Effect of Succinylation on the Rennet Coagulation of Milk

Abstract

The effects of succinylation on the rennet coagulation of milk were investigated to find a relationship between the level of chemical modification and the ability of milk protein to coagulate. The strengthening rate and the final firmness of the gel decreased as the extent of succinylation increased, which could be related to the microstructural differences caused by milk succinylation. The kinetics of nonprotein N release were not affected by milk succinylation, but the rennet clotting time increased as the extent of chemical modification increased. These results suggest that milk succinylation affected the secondary or aggregation phase of enzymatic coagulation by increasing the electrostatic repulsions between paracasein micelles and, more indirectly, by dissociating casein from micelles and preventing them from participating in network formation of the gel.