Soya & Mycoprotein
Soya:- Textured Vegetable Protein
-- Tofu -- Tempeh -- Miso
-- Soya Sauces -- Soya Dairy Alternatives
-- Other Soya Products
Mycoprotein -- Wheat Protein
-- Further Information
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).
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
- Soya Information Service, PO Box 4, Stourbridge, West Midlands,
DY9 8DQ.
- 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
- Vegetable Protein Association, Food & Drink Federation, 6 Catherine
Street, London, WC2B 5JJ.
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