Inhibitory effect of protein hydrolysates on calcium carbonate crystallization

Protein hydrolysates, prepared by enzymatic digestion of soybean protein an d egg white albumin using several proteases, inhibited the crystal growth o f calcium carbonate. Each hydrolysate showed different inhibitory activitie s, suggesting the key role of peptide structures in the inhibition,The deam idation of protein hydrolysates by glutaminase increased not only the inhib itory activity toward the crystal growth of calcium carbonate but also the resistance of the hydrolysates against peptic digestion. Furthermore, the a ddition of sodium chloride, citric acid, or lactose into the reaction mixtu re enhanced the inhibitory activity. The protein hydrolysates inhibited bot h nucleation and crystal growth of calcium carbonate and also affected the crystal morphology.