Is there any mung bean in it for cooking? Mung bean skin contains polyphenols, which are easily oxidized into quinones when exposed to oxygen, and continue to polymerize into darker substances, similar to the reason that the deeper the color of tea leaves after soaking. There is no loss of nutrients in the red mung bean soup, but the effect of clearing away heat and toxic materials is greatly reduced. You can soak for a while before cooking, so it will be better to cook for a shorter time.