Sodium citrate is the sodium salt of citric acid. In this sense, it is similar to calcium citrate. Like citric acid, sodium citrate has a sour taste, as well as having a salty taste, like other salts. For this reason, citrates such as sodium and calcium citrate are commonly known as sour salt (sometimes, people refer to citric acid as sour salt). It is chiefly used as a food additive, usually for flavor or as a preservative. Sodium citrate gives club soda and most lemon-lime soft drinks both their sour and salty flavors.
Used to control acidity and is an important part in the making of some spheres. Acts as an acid buffer- add to high acid liquids so gelling will work. It dissolves very easily and acts instantaneously. It can also stabilize emulsified fat.