ENZYMATIC-HYDROLYSIS OF CASEIN - EFFECT OF DEGREE OF HYDROLYSIS ON ANTIGENICITY AND PHYSICAL-PROPERTIES

Casein was enzymatically hydrolyzed for potential use in a hypoallergenic infant formula. Samples from the digest at different hydrolysis time (HT) intervals were tested for antigenicity, hydrophobicity, net charge (zeta potential), and emulsifying activity. Casein antigenicity loss could be approximated by three-phased first-order kinetics. Extensive antigenicity loss occurred during the first 10% of HT and relatively small changes occurred during the remaining 90% of HT. Hydrophobicity and emulsifying activity decreased, while the magnitude of the net charge increased (P <0.01) with increasing degree of hydrolysis. Strong correlations (r2 greater-than-or-equal-to 0.89) were found among hydrophobicity, emulsifying activity and zeta potential.