Effect of calcium chelators on heat stability and heat-induced changes of milk microfiltered concentrates

Abstract

In this work, the effect of different calcium chelators on the heat stability of fresh microfiltered concentrates was investigated, by measuring the heat coagulation time (HCT) and pH, particle size, turbidity and viscosity of the dispersions after heat treatment. Samples in all conditions tested were stable with no visible coagulation when heated at 120 °C, for at least 20 min, and the highest values of HCT were observed at the original pH, 6.7. A stability peak was observed when a combination of citrate and phosphate at 15 mEq L−1 was added to the concentrates. Higher concentration of chelating salts decreased the heat stability of the dispersions. These results clearly demonstrated that fresh milk protein concentrates could be employed as ingredients for the development of new and improved dairy protein drinks, and that their stability behaviour showed profound differences compared with that reported for reconstituted milk protein concentrates of similar composition.