1, chemical reaction discoloration. Sugarcane juice is rich in nutrition, containing amino acids and sugar from protein. Sugar (sugar containing aldehyde group) in sugarcane juice has Maillard reaction with amino acid or protein, also known as non-enzymatic browning reaction, which produces brown substance (harmless) to discolor sugarcane juice. There are still enzymes in sugarcane that are not inactivated, resulting in discoloration of sugar and oxygen. These are all chemical reactions, which are basically harmless to the body except for the reduction of nutrition in theory.

2. Microorganisms in sugarcane juice use nutrients to produce and reproduce, and produce other colored substances to discolor sugarcane juice. At the same time, the accompanying phenomena are sour taste, foaming, cloudy juice and so on. This sugarcane juice is not drinkable.