Studies of polyphosphate composition and their interaction with dairy matrices by ion chromatography and 31P NMR spectroscopy

The use of ion-exchange chromatography and 31P nuclear magnetic resonance (31P NMR) to analyse the composition and the chain length of phosphate emulsifying salts were studied, as well as the impact of these salts in dairy products. Ion chromatography was more appropriate than 31P NMR to study polyphosphate composition in complex environments, whereas interactions between phosphate species and dairy components were elucidated by 31P NMR. Phosphate species interacting with calcium, as well as the percentage of chelated calcium, were identified using 31P NMR. Thus, ion chromatography and solid-sate 31P NMR could be used as complementary methods to study compositions of polyphosphate blends and their interactions with dairy matrices.