Sybean milk preparation

The soybean is a species of legume, widely grown for its edible bean which has numerous uses. The plant is classed as an oilseed rather than a pulse. Soybean is a complete reservoir of nutrients, especially, proteins. It is the phytochemicals in soybean that prevents blood clotting from taking place. It aids in protecting the heart against oxidation. Soybean serves as an excellent source of essential fatty acids, calcium, magnesium, lecithin, fiber, folate, iron etc. Proteins in soybean can be food substitutes for animal products because unlike some other beans, say often a complete profile. Soy proteins can replace animal food based nutrients [proteins]. In other words, soy protein is the nutritional equivalent of meat, egg and casein for human body.

ORIGIN
The oldest evidence of soymilk production is from china where a kitchen scene proving use of soy milk is incised on a stone slab dated around AD 25-220. It also appeared in a chapter called Four Taboos (Szu-Hui) in the AD 82 book called Lunheng by Wang Chong, possibly the first written record of soymilk. Evidence of soymilk is rare to the 20th century and widespread usage before then is unlikely. According to popular tradition in china, soy milk was developed by Liu An for medical purposes, although there is no historical evidence for his legend . This legend first appeared in the 12th century and was not clearly stated until late 15th century in Bencao Gangmu where the development of tofu was attributed to Liu with no mention of soy milk. Later writers in Asia and the west additionally attributed development of soy milk to Liu An, assuming that he could not have made tofu without making soy milk. This may be incorrect. In addition, some recent writers claim Liu An developed tofu in 164 BC

Soy milk
Soy milk is a beverage made from soybeans. It is a stable emulsion of oil water and protein. It is produced by soaking dry soybeans and grinding them with water. Soymilk contains about the same proportion of protein as cow’s milk. Soymilk can be made at home with traditional kitchen tools or with a soy milk machine the coagulated protein from soy milk can be made into tofu (bean curd), just as a dairy milk can be made into cheese Soy milk is most commonly found in aseptic cartons. Most of the soya milk available in the marked is flavored and fortified with extra calcium or vitamins. Traditionally, soy milk has a beany taste. Recently, with the recognition of its health benefits and with its improved flavor and texture, soy milk has now a high and rising acceptance. Soy milk, with complete proteins of soybean, can be good substitute for animal products for animal products. It is because it offers a complete protein profile. Such a kind of soy milk can replace animal based foods without requiring major adjustments elsewhere in the diet.

Plain soy milk is very nutritive. It’s an excellent source of high quality proteins, isoflavones and B-vitamins. Soy milk is free of the milk sugar and it’s a good choice for people who are lactose intolerant. Also, it is good alternative to those who are allergic to the proteins of cow’s milk. In other words, pure soy milk-with complete soy protein- is the nutritional equivalent of meat, eggs and casein for human growth and health. Preparation of soy milk Soy milk can be made from whole soybeans or full fat soy flour. The dry beans are soaked in water overnight or for a minimum of 3 hours or more depending on the temperature of water. The rehydrated beans then undergo wet grinding with enough added water to give the desired solids content to the final product. The ratio of water to bean on a weight basis should be about 10:1. The resulting slurry is brought to boil in order to improve its nutritional value by heat in activating soybean trypsin inhibitor, improve its flavor and to sterilize the product. Heating at or near boiling point is continued for a period of time 15-20 followed by the removal of insoluble filtration. For all raw soybean protein products, heat is necessary to destroy the activity of protease inhibitors naturally present in the soybean. The pancreas naturally secretes proteases to digest a protein meal. Eating a raw soybean on a regular basis causes the pancreas to hyper secrete, leading to benign tumor of the pancreas. When soybeans absorb water, the endogenous enzyme, Lipoxygenase (LOX), EC1.13.11.12 linoleate: oxireductase, catalyzes a reaction between polysaturated fatty acids and oxygen. LOX initiates the formation of free radicals, which can then attack other cell components. Soybean seeds are richest known sources of LOXs. It is thought to be a defensive mechanism by the soybean against fungal invasion. In 1967 experiment at Cornell University at Geneva, NY, led to the discovery that point like, off flavours of traditional soy milk can be prevented from forming by rapid hydration grinding process of dehulled beans at temperature above 80 degree Celsius.

The quick moist treatment inactivates the LOX enzyme before it can have a significant negative effect on flavor. The beany flavor in soybean was not inherent in beans themselves, it is also produced by enzyme lipoxygenase. Normal mature soybeans actually contains three LOX isozymes (SBL-1, SBL-2, SBL-3) important for undesirable flavor development. One or more of these isozymes have recently been removed genetically from soybeans yielding soy milk with less cooked beany aroma and flavour and less astringency. Lipoxygenase could be inactivated and most of the beany flavor removed by either dropping unsoaked soybeans directly into boiling water or by removing any cracked or split been prior to soaking, then carefully dropping the soaked beans into boiling water.

COMPARISON BETWEEN SOY AND NATURAL MILK
The major difference between soy milk and regular milk (predominantly cow’s milk in the United States, goat and sheep milk is other options) is that one is desired from a plant and the other from an animal. Although ethical, hypothetical or debatable issues frequently arise when discussing this subject, this answer is going to deal strictly with the nutritional differences between these two kinds of milk. Soy milk has the same amount of protein as cow’s milk, though the amino acid profile differs. What’s most commonly referred to as simply cow’s milk, a product of the cow’s mammary gland. As with all other animal based foods, it is a complete protein; that is it supplies people with all necessary amino acids to form proteins. Cow’s milk contains 8gm of protein and 12gm of carbohydrate per 8-ounce cup. Cow’s milk is a rich source of other nutrients as well. One cup provides adults with about 30 percentage of their daily calcium needs and about 50 percentage of their vitamin B12 and riboflavin requirements. Often milk is fortified with vitamin D to facilitate the absorption of calcium. Vitamin A is usually added to milk as well. Depending on the selection, cow’s can have a significant amount of food.

Lactose, the primary carbohydrate and cow’s milk poses a digestive problem for some people for some people. These folks are deficient in their lactase enzyme that is needed to break down this milk sugar, causing gas, bloating and diarrhea after consuming some form of dairy products. The solution is to purchase products with lactose already broken down to take the enzyme in the form of pills or drops or to find a substitute for these foods. Soy milk is not technically milk, but a beverage made from soybeans. It is the liquid that remains after soybeans are soaked, finely ground and then strained. Since it doesn’t contain any lactose soymilk is suitable for lactose intolerant folks. It is also a popular cow’s milk substitutes for vegans and vegetarians since it is based on the plant source (others include rice, oats, almond, coconut and potato milk). One cup of unfortified soy milk contains almost7 grams of proteins, 4 grams of carbohydrate, 4.5 gram of fat and no cholesterol. Although soy milk supplies some B vitamins, it is not a good source of B12 or does not provide a significant amount of calcium. Natural soy milk contains little digestible calcium as it is bound of bean’s pulp, which is indigestible by humans. Since many people substitute soy

beverages for cow’s milk, manufacturers offer fortified versions. These varieties may include calcium and vitamin E, B12 and D among other nutrients. Soy products contain sucrose as the basic disaccharide, which breaks down into glucose and fructose. Since soy doesn’t contain galactose, a product of lactose breakdown, soy-based infact formulas can safely replace breast milk in children with galactosemia. Soy milk may help some people reduce their risk for heart diseases. Soy naturally contains isoflavones, plant chemicals that help lower LDL (bad cholesterol) if taken as part of a “heart healthy” plan. The recommendation is to take in about 25 grams of soy protein per day. One cup of soy milk has about 7-10 grams of proteins depending upon the brand. Previously researchers thought soy consumption was correlated with increased rates of breast cancer, but recent research suggest that soy milk consumption may actually reduce breast cancer rates for some populations including past-menopausal women and Asian populations. Soy’s unique effect on Asian women is thought to be the result of larger amount of dietary soy consumed over longer periods of time than other in women.

Advantages and Disadvantages

Advantages:
*The Soy Food Association of North American states, scientists have found that consumption of soy proteins can contribute to reducing the risk of heart diseases. *Soy milk’s nutritional highlights include containing a host of essential fatty acids, being a high quality protein source, having no cholesterol and having very little saturated fat. In addition, soy milk is a good source of vitamin A, B, D, fiber, iron and potassium. *It has been suggested that women who regularly consume soy roducts are less likely to develop breast cancer according to studies such as at the National Medical Research Council Clinical Trials and Epidemiology Research unit in Singapore.

*Soy milk contains a large amount of phytochemicals, including isoflavones, genistein and diadzein. The Lomo Linda University in California, Department of Nutrition, has produced evidence that isoflavones help prevent osteoporosis. *Soy milk contains no milk sugar therefore it is a good dairy substitute for those who are lactose intolerant, which affects between 30 to50 million people of the world’s population according to the U.S Department of Health and Services. *Cow’s milk provokes allergy symptoms in some people, which is different than lactose intolerance. According to the children, Youth and Women’s Health Service in Australia, approximately one in 50 infants is allergic to cow’s milk. Although most children grow out of the allergy by age 4, the allergic infant’s immune system is unable to recognize milk proteins and therefore reacts adversely in the form of skin rashes and breathing problems. Soy milk can provide the nutrients and vitamins found in cow’s milk.

DISADVANTAGES:
*soy milk and soy based products have been theorized to be harmful is a person’s health if consumed in large quantities. Speculation has been raised because soy products contain larger amounts of certain nutrients than found in other plants and soy products also increase the human body’s need for certain vitamins. There is no scientific evidence to support these claims. *It is highly processed. The traditional home based preparation of soy milk involves multiple skimming and staining to remove impurities. A note has been made that industrial methods for producing soy milk, do not strain out impurities, but heat the milk to extremely high temperature to destroy any “anti-nutrients”. The pasteurization process destroys some of the amino acids and makes the protein in soy milk hard to digest. Most soy milk brands contain preservatives and thickeners. *Soy plants are treated usually heavily with pesticides and herbicides. Soy not labeled `organic` is most likely genetically engineered. The health impacts of consuming genetically engineered food are uncertain, but if you want to avoid them as a precaution, make sure you choose only organic soy milk *Many types of soy milk contain added sweetness such ad a corn syrup, evaporated cane juice or rice syrup. These sugars increase the calorie content of the soy milk and contribute to an American diet high in added sugar. The American Heart Association note that Americans eat an average of 22.5 tsp of added sugar daily and is not fair for an Indian to have such amount (and) as the living situations are different and varies greatly. *Soy proteins may affect your ability absorb the thyroid medications and thus can cause thyroid complications. Consuming too much soy in combination with too little iodine may interfere with normal thyroid functions. *Oxalates are a naturally occurring compound found in many foods. Consuming too many oxalates may cause kidney stone. Soy milk has a high amount of oxalates and their intake causes the same.

Ecological Impacts
Using soybeans to make milk instead of raising cows may be ecologically advantageous, because the amount of soy that could be grown using the same amount of land would feed more people than if used to raise cows. Cows require much more energy in order to produce milk, since the farmer must feed the animal, which can consume up to 24 kilogram (53 pound) of food in dry matter (DM) basis and 90 to 180 litres (25 to 50 gallons) of water a day, producing an average of 40 kilograms of milk a day. Because the soybean plant is a legume, it also replenishes the nitrogen content of the soil in which it is grown. In Brazil the explosion of soybean cultivation has led to losing large tracts of forest land leading to ecological damage. These particular cleared forests are planted with soy intended for animal agricultural enterprises (especially beef and pork production) not for human consumption. The American soil scientist Dr Andrew McClung was the first to device a method to grow soybeans in the 2006 World Food Prize.

BENEFITS OF SOY MILK
1: Soy milk contains only vegetable proteins.
Vegetable proteins have advantage that they cause less loss of calcium through the kidney. 2: Soy milk contains no lactose. About 75% of the world population cannot tolerate lactose. As an additional benefit, soy milk contains the prebiotic sugars stachyose and raffinose. These sugars boost immunity and help decrease toxic substances in the body. 3: Soy milk reduces cholesterol.

The protein in cow’s milk has no benefit for the cholesterol. Soy proteins can decrease cholesterol level. The FDA confirms that soy proteins, as a part of diet low in saturated fat and cholesterol may significantly reduce the risk of coronary heart. 4: Soya milk contains no hormones.

Cow’s milk contains natural and synthetic hormones. But soy milk is free of any hormones

5: Soy milk does not cause insulin dependent diabetes.
6: Soy milk is rich in isoflavones.
7: Fewer people are allergic to soya milk.

OTHER SOY FOOD PRODUCTS
TOFU:
Tofu is likely the most well-known soy products, and comes in a variety of forms. Silken tofu has a creamy consistency and can be used with salad dressings and as a replacement for sour cream; firm tofu is solid and can be cubed or cut up and soft tofu is softer than firm tofu but is not like silken tofu. Tofu is also called soybean curd, and it absorbs the flavor of food which it is cooked, say the U.S soy foods Directory. Nutritionally, tofu is high in protein and B vitamins with firm tofu containing the most nutrients. TEMPEH:

Tempeh, a traditional Indonesian food, is commonly used as a meat substitute and is made from fermented soybeans. It has a firmer texture to it than tofu and a nutly mushroom taste, according to Tempeh info, and can be combined with grains like rice or millets. Temph contains isoflavones, is high in protein and contains all the essential amino acids, as well as fiber. These nutrients can help strengthen bones and aid in digestive health.

SOYBEAN CURD:
Also called `miso`, soybean curd is prepared from soybean milk by adding vinegar, lemon juice or calcium chloride. In some countries the curd is allowed to ferment naturally in a warm place which results in a different soybean curd. By itself the soybean curd has no taste but it is used in soups, salads, omelets etc.

SOYBEAN OIL:
When considering edible uses of soybean, soy oil tops the list. Products that contain soy oil include prepared dressings, margarine and salads and cooking oils. Soy oils has a bland taste and a high smoking point and therefore it is recommended for frying. OKARA:

Okara is the residual fibers after extraction of milk from soybean. It contains about 80% moisture and can be dried by drying system to get dried product with 4%-12% moisture content. The dried okara can be used as a source of good fiber and can be used in making biscuits, sweets etc.

SOY SAUCE:
Soy sauce is produced by the fermented soybeans, according to U.S Soy foods Directory. There are three different kinds of soy sauce; shoyer, tamari and tiriyaki. Shoyer sauce is made from soybeans and wheat, tamari sauce is made solely by soybeans and teriyaki sauce is made with sugar, vinegar and other ingredients. Although they have a salty taste, soy sauces contain less sodium than typical table salt. SOYBEAN SPROUTS:

Soybeans like chickpeas and mung beans, can be used for sprouts, either grown at home or commercially. Sprouts can be blanched and kept refrigerated for use in soups, salads, vegetables and chicken casseroles.