1. As a quality improver, it can improve the complex metal ions, pH value and ionic strength of food, thus improving the binding force and water retention of food. China stipulates that it can be used in cheese, with the maximum consumption of 5g/kg; The maximum usage of western ham, meat, fish, shrimp and crab is 3.0g/kg. Maximum use in cans, juices, beverages and dairy products is 0.5g/kg.

　　2. Used as analytical reagent and water softener, also used for purification of sugar.