High-pressure can reduce the antigenicity of bovine whey protein hydrolysates

Resumen del póster presentado a la 4th NIZO Dairy Conference: "Prospects for health, well-being and safety", celebrada en Paises Bajos en junio de 2005.Infant formulas are widely used as supplements or substitutes to human milk when this is not sufficiently available. Most formulas are based on hydrolysates from bovine whey protein (WP) to correspond with infant nutritional requirements. Enzymatic proteolysis and heat treatment are normally used to reduce the α-lactoglobulin (α-LG) content and other intact proteins, in order to reduce the antigenicity of milk proteins. However, residual allergenicity in these commercial preparations has been reported, which could be due to inaccesibility of some epitopes to proteases even in the denatured protein. High pressure could form an alternative to heat treatment to unfold the intact protein and to increase the accessibility, since high pressure treatment (>200MPa) has shown to induce protein unfolding of monomeric proteins. The combination of enzymatic and HP treatments might have a practical relevance to decrease the immunoreactivity of proteins. In the current study, enzymes were selected for further evaluation: Alcalase, Neutrase, Corolase 7089 and Corolase PNL. WP hydrolysis was carried out at 50ºC for all enzymes, with the exception for corolase PNL (40ºC) for 15 min at 0.1 MPa and 100-300 MPa. The cleaved peptide bonds and RP-HPLC peptide profile were evaluated. An indirect ELISA test using polyclonal rat anti α-LG was used to determine the residual antigenicity. For two enzymes, Corolase PNL and Neutrase, differences in peptide profiles were obtained according to the pressure applied during the enzymatic hydrolysis. Based on these differences, the resiudal antigenicity of these preparations was determined, and it was found to be reduced. These results suggest that HP enhances the WP hydrolysis, and, depending on the choice of enzymes, reduces the residual antigenicity of the hydrolysates.Peer reviewe