Fat-free (defatted) soybean meal is a primary, low-cost, source of protein for animal feeds and most prepackaged meals soy vegetable oil is another product of processing the soybean crop. For example, soybean products such as textured vegetable protein (TVP) are ingredients in many meat and dairy analogues. Soybeans produce significantly more protein per acre than most other uses of land.
Like some other crops of long domestication, the relationship of the modern soybean to wild-growing species can no longer be traced with any degree of certainty. It is a cultural variety with a very large number of cultivars.
Remarkably, seeds such as soybeans containing very high levels of protein can undergo desiccation yet survive and revive after water absorption. A. Carl Leopold, son of Aldo Leopold, began studying this capability at the Boyce Thompson Institute for Plant Research at Cornell University in the mid 1980s. He found soybeans and corn to have a range of soluble carbohydrates protecting the seed's cell viability. Patents were awarded to him in the early 1990s on techniques for protecting "biological membranes" and proteins in the dry state. Compare to tardigrades.
Together, oil and protein content account for about 60% of dry soybeans by weight; protein at 40% and oil at 20%. The remainder consists of 35% carbohydrate and about 5% ash. Soybean cultivars comprise approximately 8% seed coat or hull, 90% cotyledons and 2% hypocotyl axis or germ.
Most soy protein is a relatively heat-stable storage protein. This heat stability enables soy food products requiring high temperature cooking, such as tofu, soy milk and textured vegetable protein (soy flour) to be made.
The principal soluble carbohydrates of mature soybeans are the disaccharide sucrose (range 2.5–8.2%), the trisaccharide raffinose (0.1–1.0%) composed of one sucrose molecule connected to one molecule of galactose, and the tetrasaccharide stachyose (1.4 to 4.1%) composed of one sucrose connected to two molecules of galactose. While the oligosaccharides raffinose and stachyose protect the viability of the soy bean seed from desiccation (see above section on physical characteristics) they are not digestible sugars and therefore contribute to flatulence and abdominal discomfort in humans and other monogastric animals; compare to the disaccharide trehalose. Undigested oligosaccharides are broken down in the intestine by native microbes producing gases such as carbon dioxide, hydrogen, and methane.
Since soluble soy carbohydrates are found in the whey and are broken down during fermentation, soy concentrate, soy protein isolates, tofu, soy sauce, and sprouted soy beans are without flatus activity. On the other hand, there may be some beneficial effects to ingesting oligosaccharides such as raffinose and stachyose, namely, encouraging indigenous bifidobacteria in the colon against putrefactive bacteria.
The insoluble carbohydrates in soybeans consist of the complex polysaccharides cellulose, hemicellulose, and pectin. The majority of soybean carbohydrates can be classed as belonging to dietary fiber.
For human consumption, soybeans must be cooked with "wet" heat in order to destroy the trypsin inhibitors (serine protease inhibitors). Raw soybeans, including the immature green form, are toxic to humans, swine, chickens, in fact, all monogastric animals.
Soybeans are considered by many agencies to be a source of complete protein. A complete protein is one that contains significant amounts of all the essential amino acids that must be provided to the human body because of the body's inability to synthesize them. For this reason, soy is a good source of protein, amongst many others, for vegetarians and vegans or for people who want to reduce the amount of meat they eat. According to the US Food and Drug Administration:
Soy protein products can be good substitutes for animal products because, unlike some other beans, soy offers a 'complete' protein profile. ... Soy protein products can replace animal-based foods—which also have complete proteins but tend to contain more fat, especially saturated fat—without requiring major adjustments elsewhere in the diet.
Soy protein is essentially identical to that of other legume seeds. Moreover, soybeans can produce at least twice as much protein per acre than any other major vegetable or grain crop besides hemp, 5 to 10 times more protein per acre than land set aside for grazing animals to make milk, and up to 15 times more protein per acre than land set aside for meat production.
Consumption of soy may also reduce the risk of colon cancer, possibly due to the presence of sphingolipids.
Soybeans are an important global crop, providing oil and protein. In the United States, the bulk of the crop is solvent-extracted with hexane, and the "toasted" defatted soymeal (50% protein) then makes possible the raising of farm animals (e.g. chicken, hog, turkey) on an industrial scale never before seen in human history. A very small proportion of the crop is consumed directly by humans. Soybean products do, however, appear in a large variety of processed foods.
Cultivation is successful in climates with hot summers, with optimum growing conditions in mean temperatures of 20 to 30 °C (68 to 86 °F); temperatures of below 20 °C and over 40 °C (68 °F, 104 °F) retard growth significantly. They can grow in a wide range of soils, with optimum growth in moist alluvial soils with a good organic content. Soybeans, like most legumes, perform nitrogen fixation by establishing a symbiotic relationship with the bacterium Bradyrhizobium japonicum (syn. Rhizobium japonicum; Jordan 1982). However, for best results an inoculum of the correct strain of bacteria should be mixed with the soybean (or any legume) seed before planting. Modern crop cultivars generally reach a height of around 1 m (3.3 ft), and take 80–120 days from sowing to harvesting.
The U.S., Brazil, Argentina, China and India are the world's largest soybean producers and represent more than 90% of global soybean production. The U.S. produced 75 million tons of soybeans in 2000, of which more than one-third was exported. In the 2010-2011 production year, this figure is expected to be over 90 million tonnes. Other leading producers are Brazil, Argentina, Paraguay, China, and India.
Environmental groups, such as Greenpeace and the WWF, have reported that soybean cultivation and the probability of increased soybean cultivation in Brazil has destroyed huge areas of Amazon rainforest and is encouraging further deforestation.
Soybean plants are vulnerable to a wide range of bacterial diseases, fungal diseases, viral diseases and parasites.
Further information: List of soybean diseases
Soybeans can be grown organically; that is without the use of synthetic pesticides and fertilizers.
Further information: Organic Beans
Soybeans are one of the "biotech food" crops that have been genetically modified, and genetically modified soybeans are being used in an increasing number of products. In 1995 Monsanto Company introduced Roundup Ready (RR) soybeans that have been genetically modified to be resistant to Monsanto's herbicide Roundup through substitution of the Agrobacterium sp. (strain CP4) gene EPSP (5-enolpyruvyl shikimic acid-3-phosphate) synthase. The substituted version is not sensitive to glyphosate.
The widespread use of such types of GM soybeans in the Americas has caused problems with exports to some regions. GM crops require extensive certification before they can be legally imported into the European Union, where there is considerable supplier and consumer reluctance to use GM products for consumer or animal use. Difficulties with coexistence and subsequent traces of cross-contamination of non-GM stocks have caused shipments to be rejected and have put a premium on non-GM soy.
In 2010, a team of American scientists announced they had decoded the genome of the soybean - the first legume to be sequenced.
Approximately 85% of the world's soybean crop is processed into soybean meal and vegetable oil. Soybeans can be broadly classified as "vegetable" (garden) or field (oil) types. Vegetable types cook more easily, have a mild nutty flavor, better texture, are larger in size, higher in protein, and lower in oil than field types. Tofu and soy milk producers prefer the higher protein cultivars bred from vegetable soybeans originally brought to the United States in the late 1930s. The "garden" cultivars are generally not suitable for mechanical combine harvesting because there is a tendency for the pods to shatter upon reaching maturity.
Among the legumes, the soybean, also classed as an oilseed, is pre-eminent for its high (38–45%) protein content as well as its high (20%) oil content. Soybeans are the second most valuable agricultural export in the United States behind corn. The bulk of the soybean crop is grown for oil production, with the high-protein defatted and "toasted" soy meal used as livestock feed. A smaller percentage of soybeans are used directly for human consumption.
Immature soybeans may be boiled whole in their green pod and served with salt, under the Japanese name edamame (edamame?). In English, these soybeans are generally known as "edamame" or "green vegetable soybeans."
The beans can be processed in a variety of ways. Common forms of soy (or soya) include soy meal, soy flour, soy milk, tofu, textured vegetable protein (TVP, which is made into a wide variety of vegetarian foods, some of them intended to imitate meat), tempeh, soy lecithin and soybean oil. Soybeans are also the primary ingredient involved in the production of soy sauce (or shoyu).
Soybean seed contains about 19% oil. To extract soybean oil from seed, the soybeans are cracked, adjusted for moisture content, rolled into flakes and solvent-extracted with commercial hexane. The oil is then refined, blended for different applications, and sometimes hydrogenated. Soybean oils, both liquid and partially hydrogenated, are exported abroad, sold as "vegetable oil," or end up in a wide variety of processed foods. The remaining soybean meal is used mainly as animal feed.
Allergy to soy is common, and the food is listed with other foods that commonly cause allergy, such as milk, eggs, peanuts, tree nuts, shellfish. The problem has been reported among younger children and the diagnosis of soy allergy is often based on symptoms reported by parents and/or results of skin tests or blood tests for allergy. Only a few reported studies have attempted to confirm allergy to soy by direct challenge with the food under controlled conditions. It is very difficult to give a reliable estimate of the true prevalence of soy allergy in the general population. To the extent that it does exist, soy allergy may cause cases of urticaria and angioedema, usually within minutes to hours of ingestion. In rare cases, true anaphylaxis may also occur. The reason for the discrepancy is likely that soy proteins, the causative factor in allergy, are far less potent at triggering allergy symptoms than the proteins of peanut and shellfish. An allergy test that is positive demonstrates that the immune system has formed IgE antibodies to soy proteins. However, this is only a factor when soy proteins reach the blood without being digested, in sufficient quantities to reach a threshold to provoke actual symptoms.
Soy can also trigger symptoms via food intolerance, a situation where no allergic mechanism can be proven. One scenario is seen in very young infants who have vomiting and diarrhoea when fed soy-based formula, which resolves when the formula is withdrawn. Older infants can suffer a more severe disorder with vomiting, diarrhoea that may be bloody, anemia, weight loss and failure to thrive. The most common cause of this unusual disorder is a sensitivity to cow's milk, but soy formulas can also be the trigger. The precise mechanism is unclear and it could be immunologic, although not through the IgE-type antibodies that have the leading role in urticaria and anaphylaxis. Fortunately it is also self-limiting and will often disappear in the toddler years.
Soybeans famous for its rich nutritional value and is one food that contains 8 essential amino acids needed by human body.
Unlike other foods that contain adequate saturated fat and can not digest found in most pet food, soy beans contain no cholesterol, has a low ratio of calories than protein and acts as a fattening food for people who are not obese.
Soybeans also contain calcium, iron, potassium and phosphorus. Soybeans are also rich in vitamin B complex. Soybeans is one that contains high protein, high calcium foods, soybean is also unique because it is free from toxic chemicals. While the fatty tissues of animals are known to contain 20 times the weight of steel, insect venom and plant toxins than those found in legumes.
Some of the benefits of Soybean
The best sources of vegetable protein
Strengthens immune system
Stabilizing blood sugar levels
protect the heart
Build strong bones
Lower risk of heart disease
Lowering blood pressure and cholesterol
Preventing menopause for women
Reduce the risk of breast cancer
Reduce the risk of prostate cancer
Reduce the risk of heart attack and stroke
Generate power and improve health
Soybean, mature seeds, raw nutritional value per 100 g (3.5 oz)
Energy : 1,866 kJ (446 kcal)
Carbohydrates : 30.16 g
- Sugars : 7.33 g
- Dietary fiber : 9.3 g
Fat : 19.94 g
- saturated : 2.884 g
- monounsaturated : 4.404 g
- polyunsaturated : 11.255 g
Protein : 36.49 g
- Tryptophan : 0.591 g
- Threonine : 1.766 g
- Isoleucine : 1.971 g
- Leucine : 3.309 g
- Lysine : 2.706 g
- Methionine : 0.547 g
- Cystine : 0.655 g
- Phenylalanine : 2.122 g
- Tyrosine : 1.539 g
- Valine : 2.029 g
- Arginine : 3.153 g
- Histidine : 1.097 g
- Alanine : 1.915 g
- Aspartic acid : 5.112 g
- Glutamic acid : 7.874 g
- Glycine : 1.880 g
- Proline : 2.379 g
- Serine : 2.357 g
Water : 8.54 g
Vitamin A equiv. : 1 μg (0%)
Vitamin B6 : 0.377 mg (29%)
Vitamin B12 : 0 μg (0%)
Vitamin C : 6.0 mg (10%)
Vitamin K : 47 μg (45%)
Calcium : 277 mg (28%)
Iron : 15.70 mg (126%)
Magnesium : 280 mg (76%)
Phosphorus : 704 mg (101%)
Potassium : 1797 mg (38%)
Sodium : 2 mg (0%)
Zinc : 4.89 mg (49%)