Optimization by an orthogonal array design of deep hydrolysis of bovine milk whey proteins and caseins to reduce allergenicity

Bovine milk (BM) is a common nutrient-rich food, but also a potential allergen for infants with milk allergy. In this study, a method for the preparation of deeply hydrolyzed whey proteins or caseins (DH-WP and DH-CN, respectively) was proposed and residual antigenicity was assessed. The optimal conditions for preparation of DH-WP were hydrolysis with flavorzyme for 5 h at 55°C, pH 6.5, and an enzyme–substrate ratio (E/S) of 10,000 U/g, whereas those for DH-CN were hydrolysis with neutrase for 4 h at 50°C, pH 7, and an E/S of 10,000 U/g. The relative contents of peptides (<3 kDa) in the DH-WP and DH-CN products were 99.20% and 98.34%, respectively. The sensitization assessment, RBL-2H3 cell model, and peptidomics analysis indicated that the major allergens in obtained DH-WP and DH-CN were basically eliminated and the sensitization was significantly reduced. This study provides a theoretical basis and technical support for the application of DH-WP and DH-CN in hypoallergenic infant formula.