Tofu
From Wikipedia, the free encyclopedia
Tofu (豆腐), also
tōfu (the Japanese spelling),
doufu (the Chinese
Pinyin spelling),
dubu (from the Korean spelling),
toufu, or
bean curd (the literal translation), is a
food of
Chinese origin,
[1] made by
coagulating soy milk, and then pressing the resulting curds into blocks. There are many different varieties of tofu, including fresh tofu and tofu that has been processed in some way. Tofu has very little flavor or smell on its own, so it can be used either in savory or sweet dishes, and is often seasoned or marinated to suit the dish.
Tofu originated in ancient
China,
[1] but little else is known about the origins of tofu and its method of production. Tofu and its production technique were subsequently introduced into
Korea, then
Japan during the
Nara period, and
Taiwan. It also spread into other parts of
East Asia as well. This spread likely coincided with the spread of
Buddhism as it is an important source of proteins in
the religion's vegetarian diet.
[2]
Tofu is low in
calories, contains a relatively large amount of
iron and contains little fat. Depending on the coagulant used in manufacturing, the tofu may also be high in
calcium and/or
magnesium. Tofu also contains soy
isoflavones, which can mimic natural human
estrogens and may have a variety of harmful or beneficial effects when eaten in sufficient quantities.
[citation needed]
Production
Tofu is made by coagulating soy milk and pressing the resulting curds. Although pre-made soy milk may be used, most tofu producers begin by making their own soy milk, which is produced by soaking, grinding, boiling and straining dried (or, less commonly, fresh)
soybeans.
Coagulation of the protein and oil (
emulsion) suspended in the boiled soy milk is the most important step in the production of tofu. This process is accomplished with the aid of coagulants. Two types of coagulants (salts and acids) are used commercially.
[3] The third type of coagulant, enzymes, is not yet used commercially but shows potential for producing both firm and "silken" tofu.
Salt coagulants
- Calcium sulfate (gypsum): The traditional and most widely used coagulant to produce Chinese-style tofu. It produces a tofu that is tender but slightly brittle in texture. The coagulant itself has no perceivable taste. Use of this coagulant also makes a tofu that is rich in calcium, an important mineral for treating and preventing osteoporosis. As such, many tofu manufacturers choose to use this coagulant to be able to market their tofu as a good source of calcium.
- Chloride-type Nigari salts or Lushui ( Traditional: 鹵水, 滷水; Simplified:卤水 in Chinese) - Magnesium chloride and calcium chloride: Both of these salts have a high solubility rate in water and affect soy protein in the same way, whereas gypsum is only very slightly soluble in water and acts differently in soy protein precipitation, the basis for tofu formation. These are the coagulants used to make tofu with a smooth and tender texture. In Japan, a white powder called nigari, which consists primarily of magnesium chloride, is produced from seawater after the sodium chloride is removed and the water evaporated, which is called Lushui (卤水) in China. Depending on its production method, nigari/Lushui may also contain small quantities of magnesium sulfate (Epsom salt), potassium chloride, calcium chloride, and trace amounts of other naturally occurring salts. Although the term nigari is derived from nigai, the Japanese word for "bitter," neither nigari nor pure magnesium chloride imparts a perceivable taste to the finished tofu. Calcium chloride is a common coagulant for tofu in North America.[4]. Fresh clean sea water itself can also be used as a coagulant.[5]
Acid coagulants
- Glucono delta-lactone (GDL): A naturally occurring organic acid also used in cheese making, which produces a very fine textured tofu that is almost jelly-like. This coagulant is used especially for "silken" and softer tofus, and confers an almost imperceptible sour taste to the finished product.[6] Commonly used together with calcium sulfate to give soft tofu a smooth tender texture.
Enzyme coagulants
- Among enzymes that have been shown to produce tofu are papain, and alkaline and neutral proteinases from microorganisms. In the case of papain, the enzyme to substrate ratio, by weight, was held constant at 1:400. An aliquot of 1% crude papain was added to "uncooked" soy milk at room temperature and heated to 90–100 degrees Celsius.[4]
Contemporary tofu manufacturers may choose to use one or more of these coagulants, since they each play a role in producing a desired texture in the finished tofu.
[6] Different textures result from different pore sizes and other microscopic features in tofus produced using each coagulant. The coagulant mixture is dissolved into water, and the solution is then stirred into boiled soy milk until the mixture curdles into a soft
gel.
[3]
The curds are processed differently depending on the form of tofu that is being manufactured. For soft silken tofu (
嫩豆腐;
nèn dòufu) or tofu flower (
豆花,
dòuhuā) the soy milk is curdled directly in the tofu's selling package. For standard firm Asian tofu, the soy curd is cut and strained of excess liquid using
cheese cloth or
muslin and then lightly pressed to produce a soft cake. Firmer tofus, such as Asian dry tofu (
荳乾) or Western types of tofu, are further pressed to remove even more liquid. In Vietnam, the curd is strained and molded in a square mold and the end product is called
đậu khuôn (molded bean) or
đậu phụ (one of the Vietnamese ways to pronounce the Chinese doufu). The tofu curds are allowed to cool and become firm. The finished tofu can then be cut into pieces, flavored or further processed.
Although tartness is sometimes desired in dessert tofu, the acid used in flavoring is usually not the primary coagulant since it is not desirable to the flavor or texture of the resulting tofu to add it in a sufficiently high concentration so as to induce coagulation. A sour taste in tofu and a slight cloudiness in its storing liquid is also usually an indication of bacterial growth and, hence, spoilage.
Varieties
There is a wide variety of tofu available in both Western and Eastern markets. Despite the daunting variety, tofu products can be split into two main categories:
fresh tofu, which is produced directly from
soy milk, and
processed tofu, which is produced from fresh tofu. Tofu production also creates important side products which are often used in various cuisines.
Fresh tofu
Depending on the amount of water that is extracted from the tofu curds, fresh tofu can be divided into three main varieties.
Silken tofu with soy sauce and a decorative carrot slice
Soft/silken tofu
Soft/silken tofu(
嫩豆腐 or
滑豆腐,
nèn dòufu or
huá dòufu, in
Chinese, lit. "soft tofu" or "smooth tofu";
絹漉し豆腐,
kinugoshi tōfu in
Japanese, lit. "silk-filtered tofu";
순두부,
純豆腐,
sundubu in
Korean, lit. "pure tofu") undrained tofu contains the highest moisture content of all fresh tofus.
[7] Its texture can be described as similar to that of very fine
custard. In Japan and Korea, traditional soft tofu is made with
seawater.
[8][9][10][11][12]
Douhua (
豆花,
dòu huā or
豆腐花,
dòufu huā in Chinese), or
tofu brain (
豆腐腦 or
豆腐脑,
dòufu naǒ in Chinese), often eaten as a dessert, but sometimes with salty pickles or hot sauce added instead, is another type of soft tofu with an even higher moisture content. Because it is nearly impossible to pick up this type of tofu with
chopsticks, it is generally eaten with a spoon. With the addition of flavorings such as finely chopped
spring onions, dried
shrimp,
soy sauce and
chilli sauce,
douhua is a popular breakfast dish across China.
Some variations exists for soft tofus. Black douhua (
黑豆花) is a type of silken tofu made from plain black soy beans and soybeans, which is usually made into
dòuhuā (
豆花) rather than firm or dry tofu. The texture of black bean tofu is slightly more gelatinous than regular douhua and the color is greyish in tone. This type of tofu is eaten for the earthy "black bean taste."
Edamame tofu is a Japanese variety of
kinugoshi tōfu made from
edamame (fresh green soybeans); it is pale green in color and often studded with whole
edamame.
Firm tofu
Firm tofu (called
老豆腐 lǎo dòufu in Chinese;
木綿豆腐,
momendōfu in
Japanese, lit. "cotton tofu"): Although drained and pressed, this form of fresh tofu still contains a great amount of moisture. It has the firmness of raw meat but bounces back readily when pressed. The texture of the inside of the tofu is similar to that of a firm custard. The skin of this form of tofu has the pattern of the muslin used to drain it and is slightly more resilient to damage than its inside. It can be picked up easily with
chopsticks.
[7][13]
Dried tofu
Dried tofu (
豆乾,
dòu gān in Chinese, lit. "dry tofu"): An extra firm variety of tofu with the least amount of moisture of all fresh tofu. It has the firmness of fully cooked meat and a somewhat rubbery feel similar to
paneer. When sliced thinly, this tofu can be crumbled easily. The skin of this form of tofu has the pattern of the muslin used to drain and press it. Western firm tofu is milled and reformed after the pressing and sometimes lacks the skin with its cloth patterning. One variety of dried tofu is pressed especially flat and sliced into long strings with a cross section smaller than 2 mm × 2 mm. Shredded dried tofu (
豆乾絲,
dòu gān sī in Chinese, or simply
乾絲,
gān sī), which looks like loose cooked
noodles, and can be served cold, stir-fried, or similar in style to Japanese
aburaage.
[13][14] Fresh tofu is usually sold completely immersed in water to maintain its moisture content.
[2]
Processed tofu
Many forms of processed tofus exist, due to the varied ways in which fresh tofu can be used. Some of these techniques likely originate from the need to preserve tofu before the days of refrigeration, or to increase its shelf life and longevity. Other production techniques are employed to create tofus with unique textures and flavors.
[15]
Fermented
- Pickled tofu (豆腐乳 in Chinese, pinyin: dòufu rǔ, lit. "tofu dairy," or 腐乳; chao in Vietnamese): Also called "preserved tofu" or "fermented tofu," this food consists of cubes of dried tofu that have been allowed to fully air-dry under hay and slowly ferment from aerial bacteria.[15] The dry fermented tofu is then soaked in salt water, Chinese wine, vinegar, and minced chiles, or a unique mixture of whole rice, bean paste, and soybeans. In the case of red pickled tofu (紅豆腐乳 in Chinese, Pinyin: hóng dòufu rǔ), red yeast rice (cultivated with Monascus purpureus) is added for color.[16]
- Stinky tofu (臭豆腐 in Chinese, Pinyin: chòu dòufu): A soft tofu that has been fermented in a unique vegetable and fish brine.[15] The blocks of tofu smell strongly of certain pungent cheeses, and are described by many as rotten and fecal. Despite its strong odor, the flavor and texture of stinky tofu is appreciated by aficionados, who describe it as delightful. The texture of this tofu is similar to the soft Asian tofu that it is made from. The rind that stinky tofu develops from frying is said to be especially crisp, and is usually served with soy sauce, sweet sauce, and/or hot sauce.
Flavored
Chili-peppered egg tofu from Ipoh, Malaysia.
Flavors can be mixed directly into curdling soy milk while the tofu is being produced.
- Sweet: Common sweet dessert tofus include peanut tofu (落花生豆腐, luòhuāshēng dòufu in Chinese and jimami-dōfu in Japanese), almond tofu (杏仁豆腐, xìngrén dòufu in Chinese; 杏仁豆腐, annindōfu in Japanese), mango tofu, and coconut tofu. In order to produce these forms of tofu, sugar, fruit acids, and flavorants are mixed into soy milk prior to curdling. Most sweet tofus have the texture of silken tofu and are served cold.
- Products called "almond tofu" in some cases are actually not made from tofu but are instead gelatinous desserts made from agar or gelatin and whitened with milk or coconut milk. In Japan these are canned with syrup and sold as a sweet dessert.
- Savory: Egg tofu (Japanese: 玉子豆腐, 卵豆腐, tamagodōfu) (Chinese: 蛋豆腐, dàn dòufu; often called 日本豆腐, rìbĕn dòufu, lit. "Japan bean curd") is the main type of savory flavored tofu. Whole beaten eggs are filtered and incorporated into the soy milk before the coagulant is added. The mixture is filled into tube shaped plastic bags and allowed to curdle. The tofu is then cooked in its packaging and sold. Egg tofu has a pale golden color that can be attributed to the addition of egg and, occasionally, food coloring. This tofu has a fuller texture and flavor than silken tofu, which can be attributed to the presence of egg fat and protein.
Fried
- With the exception of the softest tofus, all forms of tofu can be fried. Thin and soft varieties of tofu are deep fried in oil until they are light and airy in their core (豆泡 or 豆卜 in Chinese, dòupào, literally "bean bubble," describing the shape of the fried tofu as a bubble).
- Tofus such as firm Asian and dry tofu, with their lower moisture content, are cut into bite-sized cubes or triangles and deep fried until they develop a golden-brown, crispy surface (炸豆腐 in Chinese, zhà dòufu, lit. "fried tofu"). These may be eaten on their own or with a light sauce, or further cooked in liquids; they are also added to hot pot dishes or included as part of the vegetarian dish called luohan zhai.
- Aburaage (油揚げ): Japanese fried tofu for Inari-sushi.
Frozen
Thawed and sliced frozen tofu
- Thousand layer tofu (千葉豆腐, 凍豆腐 or 冰豆腐 in Chinese, literally "thousand layer tofu" or "frozen tofu"): By freezing tofu, the large ice crystals that develop within the tofu result in the formation of large cavities that appear to be layered (pseudostratified). The frozen tofu takes on a yellowish hue in the freezing process. Thousand layer tofu is commonly made at home from Asian soft tofu though it is also commercially sold as a specialty in parts of Taiwan. This tofu is defrosted and sometimes squeezed of moisture prior to use.[2]
- Koyadofu (kōyadōfu, 高野豆腐 in Japanese): The name comes from Mount Koya, a center of Japanese Buddhism famed for its shōjin ryōri, or traditional Buddhist vegetarian cuisine. It is sold in freeze-dried blocks or cubes in Japanese markets. It must be soaked in water before eating, and is typically simmered in dashi, sake or mirin and soy sauce. In shōjin ryōri, vegetarian kombu dashi, made from seaweed, is used. When prepared in the usual manner, it has a spongy texture and mild sweet and savory flavor. A similar form of freeze-dried tofu, in smaller pieces, is found in instant soups (such as miso soup), in which the toppings are freeze-dried and stored in sealed pouches.
Tofu is also a main dish, especially this type which is commonly used and is in high demand in eastern Asia.
Byproducts of tofu production
Tofu production creates some edible byproducts. Food products are made from the protein-oil film, or "skin," which forms over the surface of boiling soy milk in an open shallow pan. The leftover solids from pressing soy milk is called
okara.
Tofu skin
Tofu skin is produced through the boiling of soy milk, in an open shallow pan, thus producing a film or skin composed primarily of a soy protein-lipid complex on the liquid surface.
[2] The films are collected and dried into yellowish sheets known as
soy milk skin (
腐皮,
fǔ pí in Chinese;
湯葉,
yuba in Japanese). Its approximate composition is : 50–55% protein, 24–26% lipids (fat), 12% carbohydrate, 3% ash, and 9% moisture.
[17]
The skin can also be bunched up to stick form and dried into something known as "tofu bamboo" (
腐竹,
fǔ zhú in Chinese;
phù trúc in Vietnamese;
kusatake, Japanese), or myriad other forms. Since tofu skin has a soft yet rubbery texture, it is folded or shaped into different forms and cooked further to imitate meat in vegetarian cuisine.
Some factories dedicate production to tofu skin and other soy membrane products.
Okara
Okara (おから?) (
雪花菜,
xuě huā caì, lit. "snowflake vegetable";
豆腐渣,
dòufu zhā, lit. "tofu sediment/residue";
kongbiji, 콩비지 in Korean), sometimes known in the west as soy pulp, is the fibre, protein, and starch left over when soy milk has been extracted from ground soaked soybeans.
[2] Although it is mainly used as animal feed in most tofu producing cultures, it is sometimes used in Japanese and Korean cuisines. It is also an ingredient for
vegetarian burgers produced in many western nations.
Non-tofu "tofus"
Due to their Asian origins and their textures, many food items are called "tofu" even though their production processes are not technically similar. For instance, many sweet almond tofus are actually gelatinous desserts made from
agar or
gelatin and whitened with
milk or
coconut milk more similar to Japanese
anmitsu. As well, some foods such as Burmese tofu are not coagulated from the "milk" of the legume but rather set in a manner similar to soft
polenta,
Korean muk, or the
jidou liangfen of
Yunnan province of
Southwest China.
Burmese tofu
To hpu (Burmese tofu), in two forms: fresh and
fritters Burmese tofu (
to hpu in
Burmese) is a type of legume product made from
besan (
chana dal) flour the
Shan variety uses
yellow split pea flour instead. Both types are yellow in color and generally found only in
Myanmar, though the
Burman variety is also available in some overseas restaurants serving
Burmese cuisine.
[18]
Burmese tofu may be fried as fritters cut in rectangular or triangular shapes. Rice tofu, called
hsan to hpu (or
hsan ta hpo in Shan regions) is made from rice flour (called
hsan hmont or
mont hmont) and is white in color, with the same consistency as yellow Burmese tofu when set. It is eaten as a salad in the same manner as yellow tofu.
Preparation
Tofu has very little flavor or smell on its own. Consequently tofu can be prepared either in savory or sweet dishes, acting as a bland background for presenting the flavors of the other ingredients used. As a method of flavoring it is often marinated in soy sauce, chilis, sesame oil, etc.
Eastern methods
In Asian cooking, tofu is eaten in myriad ways, including raw, stewed, stir-fried, in soup, cooked in sauce, or stuffed with fillings.
Lightly flavored
The light greenish "bean" smell of tofu is much enjoyed in East Asian cuisines and fresh tofu is often eaten plain or simply flavored.
In
Japan, a common lunch in the summer months is
hiyayakko (
冷奴), silken or firm Asian tofu served with freshly grated
ginger,
scallions, and
soy sauce. In many parts of
China, fresh tofu is similarly eaten with soy sauce or further flavored with
katsuobushi shavings,
century eggs (
皮蛋), and
sesame seed oil.
Dòuhuā (
豆花), is a soft tofu dish. The fresh tofu is served warm and here dressed with sweet syrup.
Lamma Island,
Hong Kong.
In
Chinese cuisine,
Dòuhuā (
豆花) is served with toppings like boiled
peanuts,
azuki beans, cooked
oatmeal,
tapioca,
mung beans and a syrup flavored with
ginger or
almond. During the summer,
dòuhuā is served with crushed ice; in the winter, it is served warm.
[19]
In
Korean cuisine,
dubu jorim consists of cubes of firm tofu that are pan fried and seasoned with soy sauce, garlic, and other ingredients. Cubes of cold, uncooked tofu seasoned with soy sauce, scallions, and ginger, prepared in a manner similar to the Japanese
hiyayakko are also enjoyed.
In the
Philippines, the sweet delicacy
taho is made of fresh tofu with brown sugar syrup and
sago. The Malaysian version of taho or douhua is called tofufa. Warm soft tofu is served in 'slices' (due to being scooped using a flat spoon from a wooden bucket) in a bowl with either pandan-flavored sugar syrup or palm sugar syrup.
In Vietnam,
dòuhuā is pronounced
đậu hủ. This variety of soft tofu is made and carried around in an earthenware jar. It is served by being scooped into a bowl with a very shallow and flat spoon, and eaten with either powdered sugar and lime juice or with a ginger-flavored syrup. It is generally eaten hot, even during summer.
Fried
A common cooking technique in many parts of East and Southeast Asia involves deep frying tofu in
vegetable oil,
sunflower oil, and
canola oil to varied results. Although tofu is often sold preprocessed into fried items, pre-fried tofu is seldom eaten directly and requires additional cooking. Depending on the type of tofu used, the texture of deep fried tofu may range from crispy on the outside and custardy on the inside, to puffed up like a plain
doughnut. The former is usually eaten plain in Chinese cuisine with garlic soy sauce, while the latter is either stuffed with
fish paste or cooked in soups.
[19] In Japan, cubes of lightly coated and fried tofu topped with a
kombu dashi-based sauce are called
agedashi-dofu (
揚げ出し豆腐). Soft tofu that has been thinly sliced and deep fried, known as
aburage in Japan, is commonly
blanched, seasoned with
soy sauce and
mirin and served in dishes such as
kitsune udon.
Aburage is sometimes also cut open to form a pocket and stuffed with
sushi rice; this dish is called
inarizushi (
稲荷寿司) .
Soups, stews, and braised dishes
Yudofu, or tofu in hot water.
A rather famous hot
Sichuan preparation using firm Asian tofu is
mápó dòufu (
麻婆豆腐). This involves braised tofu in a
beef, chili, and a fermented bean paste sauce. In the
Shanghai region it is called
málà dòufu (
麻辣豆腐).
Dried tofu is usually not eaten raw but first stewed in a mixture of soy sauce and spices. Some types of dried tofu are preseasoned with special blends of spices, so that the tofu may either be called "five spice tofu" (
五香豆腐) or "soy sauce stewed tofu" (
鹵水豆腐). Dried tofu is typically served thinly sliced with chopped
green onions or with slices of meat for added flavor. Most dried tofu is sold after it has been fried or pre-stewed by tofu vendors.
[19]
Soft tofu can also be broken up or mashed and mixed with raw ingredients prior to being cooked. For example, Japanese
ganmodoki is a mixture of chopped vegetables and mashed tofu. The mixture is bound together with starch and deep fried. Chinese families sometimes make a steamed
meatloaf or
meatball dish from equal parts of coarsely mashed tofu and ground pork. In India, tofu is also used as a low fat replacement for
paneer providing the same texture with similar taste.
Tofu bamboos are often used in
lamb stew or in a
dessert soup. Tofu skins are often used as wrappers in
dim sum. Freeze-dried tofu and frozen tofu are rehydrated and enjoyed in savory soups. These products are often taken along on camping trips since a small bag of these dried tofu can provide protein for many days.
In Korean cuisine, soft tofu (
sundubu in Korean) is used to make a thick soup called
sundubu jjigae (
순두부 찌개).
As flavoring
Pickled tofu is commonly used in small amounts together with its soaking liquid to flavor stir-fried or braised
vegetable dishes (particularly
leafy green vegetables like
water spinach). It is often eaten directly as a
condiment with rice or
congee.
Western methods
Generally, the firmer styles of tofu are used for
kebabs, mock meats, and dishes requiring a consistency that holds together, while the softer styles can be used for desserts, soups, shakes, and sauces.
Firm western tofus can be barbecued since they will hold together on a barbecue grill. These types of tofu are usually marinated overnight as the marinade does not easily penetrate the entire block of tofu (techniques to increase penetration of marinades are stabbing repeatedly with a fork or freezing and thawing prior to marinating). Grated firm western tofu is sometimes used in conjunction with
TVP as a meat substitute. Softer tofus are sometimes used as a dairy-free or low-calorie filler. Silken tofu may be used to replace cheese in certain dishes (such as
lasagna).
Tofu has also been fused into other cuisines in the west, for instance used in Indian-style curries.
Tofu and soy protein can be industrially processed to match the textures and flavors to the likes of
cheese,
pudding,
eggs,
bacon etc. Tofu's texture can also be altered by
freezing,
pureeing, and
cooking. In
the Americas,
Europe,
Australia and
New Zealand, tofu is frequently associated with
vegetarianism and
veganism as it is a source of high-quality, non-animal protein.
History
Tofu and potatoes grilled at a street stall in
Yuanyang, Yunnan province, China
Tofu originated in ancient
China,
[1] although little else is known about the exact historic origins of tofu and its method of production. While there are many theories regarding tofu's origins, historical information is scarce enough as to relegate the status of most theories to either speculation or legend. Like the origins of
cheese and
butter, the exact origin of tofu production may never be known or proven.
What is known is that tofu production is an ancient technique. Tofu was widely consumed in ancient
China, and techniques for its production and preparation were eventually spread to many other parts of
Asia.
Three theories of origin
The most commonly held of the three theories of tofu's origin maintains that tofu was invented in northern China around 164 BC by Lord
Liu An, a
Han Dynasty prince. Although this is possible, the paucity of concrete information about this period makes it difficult to conclusively determine whether Liu An invented the method for making tofu. Furthermore, in
Chinese history, important inventions were often attributed to important leaders and figures of the time.
[2][13]
Another theory states that the production method for tofu was discovered accidentally when a slurry of boiled, ground soybeans was mixed with impure sea salt. Such sea salt would likely have contained calcium and magnesium salts, allowing the soy mixture to curdle and produce a tofu-like gel.
[20] This may have possibly been the way that tofu was discovered, since soy milk has been eaten as a savory soup in ancient as well as modern times. Its technical plausibility notwithstanding, there is little evidence to prove or disprove that tofu production originated in this way.
[13]
The last group of theories maintains that the ancient Chinese learned the method for the curdling of soy milk by emulating the milk curdling techniques of the
Mongolians or
East Indians. For, despite their advancement, no technology or knowledge of culturing and processing milk products existed within ancient Chinese society. The primary evidence for this theory lies with the etymological similarity between the Chinese term for Mongolian fermented milk (
rufu, which literally means "milk spoiled") and the term
doufu or tofu. Although intriguing and possible, there is no evidence to substantiate this theory beyond the point of academic speculation.
[13]
In Asia
Although its development likely preceded Liu An, tofu is known to have been a commonly produced and consumed food item in
China by the 2nd century BC. Although the varieties of tofu produced in ancient times may not have been identical to those of today, descriptions from writings and poetry of the
Song and
Yuan Dynasty show that the production technique for tofu had already been standardized by then, to the extent that they would be similar to tofu of contemporary times.
In China, tofu is traditionally used as a food offering when visiting the graves of deceased relatives. It is claimed that the spirits (or ghosts) have long lost their chins and jaws, and that only tofu is soft enough for them to eat. Before
refrigeration was available in China, tofu was often only sold during the winter time, due to the tofu not spoiling in the colder weather. During the warmer months, any leftover tofu would be spoiled if left for more than a day. Chinese war hero
Guan Yu used to be a tofu maker before he enlisted in the army. Chinese martial arts expert and hero,
Yim Wing-chun, was a celebrated tofu maker in her village. (Tofu as such plays a part in the 1994 movie about her life,
"Wing Chun".)
Tofu and its production technique were subsequently introduced into
Japan in the
Nara period (late eighth century) as well as other parts of
East Asia. The earliest document of tofu in Japan shows that the dish was served as an offering at the
Kasuga Shrine in
Nara in 1183
[21]. The book
Tofu Hyakuchin (
豆腐百珍), published in the
Edo period, lists 100 recipes for cooking tofu.
The rise in acceptance of tofu likely coincided with that of
Buddhism as it is an important source of proteins in the religion's vegetarian diet.
[2] Since then, tofu has become a
staple in many countries, including
Vietnam,
Thailand, and
Korea, with subtle regional variations in production methods, texture, flavor, and usage.
Tofu is so highly esteemed in Korean culture that the menus of many Korean restaurants are based almost entirely on tofu, including some which feature only
sundubu jjigae (a stew made with soft tofu) and
gochujang (red chili paste).
[citation needed]
Tofu in the
Philippines is essential to the daily diet, as
taho, widely eaten as breakfast, or
tokwa (a dry fried variation), which is a staple or alternative to meat in main meals, and in numerous regional dishes. Tofu was introduced to the archipelago in the 10-13th centuries by
Song Chinese mariners and merchants, along with many different foods which had become staples of the Filipino diet. The use and production of Tofu were first limited to urban centers with influential Chinese minorities, such as
Tondo or
Cebu, but we're quickly spread to even remote native villages and islands, long before the Spanish arrival in the 17th century.
In Malaysia, Singapore, Thailand and Indonesia, tofu or tahu is widely available and used in many Malay dishes such as sayur goreng, masak lodeh, tahu sumbat, rojak, pecal, gado-gado, lontong and some curries. The Malaysian and Singaporean Indians use tofu in their cuisine such as Indian mee goreng and rojak pasembor. The makers of tofu in these countries were originally the Chinese but tofu now is made by non-Chinese as well.
In the West
Pre-flavored tofu from
Albert Heijn supermarket chain, the Netherlands
Tofu was not well known to most Westerners before the middle of the 20th century. With increased cultural contact between the West and Asia and growing interest in
vegetarianism, knowledge of tofu has become widespread. Numerous types of pre-flavored tofu can be found in many supermarket chains throughout the West.
Nutrition and health information
Protein
Tofu is relatively high in
protein, about 10.7% for firm tofu and 5.3% for soft "silken" tofu with about 2% and 1% fat respectively as a percentage of weight.
[22]
In 1995, a report from the
University of Kentucky, financed by
The Solae Company St. Louis, Missouri (the PTI division of DuPont), concluded that soy protein is correlated with significant decreases in serum cholesterol, Low Density Lipoprotein
LDL (bad cholesterol) and triglyceride concentrations.
[23] However, High Density Lipoprotein
HDL (good cholesterol) did not increase. Soy
phytoestrogens (
isoflavones: genistein and daidzein) absorbed onto the soy protein were suggested as the agent reducing serum cholesterol levels. On the basis of this research, PTI, in 1998, filed a petition with
Food and Drug Administration for a health claim that soy protein may reduce cholesterol and the risk of heart disease.
The FDA granted this health claim for soy: "25 grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease."
[24] For instance, 100 grams of firm tofu contains 15.78 grams of soy protein.
[25] In January 2006, an
American Heart Association review (in the journal
Circulation) of a decade-long study of soy protein benefits showed only a minimal decrease in cholesterol levels, but it compared favorably against animal protein sources.
[26]
Isoflavones
Soy isoflavones have not been shown to reduce post
menopause hot flashes in women or to help prevent cancers of the breast, uterus or prostate. Thus, soy isoflavone supplements in food or pills is not recommended.
[27]
A study done by the Pacific Health Research Institute followed over 3000 Japanese men between 1965 and 1999, which showed a positive correlation between
cerebral atrophy and consumption of tofu.
[28] However, this study by L.R. White, et al., from the National Institute of Aging,
NIH, was rejected as not credible by the
Food and Drug Administration.
[24]
Sales and distribution
In many countries in the West, tofu can be obtained in
Asian markets, farmers' markets, and
health food stores. In the
Netherlands it is also sold in many supermarkets. Depending on its local popularity, many grocery stores also stock tofu. The largest provider of tofu products in the
United States is House Foods America Corp, a subsidiary of Japan based company,
House Foods Corp (
ハウス食品）.
House Foods America Corp. has tofu plants in California and New Jersey with a combined capacity of manufacturing 350,000 pieces of tofu per day. Other major brands are
Vitasoy, a subsidiary of a Hong Kong based company, which also manufactures the brands Nasoya and Azumaya; and Mori-Nu (Morinaga Nutritional Foods), a subsidiary of
Morinaga Milk Industry (森永乳業) of Japan, which pioneered the sale of shelf-stable,
aseptically packaged tofu.
Fresh local tofu varieties are often available in Western areas with high concentrations of Asian populations.
In the East, tofu may be produced locally by relatively small vendors or distributed widely by large national brands. Fresh tofu is usually bought from local vendors and is sold directly from large bins or pots at
street markets. Asian firm tofu and "tofu flower" are commonly sold in this manner and are usually no more than a few hours old. Tofu that is sold by large manufacturers often comes packaged in sealed plastic cartons or tubes, and may be at most two weeks old. In Chinese
supermarkets, tofu can be found in many different flavors and grades of consistency.
Most silken and flavored tofus are produced by large factories. This is due to the fact that such factories have the facilities to meet the required sanitary conditions for production of these forms of tofu on a large scale. In Japan, silken tofu is made daily without preservatives and is considered unsellable if it sits unsold in the supermarket for 2 days. Firm tofu is not eaten in Japan without frying as it's considered "crude".
Etymology
The English word "tofu" comes from the
Japanese tōfu (
豆腐),
listen (help·info) which itself derives from the
Chinese dòufu (
豆腐 or
荳腐). Although in both languages the characters together translate as "bean curd," the literal meaning of the individual characters is "bean" (
豆) and "curdled" (
腐).
[29][30
- Apparently, someone still refuses to eat normal tofu and insist on eating EGG TOFU.
- Stephanie said stinky tofu smells like earwax.
- I, just love tofu, not the stinky one though... ^^
