Immunoreactive properties of peptide fractions of cow whey milk proteins after enzymatic hydrolysis

Abstract

Abstract Commercial whey protein concentrate (WPC) was hydrolysed with either Alcalase 2.4 FG (Novo Nordisk), or papain (Sigma) (in one-step process) or with two enzymes (in two-step process) to determine the changes in the immunoreactivity of α-lactalbumin and β-lactoglobulin. Enzymatic hydrolysis of WPC was performed by pH-stat method. Hydrolysates were analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis, immunoblotting and size-exclusion chromatography (SE-HPLC). Immunoreactive properties of peptide fractions separated from the hydrolysates by fast protein liquid chromatography (FPLC) were determined using dot-immunobinding and enzyme-linked immunosorbent assay (ELISA) methods. Finally the sensory analysis was used to confirm organoleptic changes resulting from the application of different enzymes. The ‘two-step’ process was observed to be the most effective however allergenic epitopes were still present, as it was found by ELISA with anti-α-la and anti-β-lg antibodies. The addition of papain as the second enzyme in the hydrolysis process contributed to the improvement of the sensory properties of WPC hydrolysate as compared with the Alcalase hydrolysate. Alcalase-papain partially hydrolysated WPC can be found a promising base for production of the tolerogenic formula.