E451: Pentasodium triphosphate

What is E451?

E451i is pentasodium triphosphate, also known as sodium tripolyphosphate, a salt built from three linked phosphate units. It is a white powder that binds metal ions and interacts strongly with proteins.

Origin and production

It is manufactured from purified phosphoric acid, usually derived from phosphate rock, which is neutralised with sodium compounds and heated to form the triphosphate. It is entirely mineral in origin.

Why is it used?

In meat products, triphosphates help proteins hold water, improving juiciness and yield and reducing cooking losses; they also act as sequestrants and stabilisers. Pentasodium triphosphate is common in cooked ham, sliced chicken breast, cured sausages and other processed meats, and in instant noodles to improve texture.

Vegan, vegetarian and halal

E451i is a mineral salt, so the additive itself is suitable for vegans and vegetarians and raises no specific halal or kosher concerns. However, it is very often used in meat products, which need to be judged on their own.

Safety and regulation

Pentasodium triphosphate is authorised as a food additive in the European Union and was included in EFSA's 2019 re-evaluation of phosphates, which set a group acceptable daily intake for phosphorus from phosphate additives. It is also permitted in many other countries.

Common in