What is sodium citrate?

Sodium citrate is a mild alkali sodium salt of citric acid. It's used to regulate acidity in processed foods. The additive also acts as an emulsifier to prevent cheese from becoming greasy when melted. Sodium citrate holds the fat and water together, resulting in a smooth melted cheese. Sodium citrate is commonly used cheese sauces, jam, and ice cream, among other packaged food items.