ABSTRACT
Phosphates, through their interactions with some of the constituents of food systems, have very useful and important functions in food processing. The treatment of water used in food processing is an important application of the metal-complexing ability of the phosphates. The cyclic condensed phosphates, sodium trimetaphosphate and sodium tetrametaphosphate, form very weak, complexes, if any, with metal ions of all types. The orthophosphates are capable of precipitating iron and similar transition metal ions. The polyphosphates, including those ranging from two to many phosphorus units per molecule, form complexes with nearly all of the metallic ions. The ability to form soluble complexes with metal ions apparently does not depend on the chain length of the polyphosphate, since complexes are reported for the pyrophosphates as well as for the long-chain polyphosphates. Some functions of phosphates in food processing depend on their ability to form complexes and reaction products with constituents of foods other than mineral elements.
