Polyphosphates
The short version
Chain phosphates — used to retain water in processed meat and seafood, increasing yield (and added water).
It's permitted and generally considered safe, but there are a few reasons to be mindful — like sensitivities in some people, debated studies, or intake limits. The Safety section below explains the specifics.
Where it comes from
Produced by thermal dehydration of orthophosphates, yielding chain or ring polymers of phosphate units. Sodium hexametaphosphate (the most common variant) was first characterized by Thomas Graham in 1834.
How it's used
Widely used in processed meats, seafood, and poultry (≤0.5%) to bind water and increase product weight — a controversial practice that effectively dilutes meat with added water. Also in processed cheese, energy drinks, and as a sequestrant elsewhere.
Safety profile
ADI of 70 mg/kg body weight as phosphorus (combined phosphates). The added-water-via-polyphosphate practice has consumer-transparency concerns separate from the phosphate-load concern. Mandatory declaration of added water in some jurisdictions.
Physical & chemical properties
White crystalline or glassy powder, very soluble in water. Strong sequestrant of calcium and trace metals. Hydrolyzes slowly to shorter chain phosphates in solution.
Regulation worldwide
Permitted globally with strict maximum levels per category. Some jurisdictions require disclosure of added water percentage when polyphosphates are used.
Educational information only. Not medical or dietary advice.