Drinking kumquat boiled in water has the effect of slowing down the hardening of blood vessels, digesting food and reducing phlegm. Kumquat fruit is rich in vitamin A, which has the effect of strengthening the spleen, appetizing and promoting digestion. Drinking tangerine peel boiled in water can clear away heat and detoxify. Orange peel is rich in vitamin C, which is helpful for the body to supplement vitamin C and increase resistance.