Tofu is a common food on the table. According to legend, it was invented by Liu An, the king of Huainan in Han Dynasty. The production process is that the beans are first pulped, and then the most important step is pickling. After embossing, the white and tender tofu is ready.

So why can brine make tofu?

In brine, there are often K+, Na+, Ca2+, Mg2+, Cl-, SO42-, CO32-, HCO3-, B, Li, Br, I, Sr, Rb and Cs plasmas. Bittern contains more than 70% bivalent magnesium. The main chemical component of soybean is protein. Protein is a polymer compound composed of amino acids, and there are free carboxyl and amino groups on the surface of protein. Due to the action of these groups on water, a layer of colloidal substance with water film with the same charge is formed on the surface of protein particles, so that the particles are isolated from each other and will not sink due to collision.

When the bittern is ignited, because bittern is an electrolyte, it will be divided into many charged small particles-positive ions and negative ions. Due to the hydration of these ions, the water film in the protein was seized, so there was not enough water to dissolve protein. In addition, the positive and negative ions of salt inhibited the repulsion caused by the surface charge of protein, which reduced the solubility of protein, and the particles condensed into precipitates. The most intuitive phenomenon is that nothing happens after the bittern is ignited. Protein coagulates to produce gum, and then after filtration and extrusion, tofu is made.

Brine can be used not only to make tofu, but also to treat some diseases in medicine. However, bittern is poisonous, which will lead to poisoning if taken by mistake, and even coma or even death in severe cases.

What if I take it wrong?

1. Feed a lot of cooked soybean milk to make the bittern in the stomach react with soybean milk to produce tofu, thus reducing the toxicity of bittern. Or use milk to absorb heavy metals to detoxify.

2. What about uncooked soybean milk? Fill rice soup first, then warm water, stimulate the posterior pharyngeal wall with your fingers, induce vomiting and gastric lavage, and repeat it several times (vomiting is the most convenient way for our body to deal with eating by mistake).

3. Take egg white, milk, thick rice soup or noodles after gastric lavage to protect gastric mucosa.

Of course, the safest way is to send it to a nearby hospital for professional treatment immediately.