Soymilk pudding

When Chinese dessert is mentioned, many will think of soymilk pudding ( called tau fu fa in Chinese). It is a very popular Chinese dessert (I’m sure many people love it, including ME^^). The texture of soymilk pudding is so smooth that when it slides down the throat, it creates a great temptation. Not only the Chinese, but even the Malays have started to love this dessert. I’ve seen many Malay hawkers selling soymilk pudding.

Soymilk pudding(Tau Fu Fa)

For those who are not familiar to soymilk pudding...

Soymilk pudding or sometimes referred to as tofu pudding is made from coagulated soy bean milk, served with sugar syrup. Soymilk pudding is usually served hot or cold.

Delicious Soymilk pudding served with brown sugar

Do you know?

As mentioned earlier, soymilk pudding is made from COAGULATED soy bean milk. Have you thought of this, what makes soy bean milk coagulate?

The answer is GYPSUM POWDER. Gypsum powder is used traditionally to coagulate soy bean milk and till now, gypsum powder plays the same role.

GYPSUM POWDER (one of the main ingredient in making soy milk pudding)

GYPSUM POWDER that coagulates soymilk pudding

What is GYPSUM POWDER?

Have u heard of gypsum powder? What is gypsum actually? Another name for gypsum (which I feel chemistry student will be familiar with) will be calcium sulphate. Gypsum powder is the most common sulphate mineral, characterized by the chemical formula of CaSO₄ · 2H₂O. Gypsum is one of several evaporate minerals and this mineral groups are chlorides, carbonates, borates, nitrates and sulphate. These minerals precipitate in seas, lakes, caves and salt flats. When gypsum is heated or subjected to solutions with large salinities, gypsum will be converted to bassanite(CaSO₄·H₂O) or anhydrite(CaSO₄).

Structure of GYPSUM

GYPSUM crystal

What are the uses of GYPSUM?

Guess what? Gypsum is used chiefly in manufacturing Plaster of Paris. Plaster of Paris is made by heating gypsum in air. A hemihydrates will formed when water of crystallization is driven off. When gypsum loses 75% of its water of crystallization, it forms Plaster of Paris.

Formation of PLASTER OF PARIS

Some example uses of PLASTER OF PARIS:

Statue made from PLASTER OF PARIS

PLASTER OF PARIS used in setting fractured bone

GYPSUM

Other uses of gypsum include .production of wallboard, in agriculture to loosen clay-rich soils, and in the manufacture of fertilizer.

Can you believe that gypsum powder that is used to manufacture Plaster of Paris is used to coagulate soymilk pudding? Many claim that soymilk pudding that uses gypsum powder as a coagulant bring negative effects to consumers. The negative effects include formation of kidney stone and backache.

Since soymilk pudding with gypsum powder has its drawback, soymilk pudding lover will not be able to enjoy the dessert anymore. Of course not! Besides gypsum powder, another coagulant can substitute the role of gypsum powder. The coagulant mentioned is referred to as GDL (glucono delta-lactone).

GDL?

An acidic type of coagulant, GDL (glucono delta-lactone) is a fine, white, odourless crystalline powder. It dissolves easily in water and is sparingly soluble in alcohol. It hydrolyses to gluconic acid in water. GDL is prepared by direct crystallization from the aqueous solution of gluconic acid, which is the active agent as acidulant. Likewise, for the coagulation of soymilk pudding, gluconic acid is the active coagulating agent.

GDL

Chemical Structure of GDL

Huge bag of GDL

Hmm...What are the uses of GDL?

GDL is used widely in coagulating tofu (beancurd) especially in Japan. Coagulation of the soy protein in soy milk is the most important step in manufacturing tofu. The protein in soy milk is mostly soluble at a neutral pH but insoluble in acidic state or in the presence or alkaline elements. The gradual acidification produced by GDL initiates the curdling of the protein in soy milk. GDL coagulates soymilk to form silken tofu. Compared to the other type of coagulatants, GDL gives the best texture on the basis of smoothness.

Tofu(beancurd) that uses GDL as coagulant

Same goes to soymilk pudding, GDL plays the same role like how it coagulates tofu. Like what gypsum powder does, GDL gives the same effect and smoothness to the soymilk pudding. GDL does not bring negative effects like gypsum powder. Therefore, Soymilk lover have no worries in enjoying the excellent dessert anymore.^^