SELECTIVE HYDROLYSIS OF MILK-PROTEINS TO FACILITATE THE ELIMINATION OF THE ABBOS EPITOPE OF BOVINE SERUM-ALBUMIN AND OTHER IMMUNOREACTIVE EPITOPES

Milk proteins are hydrolyzed to prevent immunological reactions, but i mmunoreactive epitopes, including the ABBOS epitope of bovine serum al bumin (BSA), can still be detected in commercially available milk prot ein hydrolysates. We used lactococcal cell-envelope proteinase (CEP) f or the hydrolysis of the individual milk proteins and of mixtures ther eof, or for the hydrolysis of sodium caseinate (contaminated with whey proteins). CEP exclusively degraded casein, leaving the four major wh ey proteins intact. This property facilitated the removal of the intac t whey proteins from the casein fragments by ultrafiltration. Dependin g on the molecular mass of the whey protein to be removed, membranes w ith cutoff values between 3 and 30 kDa were used, resulting in casein hydrolysates free of protein fragments with cross-reactive whey-protei n-specific IgE (immunoglobulin E) or ABBOS antibody-binding sites. Eve n the casein itself was degraded in such a way by CEP that cross-react ive casein-specific IgE antibody-binding sites could be eliminated. Th e product could find application in infant formulas for therapeutic an d preventive treatment of children with cow's milk allergy; in additio n, the preventive use of such formulas in children genetically suscept ible to the development of insulin-dependent diabetes mellitus (IDDM) should be considered if a relationship between the consumption of BSA and IDDM were to become more apparent. The method is also applicable f or preparing casein-free whey protein preparations.