Comparing different methods for estimating kinetic parameters of whey protein heat-induced denaturation in infant milk formulas

Abstract

Modeling the heat-induced denaturation of milk proteins is a relevant issue because of heating processes in the manufacturing of several dairy products. In this study, four different parameter estimation methods were evaluated to estimate the kinetic parameters of the heat-induced protein denaturation of β-lactoglobulin (β-LG) and lactoferrin (LF) in infant milk formulas (IMF). The methods were: a two-step method, nonlinear least-squares (NLS), one-step linearized, and weighted least-squares (WLS). The WLS was the best alternative, avoiding biases observed when applying other methods besides producing consistently low residuals. Using the second proposed weight function, the WLS produced sum of squared errors and mean absolute percentage errors with average values of respectively 0.18 and 12.3% versus 0.27 and 13.3% considering all methods. However, the WLS requires good initial guesses for parameters, and previous knowledge of sampling and residuals variance. Those can be provided by previously performing the two-step and NLS methods, respectively.

Surface reaction kinetics of the methanol synthesis and the water gas shift reaction on Cu/ZnO/Al2O3

“…Common approaches are the inverse of squared experimental value, 45,46 the inverse of the squared simulated value, 47 or the inverse of experimental multiplied by simulated value. 48 Here, the inverse of the squared experimental value was used as weights. The function fminsearch from Matlab was used, and the objective function is shown as follows.…”

Effect of pH on Diclofenac–Lysozyme Interaction: Structural and Functional Aspect

“…T m and Δ H m were determined from these plots using Eq. 1 ( Santoro and Bolen, 1988 ; Sinha et al, 2000 ; Singh et al, 2007 ; Lin et al, 2020 ; Leite et al, 2021 ). The parabolic function (such as y N ( T ) and y D ( T )) for the analysis of the transition curve explains the dependence of the optical properties of the folded and unfolded protein molecules ( Islam, 2020 ; Parray et al, 2020 ; Parray et al, 2021 ).…”

“…T m and ΔH m were determined from these plots using Eq. 1 (Santoro and Bolen, 1988;Sinha et al, 2000;Singh et al, 2007;Lin et al, 2020;Leite et al, 2021).…”