Green bean soup is a popular summer drink, it tastes good, high nutritional value, many people will cook their own green bean soup at home. Some people cook green bean soup will turn red, this is generally caused by oxidation, this is very difficult to turn back to green, even if the pouring vinegar can not make green bean soup back to green.

Mung bean soup boiled into red how to turn green

After turning red, can not turn green.

When cooking mung bean soup, the polyphenols contained in the skin of mung beans are dissolved, oxidized, polymerized, and turned reddish brown. Generally, this is because the pH of the water is alkaline, or when it encounters oxygen, metal ions and other substances, this phenol will undergo oxidation and polymerization reactions, which leads to the reddening of mung bean soup. Therefore, mung beans that have undergone oxidative polymerization reactions do not turn green.

Green bean soup cooked into red pour some vinegar can become green

Can not.

Mung beans are rich in phenolic substances. When you cook green bean soup, it is really green. When the green bean soup is cooked for a period of time, it will come into contact with the oxygen in the air and begin to oxidize and slowly turn red. Therefore, green bean soup is red, which is a normal reaction. When eating green bean soup, if the green bean soup is not green but red, don't be surprised, normal consumption is enough.

1, with pure water or add a little vinegar to cook

When cooking green bean soup, it is best to use pure water with fewer metal ions, or add vinegar or lemon juice in tap water to adjust the pH of the water, so that the green bean soup remains green.

2, cooking in a pressure cooker or rice cooker

The pressure cooker and rice cooker have better sealing performance, which can reduce the contact between polyphenols and oxygen, reduce the occurrence of oxidation reaction, and prevent the green bean soup from turning red.

3, the cooking time is not too long, only 8-10 minutes

Green beans are relatively easy to cook. If you only have soup, cook them in boiling water for less than 10 minutes.

If you want soup and beans, you can cook them for 7 or 8 minutes and drink them. Then add water and continue to boil the beans until they bloom. There is nothing wrong with having soup and beans.

4, cover the lid to cook

When you cook green bean soup, you can cover the lid of the pot to reduce the contact area of the green bean soup with oxygen, so as to maintain the green color of the green bean soup.