Table of content A-Z


soya bean


Synonym: soybean

botanical name: Glycine max



The soya bean is the most important legume grown worldwide and in international commerce.


It stems originally from East or Southeast Asia, where it has been grown as a crop plant and made into many staple foods for several thousand years. The name probably derives from the Chinese word sou, which means something like "large bean". In the Chinese diet the soya bean is on a level with the grain varieties wheat, barley, millet and rice.


In the 18th century, this bean reached first Europe and later North America. However, it was not until the 20th century that it became an important business crop worldwide. The soya bean thrives especially in warm climate zones, but also in warmer areas of temperate regions, and is cultivated today in almost all countries of the world.


With 50% of the total harvest, the USA is today the largest producer of soya beans, followed by Brazil, China, Argentina, India and Italy, whereby China's production is largely for its own requirements.




The domestic market supplies practically no fresh beans. As a rule, only dried soya beans are used by us for preparing foods; chiefly the yellow varieties are sold. These are available throughout the year.


The consumption of whole beans plays a minor role here in Germany. Instead, a large number of processed foods are imported from around the world and can also be bought year round.


Appearance, taste, characteristics


The soya bean is similar in appearance to the dwarf bean. The oblong pods covered with fuzz usually contain two to three hard, round, flat, convex, egg- or kidney-shaped seeds.


The colour can differ according to the variety, from yellow to olive-yellow or -green, to brown or purple to black.


The so-called mass of 1000 grains states how much 1000 seeds of a fruit weigh. With the soya bean this can lie between 50 and 450 g, which makes clear how different in size the seeds of the different varieties can be. Light-coloured, large seeds are generally preferred commercially.


The large number of soya bean varieties can be grouped into three types:

* early-maturing varieties (with a vegetation period of 85-95 days)

* medium varieties (95-110 days)

* late-maturing varieties (110-125 days)




In contrast to other legumes, soya beans, particularly the yellow-skinned varieties, are rich in fat and-with a fat content of about 20%-belong to the oil-supplying fruits. Their fat composition is characterized by a high content of polyunsaturated fatty acids (above all linoleic acid).


They are especially rich in high-quality protein. With a protein content of over 30% they occupy a top position among the already very protein-rich legumes. Moreover, the quality, i.e. the biological value, of the protein in soya beans is relatively high.


In addition to these nutrients soya beans contain considerable amounts of fibre, which provides for healthy intestinal activity.


Soya beans contain numerous vitamins, minerals and trace elements. They have appreciable amounts of vitamins B1 and B2, vitamin E and folic acid, as well as the minerals magnesium, calcium, potassium and iron. Since this is non-haem iron from a vegetable source, it is recommended that the beans be combined with foods rich in vitamin C in order to enhance the bioavailability of the iron.


Also worthy of mention is their content of secondary plant substances, above all phytoestrogens, phytosterines and protease inhibitors.


On the whole, soya beans have a very high nutritional value.


100 g contain:


Soya bean, dried

Soya bean, cooked

Soya bean, roasted

Energy (kcal)




Water (g)




Protein (g)




Fat (g)




Carbohydrates (g)




Fibre (g)




Vitamin A (RE) (µg)




Vitamin E (mg)




Vitamin B1 (mg)




Vitamin B2 (mg)




Niacin (mg)




Vitamin B6 (mg)




Folic acid (µg)




Vitamin C (mg)




Potassium (mg)




Sodium (mg)




Calcium (mg)




Magnesium (mg)




Phosphorus (mg)




Iron (mg)





The nutrient content can be influenced by soil and climate conditions and by characteristics of the individual variety.


Quality criteria, optimal storage conditions


Soya beans should be intact and not broken; small circular holes are signs of destruction by pests during storage.


In a cool, dry place soya beans will keep for 1-2 years.


Form of consumption, use, processing, practical tips for preparation


This legume has manifold uses. Whole soya beans, however, are difficult to digest and raw they are even inedible.


The soya bean is principally a dried fruit. In the producing countries unripe soya beans are also sometimes cooked with or without the pods and eaten like fresh beans or peas as a vegetable or used as a preserved food.


Dried soya beans are processed like other pulses. Tips for preparation can be found in the chapter on legumes and pulses. Cooked, the beans are popular in soups, salads or as a vegetable dish.


They are suitable for stews since they remain firm even after being cooked and lend a light flavour of filberts or hazelnuts to dishes.


Finely ground soya beans cook much more quickly than whole beans; however, they require a larger amount of water. Ground soya beans also have many uses and give soups, stews, sauces, baked goods and bread a spicy flavour.


Soya beans that are dried or ground into flour can also be used in many dishes. Soya flour is gluten-free. Gluten is a protein found chiefly in wheat, to which some people react allergically (coeliac disease, gluten-induced/gluten-sensitive enteropathy). As soya flour doesn't rise during baking, it is usually mixed with wheat flour. Because it doesn't keep well due to its high fat content, reduced-fat flour is sold. In any case, soya flour that is not fat-reduced must be stored in the refrigerator.


A coffee substitute is also made from roasted and ground soya beans. This can be brewed like coffee and tastes similar to it.


The commonly sold "soybean sprouts" are usually not sprouts of the soya bean but are grown from mung beans. However, sprouts can also be grown from soya beans. They are nutritious and aromatic and can be used cooked briefly or raw. Further information can be found in the chapter on sprouts.


Because of their favourable composition, with high contents of protein and fat, soya beans are particularly suited for further processing. The multitude of products ranges from soya flakes, grits, granules, lecithin, oil, milk, curd, and fermented items to "soya meat". Via these intermediate products, soya is contained, for example, in cocoa powder, biscuits, chocolate bars, nut-nougat creams, and numerous other foods.


In the region of Southeast Asia soya products have a long tradition. Some of them are briefly presented here.


Products made from the soya bean:

Soybean oil

Refined soybean oil is light yellow, neutral in flavour, and is suitable for braising and frying. It is also used to make margarine, mayonnaise, rémoulade/tartar sauce, dressings, baked goods and sweets, etc. Soybean oil is used not only as a cooking oil but also for technical purposes. The soybean pomace is used as a protein-rich animal feed.


Soya milk / soya drink

In the food-regulatory sense, of course, soya milk is not milk but a watery extract from soya beans. From the finely ground seeds and water a drink with a mild, sweetish taste is produced with the use of steam. It contains no milk protein and is therefore a popular milk substitute for persons with an allergy to milk protein. It is also suitable for persons who cannot digest lactose (milk sugar) because soya drink contains no lactose.


However, soya milk contains considerably less calcium than cow's milk, and to compensate for this deficiency some producers offer soya milk enriched with calcium. Strawberry-, chocolate- and vanilla-flavoured drinks are also sold, and coffee creamers and desserts are made from soya beans.



In the Asian region, tofu is a popular, versatile food that has become increasingly important in the USA and Europe as well over the past few years. Tofu is a cheese-like product with approximately 8% protein and 5% fat and is used by many vegetarians as a substitute for meat.


To make tofu, soya milk is turned into a curd-like mass using a coagulant; then the excess liquid is pressed out. Tofu is white-yellow, gelatinous and firm, and is usually sold in blocks. It has almost no flavour of its own and can therefore be combined with many ingredients; it takes on other flavours.

Many products based on tofu are meanwhile on the European market that conform to our taste and eating habits. In addition to tofu with vegetables and smoked tofu, there are seasoned spreads and substitutes for mayonnaise, sausage, cold cuts and ice cream.


Natto, sufu

Natto (from Japan) and sufu (from China) are creamy, cheese-like products with a large amount of salt that are eaten as spicy accompaniments to vegetables and meat. They also are sometimes called fuju, fuyu, toufuju, furu, toufuru, tosufu and fusu. They are made from fermented tofu. In the production, tofu is inoculated with special mould cultures which cause a thick network of mould to form. Thereafter it ripens for several weeks in brine. It is sold in various flavours that are produced by adding, for instance, rice wine or rose oil.



Tempeh is a firm, ripened soya-bean mass that is sliced and eaten roasted or cooked like meat. In contrast to tofu, tempeh has a strong characteristic flavour resembling that of blue cheese.


It is made of cooked soya beans that are inoculated with mould cultures and ripened for several days. During this time a compact mass forms that not only adheres to the surface but permeates the entire product. Fresh tempeh is mottled grey or black and keeps for only a short time.


Therefore, it is usually sold deep-frozen, dried or pasteurized. It can be found in Asian food shops and health-food shops.


Soya sauce

Soya sauce is a thick, brown, savoury-salty table seasoning that is popular not only in Asia but meanwhile throughout the world. It plays a special role in Chinese and Japanese cuisine. Soya sauce is made by fermentation of soya beans, wheat or rice and, like wine, requires a certain time to age.


Owing to its high salt content of 17-19% it keeps for a long time without refrigeration, and it is an ingredient in many other sauces such as barbecue or Worcestershire sauce.


In general, soya beans and some wheat or rice are used to make soya sauce. The ingredients are chopped, soaked, heated and inoculated with mould cultures. After some days, salt is added, and an ageing process follows with the help of special lactic-acid bacteria and yeasts; traditionally, this lasts for several months up to 2 years. Finally, the liquid is pressed out and pasteurized.


The traditional ageing time for soya sauce is markedly shortened in some cases. The missing natural ageing is compensated for by the addition of aromatic and colouring substances.


Frequently, whole soya beans are no longer the base product but fat-reduced soya flour that is obtained in the extraction of soybean oil.


There are several different types of soya sauce:

Shoyu is made from soaked, cooked soya beans and roasted, crushed wheat grain. Tamari was originally a by-product of miso production. Today, this wheat-free soya sauce is also manufactured separately. Owing to its exceptionally strong flavour, it is better suited to use in cooking than at the table.



In Japan there are a large number of miso varieties. Miso is one of the most important soya products there. It is a yellow, orange or brown aromatic paste used to season sauces, stews, and vegetable, fish and meat dishes. Like bouillon cubes it frequently serves as the basis for soups.

Miso is made from soya beans and some type of grain. Similar to soya sauce, various micro-organisms are used in addition to salt to ferment the product; then the miso ages by means of fermentation for up to 2 years. During this time many aromas, colours and flavours develop.

Miso is sold in delicatessen departments and in Asian and natural-food stops.


Soya sausage

This vegetarian sausage substitute is made from tofu or soya flour. By adding fat, seasonings and binding agents it is possible to imitate many varieties of meat sausage. There are sausages to cook, fry, or grill or to be used in a sandwich.


Soya meat / textured vegetable protein (TVP)

This is a highly processed finished product made from soya beans that can be used as a substitute for meat. The flavour and the fibrous texture of prepared TVP resemble those of animal meat.


There are two different methods for making soya meat:

With the first method, a protein concentrate is obtained from fat-reduced soya flour. Usually, crushed soya is used that remains after oil is extracted. This protein is then spun into a protein strand, enriched with flavour and colouring, and formed into meat-like fibres. The second method uses soya flour as the basis and obtains the desired structure of the TVP by means of water vapour pressure.


According to how it is cut, the result is soya protein resembling ground meat or meat cubes. TVP can be bought prepared or dried in the health-food shop. It has many uses, e.g. in soups, sauces, as burgers or in the form of goulash.




In China the soya bean is one of five holy plants that in earlier times were also sown by the emperor himself.





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