Polycitra

Potassium citrate (also known as tripotassium citrate) is a potassium salt of citric acid with the molecular formula K3C6H5O7. It is a white, hygroscopic crystalline powder. It is odorless with a saline taste. It contains 38.28% potassium by mass. In the monohydrate form, it is highly hygroscopic and deliquescent. As a food additive, potassium citrate is used to regulate acidity, and is known as E number E332. Medicinally, it may be used to control kidney stones derived from uric acid or cyst... [wikipedia]