The reduction of cow milk proteins immunoreactivity by two-step enzymatic hydrolysis

Commercial sodium caseinate isolate (SCI) was hydrolysed with either protease Subtilisina carlsberg - Alcalase 2.4 FG (purchased from Novo Nordisk), pronase from Streptomyces griseus, and papain EC 3.4.22.2 (both from Sigma) in a two-step process to determine the changes in the immunoreactivity of a-, ß- and ?-casein. Enzymatic hydrolysis of SCI was performed by pH-stat method. Hydrolysates were analysed using IEF, SDS-PAGE, 2D electrophoresis, FPLC-gel permeation chromatography. Immunoreactive properties of peptide fractions separated from the hydrolysates by FPLC were determined using dot-immunobinding and ELISA methods. The two-step process was observed to be effective in reduction of casein fractions immunoreactivity, however, allergenic epitopes were still present in all peptide fractions