A two competing substrates Michelis-Menten kinetics scheme for the analysis of in vitro starch digestograms

Abstract

Progress curves of enzymatic hydrolysis are commonly used for gaining insights on the structure and functionality of native and modified starch. Commonly, heuristic models (e.g., first-order kinetics) are used to fit the experimental data. Models derived from kinetics schemes provide valuable insights on the digestibility properties of starch. In this work, a two competing substrates Michaelis–Menten scheme with enzyme inhibition by-products is used for developing a structured model for enzymatic hydrolysis of starch dispersions. The resulting nonlinear model can provide estimates of the hydrolysis dynamics of rapidly and slowly digested starch fractions. The estimation of parameters is carried out by the numerical solution of a least-squares problem, and illustrated with the hydrolysis by 𝜶-amylase of gelatinized corn starch dispersions.