Sodium Citrate
What it does
Acidity regulator, emulsifier.
How it's made
Made from citric acid.
Sodium citrate is the sodium salt of citric acid, and it is a real multitasker: it regulates acidity, acts as an emulsifying salt that keeps cheese smooth when melted, binds trace metals to protect flavour and colour, and even serves as the anticoagulant that stops donated blood from clotting. In food it gives a mild, slightly salty-sour taste.
It is produced by neutralising citric acid — made by the fermentation of sugars with Aspergillus niger — with a sodium base such as sodium hydroxide or sodium carbonate. By controlling how much base is added, manufacturers can make the mono-, di- or trisodium salt, with trisodium citrate being the most common food form.
After neutralisation the solution is purified, concentrated and crystallised or spray-dried to a white powder or granules. Because it starts from food-grade citric acid and a food-grade alkali, the finished salt is very pure, and its exact grade is chosen to suit the job, whether that is processed cheese, soft drinks or preventing discolouration in prepared foods.
Possible reactions
Generally safe.