A mathematical model for the enzymatic hydrolysis of biopolymers was proposed. The model was used to determine the quantitative and qualitative composition of a reaction mixture. Assumptions of the model were characterized, model parameters were defined and a method for their determination was specified. The model was positively verified using the data obtained for beta-lactoglobulin and trypsin. Independent of the kind of kinetic equation, the model allows choice of such a reaction time in which the desired decomposition of the fractions is achieved. (C) 2015 Elsevier B.V. All rights reserved.