DON't EAT MY TOFU!!

xxxxxxTonight’s dinner is porridge with tofu, simple and delicious dinner all prepared by my roommate Chu Yin Harn. Tofu has always been my favourite dishes, because it is easy to prepare, cheap, low calories and high in nutrition. Especially it was taken out from the fridge and put in your mouth directly; it will melt over your mouth. But of course, tofu can be served hot too. Everyone, including vegetarians can enjoy tofu daily! P/S: Golden citizen, babies and those who encountering tooth pain and wisdom tooth, tofu is the problem solver!! ^^


What is tofu?

xxxxxxTofu, aka soya curd, is a soft cheese-like food of Chinese origin made by curdling soya milk with a coagulant.

How tofu is made?

Soy Bean

xxxxxxThe coagulating tofu from soy milk is similar to the coagulating cheese from milk. Tofu is made by coagulation of soy milk. Pre-made soy milk can be used, however starting from handmade soy milk to ensure better quality, which is produced by soaking, grinding, boiling and straining. Coagulation is the most important step in producing tofu due to the interrelationship of many factors for example soybean variety, soymilk concentration, temperature, pH, and type of coagulant.

xxxxxxCoagulation of the protein and emulsion suspended in the boiled soy milk is the most crucial procedure in the production of tofu. Coagulation needed coagulants. Usually, two types of coagulants (salts and acids) are used. The third type of coagulant is enzyme which is not yet used commercially.

DEEP FRIED TOFU

Taofu Fa!!

Why salt coagulant is chosen?

xxxxxxxNatural calcium sulfate (gypsum) and magnesium chloride (nigari) are the most common tofu salt coagulants used. They have been used for hundreds years in China.

xxxxxxxNigari (chloride type) salts which consist of Magnesium chloride and calcium chloride, both salts having high rate of solubility, whereas gypsum is very slightly soluble in water. Therefore acts differently in soy protein precipitation, the basis for tofu formation. nigari consists primarily of magnesium chloride extract from seawater after the sodium chloride is removed and the water evaporated, which is called Lushui in China.

xxxxxxxHowever, nigari coagulants has weaknesses compare to calcium sulphate and GDL
· As they react with soymilk very rapidly, the coagulated bean curd is destroy while agitation is still going on.
· Nigari coagulate bean curd doesn’t incorporate so much water as the sulfate type, therefore producing lower yield and rougher texture.
· Nigari alone is not suitable to for making silken tofu from hot soymilk because high temperature of soymilk makes it difficult solidify with nigari in short reaction time. However smooth can be made with nigari soymilk is cooled to a low temperature for instance 4 degree celcius.

Magensium chloride

Calcium chloride

xxxxxxxBesides, gymsum (sulfate type) produces tender but slightly tofu. It has low water solubility which is an important factor in determining the velocity of coagulating reaction. Low water solubility reacts slowly with soymilk, hence allow the formation of bean curd with high water holding capacity resulting in soft and smooth tofu comparing to nigari. Gymsum is very easy to be handled even for unskill maker, because the difference of tofu yield is not very large eventhough coagulation is carried out slowly. It also makes a tofu that is rich in calcium, an important mineral for treating and preventing osteoporosis. Many tofu manufacturers choose gymsum to be able to promote their tofu as a good source of calcium.

Gymsum

Why acid coagulant is chosen?

xxxxxxxGlucono delta-lactone (GDL) is manufactured from corn starch by fermentation. GDL is dissolved in cooled soymilk and form gluconic acid gradually, then heat coagulates soymilk with GDL solidified curd with rich water holding properties. GDL gives tofu slightly acidic flavor and texture. The yield of tofu is lower and the texture is crumbly compare to nigari and gymsum.

GDL

xxxxxxxAfter doing the research, I went back to the fridge, and I really see GDL and calcium sulphate stated on the ingredient. Bear in mind to store tofu in the refrigerator.

When Can Babies Have Tofu?

xxxxxxxTofu is a protein food that may be difficult for an immature tummy to digest. Along with meaet and egg yolks and other more complex proteins, most pediatricians recommend offering tofu to the baby who is 8 months of age or older. As Tofu is a soy product, you should not offer it to an infant who has any allergy to soy.