Heat treatment effect on polyphosphate chain length in aqueous and calcium solutions

Polyphosphate blends are used in food such as meat and dairy products to improve their texture and stability by sequestering metal ions. This study aims to analyse the impact of high temperature treatments on the composition of polyphosphates with regards to phosphate chain length in aqueous solutions with or without calcium. Temperature treatments of 120 °C for 10 min led to the hydrolytic degradation of long-chain phosphates into orthophosphate and trimetaphosphate whereas heating the salts to 100 °C in aqueous solutions had little effect on their composition. The presence of calcium increased the hydrolysis rate of long-chain phosphates and led to more trimetaphosphate and pyrophosphate as end products. The evolution of emulsifying salts’ composition under heat treatment may lead to a modification of their chelating properties since short-chain phosphates are less efficient to chelate calcium than long-chain phosphates.