Hello! But the harmful alkaline surface is sodium carbonate, but I don't understand that sodium carbonate is alkali! ! It is a kind of salt, but people are used to calling it alkaline noodles or soda ash. Add it when steaming steamed bread to adjust the acidity. In addition, its biggest use is a raw material of "causticizing caustic soda" invented by China chemist Mr. Hou, that is, sodium carbonate reacts with calcium hydroxide to prepare more expensive sodium hydroxide. The alkaline surface is mainly Na2CO3. Sodium carbonate, commonly known as alkaline noodles. When making steamed bread, the acid produced by fermentation is neutralized with alkaline flour, and a large amount of carbon dioxide gas is covered to make steamed bread fluffy and porous. Too much, very bitter. Without steamed bread, you will feel sour. Alkaline noodles used in other food industries are also so desirable! thank you