Tofu is a high-protein, soy-bean product which originated in the Orient centuries ago. According to history, tofu production was started in China during the Hang dynasty. It was discovered by Lord Lui Anot Huai-nan in about 164 a.c. Lui An was a famous scholar, philosopher, ruler and politician.
In Japanese history, tofu appears to have begun during the eight century. It was probably brought from China by Buddhist monks who were travelling back and forth between the two countries. The evolution of tofu into Japanese culture is thought to have entered through the upper classes, including the Buddhist monks (vegetarians) who probably used tofu as a main staple in their diets.
The five major Kamakura Zen temples each opened Buddhist vegetarian restaurants which included tofu on their menus. The common people apparently learned how to prepare it from the monks. Although indigenous to the Chinese, Japanese and Korean cultures, tofu is quickly breaking those boundaries.
Even though tofu is centuries old, it is fairly recent to the Western world. Benjamin Franklin introduced soybean seed from France that a century later became a major oil seed. The first tofu shops in America began in about 1900. Henry Ford, auto maker, experimented with soymilk in the 1930`s and was producing several hundred gallons of soymilk a day for friends and co-workers.
Until recently, tofu, if known at all, was perceived to be an Oriental dish. Now it is being recognised for its outstanding nutritional values.
The Nutrition of Tofu
Soybeans and soybean products such as tofu can be recognised as a nutrient source for the world.
Pounds Protein Per Acre
Beef Cattle 058
Another important aspect of tofu`s nutrition is its amino acid profile. Tofu by itself is considered an incomplete protein, like all simple protein sources. However in combination with complementary protein sources such as grains or legumes, it becomes a very high quality source of usable protein or NPU (Net Protein Utilization). In the following comparison, amino acid content is expressed as gram/16 grams nitrogen.
Amino Acid Comparison
Amino Acids Soybean Tofu WholeEgg
Isoleucine 4.2 4.9 6.3
Leucine 7.4 8.0 8.8
Lysine 6.4 5.9 7.0
Methionine 1.2 1.4 3.4
Cystine 0.9 1.7 2.4
Phenylalanine 4.5 4.8 5.7
Tyrosine 3.4 3.7 4.2
Total Aromatic 8.0 8.5 9.9
Threonine 3.6 3.7 5.1
Tryptophan 1.7 * 1.5
Valine 4.3 4.7 6.8
The Processing of Tofu
The process of making tofu is relatively simple. The only `difference between the way tofu was made centuries ago and today is that modern machinery has sped up the process. It is still made with the same ingredients and techniques.
First, soybeans are soaked in water then ground to a fine puree with a small amount of water. This mixture is called slurry. The slurry is then boiled and strained to produce soy milk (this is not the same as soy milk` sold commercially). The soy milk then simmered for a short time before a coagulant is added which causes it to separate into curds and whey. Calcium sulfate seems superior to other calcium or magnesium salts. Other coagulants may be lemon juice or vinegar. The curds are then pressed into moulds and the process is complete. Fresh tofu has the appearance of a light cheese and the consistency of a firm custard. It has a very plain,bland flavour which readily absorbs the flavours with which it is prepared.