Enzymatic characterisation of the immobilised Alcalase to hydrolyse egg white protein for potential allergenicity reduction

BACKGROUND This study examined technique characteristics of the immobilised Alcalase to hydrolyse egg white protein for potential allergenicity reduction. Alcalase was immobilised covalently on carboxyl-functionalised magnetic beads by carbodiimide activation. The technique characteristics of the immobilised Alcalase were investigated, followed by determining the degrees of hydrolysis (DH), immunoglobulin G (IgG) binding, and IgE binding of the digested egg white protein by immobilised Alcalase. RESULTS Enzymatic activity, enzyme loading, and immobilisation yield of the prepared immobilised Alcalase were 20.55 U mg −1 , 925 mg g −1 , and 45%, respectively. Immobilised Alcalase showed maximum activity at pH 8.0 and 60 °C. Compared with free Alcalase, immobilised Alcalase exhibited better thermal and storage stability. Moreover, immobilised Alcalase can be reused 10 times and still maintained 55% of its initial activity. Partial hydrolysis of egg white protein by immobilised Alcalase can effectively reduce IgG and IgE binding of the hydrolysates. CONCLUSION This study indicates that the immobilised Alcalase can be used to hydrolyse continuously egg white protein for potential allergenicity reduction. © 2016 Society of Chemical Industry