We eat a variety of foods. Among them, let’s take a look at some of the foods that are hardened, such as cheese, tofu, and konjac. Do you know the mechanism how they harden?
Enzymatic Decomposition of Proteins
It is used to make cheese, such as leipajuusto.
Cohesion Due to pH Change
It is used to make cottage cheese and other cheeses.
Cohesion by Salting Out
This is used in the production of tofu and konjac.
Tofu is solidified by heating soy milk and adding salt called Nigari to it. The protein in soy milk is in a stable state called colloid (hydrophilic colloid). In order to solidify it, the soy milk is first heated to denature the protein and make it easier to precipitate. Then, by adding Nigari, the colloid is made less soluble in water and precipitated.
This method of precipitating hydrophilic colloids by adding a large amount of electrolytes is called salting out.
The mechanism of konjac solidification is also based on colloidal salting out. Glucomannan, the main component of konjac, forms a hydrophilic colloid that dissolves well in water. Konjac is made by adding a strong basic coagulant to it.
Thermal Denaturation of Proteins
It is used to make egg tofu, chawanmushi, cheese, and tofu.
Acid Denaturation of Proteins
This is used to make cottage cheese and ricotta cheese.
This is used to make edamame tofu, jelly and so on.
Gelatin is made up of a network of proteins. When gelatin is placed in water and heated, the proteins in the gelatin loosen and move freely. To our eyes, the gelatin has dissolved in the hot water.
Gluing of Starch
This is used to make sesame tofu, peanuts tofu.
Starch is a substance made up of chains of glucose sugars that are tightly folded together. Normally, there is a strong hydrogen bond between these chains. Therefore, the chains do not come apart.
Categorize Food by Mechanism
We usually categorize dishes by their ingredients or how they are made. This time, I thought a little deeper and classified them by their mechanisms. When a dish does not turn out well, thinking about the mechanism in this way may help you solve the problem.