Soya
The soya bean is the seed of the
leguminous soya bean plant. Soya foods have been a staple part of the
Chinese diet for over 4000 years but have
only been widely consumed in Western countries since the 1960's. Soya
foods include tofu, tempeh, textured vegetable protein (chunks, mince
etc), miso,
soya sauces, soya oil and margarine, and soya dairy alternatives.
Soya is an excellent source of high quality protein, is low in saturated
fats and is cholesterol free. Recent research has indicated soya has several
beneficial effects on health in addition to its nutritional benefits. Soya
beans contain high concentrations of several compounds which have demonstrated
anti-carcinogenic activity. These include isoflavonoids, protease inhibitors
and phytic acid. The low incidence of breast and colon cancer in China
and Japan has been partially attributed to the high consumption of soya
products. The low incidence of menopausal symptoms in Japanese women has
also been attributed to high consumption of soya. Soya diets have also
been shown to reduce levels of serum cholesterol.
 Textured
Vegetable Protein
Textured vegetable protein is basically defatted soya flour which has
been processed and dried to give a substance with a sponge-like texture which
may be flavoured to resemble meat. Soya beans are dehulled and their oil
extracted before being ground into flour. This flour is then mixed with water
to remove soluble carbohydrate and the residue is textured by either spinning
or extrusion. Extrusion involves passing heated soya residue from a high
pressure area to a reduced pressure area through a nozzle resulting in the
soya protein expanding. The soya protein is then dehydrated and may be either
cut into small chunks or ground into granules. Textured vegetable protein
may be purchased either unflavoured or flavoured to resemble meat. It is
prepared simply by mixing with water or stock and leaving to stand for a
few minutes, after which it may be incorporated into recipes as a meat substitute.
Soya protein is also available incorporated into various vegetarian burgers,
sausages, canned foods etc. As well as being a good source of fibre and high
quality protein, Textured vegetable protein is fortified with vitamin-B12.
Tofu
Tofu is soya bean curd made from coagulated soya milk. Soya beans
are soaked, crushed and heated to produce soya milk to which a coagulating
agent such as calcium sulphate or calcium chloride is added. The resulting
soya curd is then pressed to give tofu. Tofu is sometimes known as soya
cheese, and is sold as blocks packaged in water. It can be bought as silken
tofu, which is soft and creamy in texture, or as a denser, firmer version.
The firmer kind may also be purchased smoked or marinated. Tofu tends be
fairly bland tasting and is best used in recipes where flavour is imparted
by other ingredients. Firm tofu may be marinated, fried, stir-fried, deep-fried,
sauteed, diced and added to salads or casseroles. Silken tofu can be used
for dips, spreads, sauces and sweet dishes. As well as having a high protein
content, tofu also contains calcium, iron, and vitamins B1, B2 and B3.
(see Tofu Recipes)
Tempeh
Tempeh is a fermented soya bean paste made by inoculating cooked
soya beans with the mould Rhizopus oligosporous. This mould forms a mycelium
holding the soya beans together and is responsible for the black specks
in tempeh. Tempeh has a chewy texture and distinctive flavour and can be
used as a meat substitute in recipes. It may be deep-fried, shallow-fried,
baked or steamed.
Miso
Miso is a fermented condiment made from soya beans, grain (rice or
barley), salt and water. Miso production involves steaming polished rice
which is then inoculated with the fungus Aspergillus oryzae and left to
ferment to give an end product called koji. Koji is then mixed with soya
beans which have been heated and extruded to form strands, together with
salt and water. This is then left to ferment in large vats. Miso varies
widely in flavour, colour, texture and aroma. It is used to give flavour
to soups, stews, casseroles, and sauces.
Soya
Sauces
True soya sauce, called shoyu, is made by fermenting soya beans
with cracked roasted wheat, salt and water. Tamari is similar but slightly
stronger
and made without wheat (and so is gluten-free). Fermentation for shoyu
and tamari takes about one year. Much of the soya sauce available in supermarkets
is not true soya sauce but is made by chemical hydrolysis from defatted
soya flour, caramel colouring, and corn syrup without any fermentation
process.
Soya
Dairy Alternatives
Soya milk is an alternative to dairy milk and is
widely available in supermarkets and health food stores. It is most commonly
made by soaking
soya beans in water which are then strained to remove the fibre. It can
also be made from soya protein isolate or soya flour. Compared to full
fat cow's milk, soya milk has a lower fat content, a lower proportion of
saturated fat, and no cholesterol. It is low in carbohydrate and provides
a good source of protein. Some brands may be fortified with calcium, vitamin-D2,
vitamin-B12 and vitamin-B2. Soya milk provides an alternative to cow's
milk for people with cow's milk protein and lactose intolerance. Cow's
milk allergy is most common in infants, and specially formulated soya milks
are available for babies. Other soya milks are not suitable as sole foods
for young infants.
Previously, the media has linked soya milk with having a high aluminium
content. However, the aluminium content of soya milks is generally lower
than cow's milk, and falls well within acceptable limits dictated by
the World Health Organisation. Aluminium in soya milks can be regarded
as negligible. Certain infant formulas (both cow's milk and soya milk
based) produced from concentrates have been reported as having high levels
of aluminium and their suitability for infants has been questioned.
A number of different brands of soya milk may be purchased. These may
be sweetened or unsweetened and vary in flavour. Market leaders are Provamel,
Granose and Plamil. Some supermarkets also sell own-brand soya milk.
In addition to soya milk, a range of flavoured soya desert and soya yoghurt
products are available.
Other Soya Products
Soya oil and margarine are widely used and are high
in polyunsaturated fats and low in saturated fats. Other less easily available
soya foods
include soya sprouts, soya nuts (roasted and seasoned soya beans), natto
(fermented soya beans made with a bacteria, Bacillus subtilis), yuba (the
skin formed on heated soya milk), soya flakes, soya flour, and high protein
soya isolates and concentrates.
Mycoprotein
Mycoprotein is a food made by continuous
fermentation of the fungus, Fusarium gramineurum. The fungus is grown in
a large fermentation tower to which oxygen, nitrogen, glucose, minerals,
and vitamins are continually added. After harvesting, the fungus is heat
treated to reduce its RNA content to World Health Organisation recommended
levels before being filtered and drained. The resulting sheet of fungal
mycelia is mixed with free range egg egg albumen which acts a binder. Flavouring
and colouring may also be added. The mycoprotein is then textured to resemble
meat, before being sliced, diced or shredded. Mycoprotein is a source of
protein, fibre, biotin, iron and zinc, and is low in saturated fat.
Mycoprotein was developed by Rank Hovis McDougall, and is marketed under the
name of Quorn by Marlow Foods Ltd (now owned by Premier Foods). A wide range
of Quorn ready meals are available including curries, pies, and casseroles, and
it may also be purchased as chunks, mince, sausages, burgers, fillets etc. Since
January 2005 the entire Quorn range have been approved by the Vegetarian Society
(previously the manufacturers had not been able to source enough free range eggs
to use accross whole product range).
(see Quorn
Recipes)
Wheat Protein
Wheat
protein is derived from wheat gluten. It is sometimes called Seitan.
Gluten is extracted from wheat and then processed to resemble
meat.
Wheat protein is marketed under the name of Wheatpro by Lucas Ingredients
of Bristol. It has a greater similarity to meat than textured vegetable
protein or mycoprotein and is used as a meat substitute in a range
of foods. It is available in some health food stores.
Further Information SoyaFoods, 27a Santos Road, London, SW18 1NT. SoyaFoods is
the newsletter published by the American Soybean Association, 20-22
Rue du Commerce, 1040 Brussels, Belgium.
The
Soya Milk Information Bureau, (run by Provamel) PO Box
169, Banbury, Oxon, 0X16 9XE. Tel: 01295 277777 - We are now in a position
to accept requests for general information with regard to Soya Milk
at our email address provamel@vdmuk-rs.co.uk
British
Soya Milk Advisory Service, (run by Plamil) Bowles
Well Gardens, Dover Road, Folkestone, Kent, CT19 6PQ
www.mycoprotein.org -
a website with information, news, research details etc for the public
and health professionals
The Classified Advertising Directory -
for all commercial products and services related to vegetarianism.
Meat Substitutes
More about textured
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