Sodium Citrate is the sodium salt of citric acid. Sodium citrate doesn't truly contain citric acid as much as it is citric acid, at least in a way. When you consume citric acid, it's in the form of citric acid in your acidic stomach, then becomes citrate in the more neutral environment of the intestines. Citrate, by comparison, becomes citric acid in the stomach, and then reverts to citrate in the intestine. As such, your body treats sodium citrate and citric acid identically.
NOTE: The 13 gram size bag offered is the specific measurement for the mac & cheese recipe published in the Cleveland Plain Dealer and online at Cleveland.com.
Other sizes are available on request.