It is not made of real sour plum, but is made of sour plum crystal, citric acid, sugar and essence. People who are angry should eat more sour plums. It can not only calm the liver fire, but also help the spleen and stomach digest and nourish the liver. Sour plum is also a natural throat lozenge, which can gently moisten the inflamed parts of the throat and relieve the pain.