Polyphenols in mung bean soup are unstable, and it is easy to oxidize in the air to produce oxidative polymerization reaction, which makes mung bean soup turn red, so the summer-relieving effect of mung bean soup will be weakened.

Extended data:

Put the washed mung beans into a stainless steel pot or a ceramic pot, add a proper amount of water, and the ratio of mung beans to water is 1: 10, and boil over high fire for ten minutes. About ten minutes later, the mung bean has not completely cracked. At this time, the color of mung bean soup is green and clear, with the highest content of polyphenols and the strongest effect of relieving summer heat.

When using a container, it is best not to choose an iron pan, which is easy to be oxidized. In addition, in order to prevent the oxidation process of polyphenols, a few drops of white vinegar or lemon juice can be added.

References:

People's Daily Online-Does the mung bean soup take a long time to relieve summer heat? Expert: 10 minutes is the best