat multiple times causing the solution to bubble up, and stirring it down.
After about 20 minutes the solution will cease foaming, so no more bubbles
will be created. This indicates the undesirable tasting enzymes are gone, so
for best taste always boil until the solution stops gassing off. At this point,
strain the mix through the cheesecloth into the containers. The solids should
be squeezed in the cheesecloth to get the most milk. Wear the thick gloves
while straining, the soy solids will be very hot. The residual solids are called
okara, and can be used in soyburgers, or as a meat-substitute additive to
things like pasta sauce. The soy milk containers should be refrigerated ASAP,
they will last 2-3 weeks.

Alternately, to make maximal use of the entire soy beans: Soak beans for at
least 5 hours and then cook overnight (at least 4 hours) in a slow-cooker
(crockpot). Do not fill the pot more than halfway for one batch. In the
morning, the beans should have turned to a slightly darker (mustard-like)
color. Then blend in blender with (at least) 3-5 cups of water for each cup of
soybeans. Filter the solution.

Cooking

Soy milk is found in many vegan and vegetarian food products and can be
used as a replacement for cow's milk in most recipes. Such substitution has a
low impact on foods like pancakes, but there is a noticeable difference when
making foods such as macaroni and cheese or quiche.

"Sweet" and "salty" soy milk are both traditional Chinese breakfast foods,
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 (搾菜),
dried shrimp and, for curdling, vinegar, garnished with youtiao croutons,
chopped scallion (spring onions), cilantro (coriander), meat floss (肉鬆; ròu
sōng), or shallot as well as sesame oil, soy sauce, chili oil or salt to taste.

Soy milk is used in many kinds of Japanese Cooking, such as in making yuba
as well as sometimes a base soup for nabemono.It is quite popular in Japan
right now, and can be found in an array of foods for its healthy qualities.
Kanebo Foods has released I.V, a soy milk-based ice cream sold at
convenience stores. It can even be found in ice pop form.
Tofu is produced from soy milk by further steps of curdling and then
draining.

Ecological impact

Using soybeans to make milk instead of raising cows is said to have
ecological advantages, as the amount of soy that could be grown using the
same amount of land would feed more people than if used to raise cows. This
is debated as grazing land for animals is very different from land used to
farm. 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, much of which is used in
animal feed, has led to losing large tracts of forest land leading to ecological
damage [3], [4].

It was an American soil scientist, Dr.Andrew McClung, who first devised a
method to grow soybeans in the Cerrado region of Brazil. He is being
rewarded with the 2006 World Food Prize. [5]

== Manufacturers ==RAHAB WAWERU;W.F.,et al.1967.Effect of processing
methods on oxidative off-flavors of soybean milk.ministry of agricvulture
Food Technol. 21: 1630-1633.

				
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