Potassium Benzoate
What it does
Antimicrobial preservative.
How it's made
Potassium salt of benzoic acid.
Potassium benzoate is the potassium salt of benzoic acid, used as a preservative against yeasts, moulds and bacteria in acidic foods and drinks, much like sodium benzoate. It provides a soluble form of the benzoate preservative for products where potassium is preferred over sodium.
It is produced by neutralising benzoic acid (made by oxidising toluene) with a potassium base such as potassium hydroxide or potassium carbonate, forming the soluble potassium salt, which is then purified.
The salt is dried into a white powder or granules. Like the other benzoates it works only in acidic conditions, where it releases active benzoic acid, and it is chosen when a manufacturer wants the benzoate preservative effect while keeping sodium levels down.
Possible reactions
Like other benzoates, may affect asthmatics and combine with vitamin C to form trace benzene.