IN-VITRO HYDROLYSIS BY PANCREATIC ELASTASE-I AND ELASTASE-II REDUCES BETA-LACTOGLOBULIN ANTIGENICITY

Bovine whey proteins such as alpha-lactalbumin and beta-lactoglobulin are with bovine caseins the most commonly used proteins in infant form ulas owing to their high nutritional value. However, these cow milk co mponents are not always well tolerated and can induce allergies in inf ants. The purpose of this study was therefore to investigate the gastr ic (pepsin) and pancreatic (trypsin, chymotrypsin and elastases I and II) enzymatic hydrolysis of beta-lactoglobulin with the aim of finding a means to reduce its antigenicity. Elastases I and II were first pur ified from porcine pancreatic acetone powder. After differential preci pitation steps, elastases I and II were separated by cation-exchange c hromatography. The conditions regarding beta-lactoglobulin hydrolysis by gastric and/or pancreatic enzymes were similar to those used for hy poallergenic milk preparations. Elastase II and to a lesser extent ela stase I, were effective in enhancing beta-lactoglobulin hydrolysis via a mix of pepsin, trypsin and chymotrypsin and in reducing the residua l antigenicity of hydrolytic products. The same hydrolytic percentage was observed when elastase I or II were added, while the residual anti genicity was lower in the presence of elastase II than in the presence of elastase I. The introduction of elastases in the pancreatic mix ca n therefore be proposed to enhance the hydrolysis of cow milk componen ts in hypoallergenic milk preparations.