Other names for the additive (synonyms)
General Information
Monosodium phosphate (additive E339(i)) is a subtype of E339 (sodium phosphates) and is used in the food industry as an acidity regulator, emulsifier, and stabilizer.
Its chemical formula is NaH₂PO₄. Additive E339(i) is a crystalline or granulated white powder, highly soluble in water but almost insoluble in alcohol. Monosodium phosphate has a pronounced acidic reaction, which is why it is often used as an acidity regulator and buffering substance in food production.
In industry, additive E339(i) is obtained by reacting orthophosphoric acid with sodium hydroxide under specific conditions that yield the salt with one sodium atom in the molecule.
Due to its acidic nature, additive E339(i) is applied in the production of baking mixes, dairy products, beverages, and meat processing, where stable pH and slowed microbial growth are required.
Unlike other subtypes (E339(ii) and E339(iii)), monosodium phosphate is used where acidification or buffering with an acidic pH is needed. It plays a particularly important role in bakery and confectionery production, as well as in beverage manufacturing.
More details on the health effects of sodium phosphates, scientific studies, and legal regulations can be found in the main article on additive E339.