Changes in Particle Size Distribution and Solubilisation of Casein Protein during Enzymatic Hydrolysis

The casein hydrolysates from enzymatic hydrolysis for 10, 20, 30, 40, 60, 80 and 100 minutes were prepared in the present study. The appearance structure, particle size distribution and solubility of casein hydrolysates were evaluated. Larger casein micelles tended to be the smaller during hydrolysis in the scanning electron microscopy images. Aggregation of hydrolysate was obtained after hydrolysis of 80 min and 100 min. The obvious decrease in D50, D (4,3) and D(3, 2) of casein hydrolysates was found compared with the native casein. There was a significant improvement in solubility of casein hydrolysates in water and in 0.1 M NaCl in all tested pH values (p<0.05). Moreover, the stability of casein proteins was also enhanced by enzymatic hydrolysis.