Published: 09/02/2005 - Updated: 08/14/2019
Author: Dra. Loredana Lunadei
Soybean or soy plant is the seed of the leguminous soybean plant. Soybeans and derivatives have been widely used in the Chinese diet for over 4000 years but have only begun to be widely consumed in Western countries since the 1960s. Some derivatives of soy are tofu, tempeh, textured vegetable protein (TVP), miso, sauces, soya oil, margarine and different alternatives to dairy products.
It is an excellent source of high quality protein, has a low content of saturated fat and no cholesterol. Recent studies have indicated that the soybean, in addition to its nutritional value, has several health benefits. It contains high concentrations of several components of known anticancer activity. Among these are the isoflavones, protease inhibitors and phytic acid. The low incidence of breast and colon cancer in China and Japan has been attributed in part to high consumption of soy products. The low incidence of menopausal symptoms in Japanese women has also been linked with the consumption of it. Diets containing soy and derivatives have been found 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 texture similar to that of meat. Before grinding, the flour has been removed from the husk of grains and oil containing was extracted. Once this has been done, the flour is mixed with water to remove soluble carbohydrates and the rest are textured by a process of 'spinning' or extrusion. In the latter the remains of soybeans are heated and move from one area to another high pressure to low pressure through a tube, making the protein from soy is spreading. Then soy protein is dehydrated and in some cases cut into small pieces as if it were beef. You can buy with or without added flavor. Its preparation is simple just mixing it with water or broth and leave to soak for a few minutes and then incorporating into recipes as a substitute for meat. In other products such as vegetarian burgers, sausages, etc. also we found soy protein. Besides being a good source of fiber and high-quality protein, textured vegetable protein is usually fortified with vitamin B12.
Tofu is the curd of soybeans made from coagulated soy milk. To begin, soybeans are soaked, ground and heated to produce soy milk to which was added a coagulating agent such as calcium sulphate or calcium chloride. The resulting soy curd is pressed and leads to tofu. It's sometimes sold in blocks and wrapped in water. You can buy soft (silky), which has a smooth texture and creamy or firm and dense versions. The type of firm tofu can also be smoked or marinated. Tofu tends to have a fairly mild flavor and is why your taste is more successful when used in recipes where other ingredients provide more flavor. The firm tofu can be fried, sautéed, diced and added to salads or stews. Silken tofu can be used to prepare sauces, pates and desserts. In addition to its high protein content, it also contains calcium, iron and vitamins B1, B2 and B3.
The tempeh is a paste of fermented soybeans that is made by inoculating a type of fungus called Rhizopus oligosporous to the cooked soybeans. This fungus forms a mycelium that keeps together the soybeans and is responsible for those black spots that are in tempeh. Texture has a 'tough' and a very peculiar taste. It can replace meat in recipes that require it. You can fry, prepare baked or steamed.
The miso is a fermented condiment made from soya beans, cereals (rice or barley), salt and water. To make miso steamed rice is inoculated with a fungus called Aspergillus oryzae and allowed to ferment to create a product called koji. After, the koji is mixed with soybeans which have previously been heated and extruded with water and salt causing threads. All that is left to ferment in large vats. The flavor, color, texture and aroma of miso varies greatly and depends on its origin and development. Used to flavor soups, stews and sauces.
The original soy sauce, called shoyu, is made by fermenting soybeans with roasted wheat party, water and salt. The Tamari is similar but has a slightly stronger flavor and is made without wheat (and therefore gluten-free). Fermentation of Tamari and shoyu is more or less a year. Most of the soy sauce found in conventional supermarkets is not real soy sauce but is made by chemical hydrolysis from defatted soy flour, caramel coloring and corn syrup without any fermentation process.
Alternative soy milk
Soymilk presents a good alternative to cow's milk and is available in most supermarkets as well as expertise in conventional organic and natural products. Soymilk is produced (as conventional), submerging the soybeans in water and thereafter straining to extract the fiber. Also soy milk can be obtained from isolated soy protein or soy flour. Compared to cow's milk, soy milk contains less fat in it and a smaller proportion of saturated fat and no cholesterol. It is low in carbohydrates and is a good source of protein. Some brands are fortified with calcium, vitamin D2, vitamin B12 and vitamin B2. Soymilk is a good alternative to cow's milk for people suffering from lactose intolerance or milk protein from cows. Allergy to cows' milk is common among the smallest and that is why there is soy milk specially formulated for babies.
The media has been emphasizing the high aluminum content of the soymilk. However it is lower than that of cow's milk and is in the acceptable limits set by the World Health Organization. It has been found that some infant formulas (both cow's milk such as soy milk) produced concentrates containing high levels of aluminum and its use for feeding babies has challenged.
There are many brands of soy milk on the market. They may have sugar added or not and are presented with different flavors. The market leaders are Provamel and Plamil. Some supermarkets have their own brand of soy milk. In addition to milk, there are also other soy desserts and yogurt.
Other products derived from soybeans
The soy oil and margarine are widely used and have a high content of polyunsaturated fats and low in saturated fat. There are other types of foods derived from soybeans that are not so easily to find such as soybean sprouts, soy nuts (roasted soybeans and seasoned), the natto (fermented soybeans made with the aid of bacteria Bacillus subtilis), the Yuba (the 'skin' that is formed to heat soy milk), soy flakes, soy flour and soy protein isolated and concentrated.
The protein of wheat comes from wheat gluten. Also known as seitan. The wheat gluten is extracted and then processed to achieve a texture similar to that of meat. The protein of wheat is marketed under the name 'Wheatpro' by Lucas Ingredients Bristol. Its texture is similar to the meat of the textured vegetable protein or micoprotein and used as a substitute for meat in many foods. Available in natural products stores.
Source: The Vegetarian Society UK
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