Multiple-factor mathematical modeling of glycine-glucose browning

The objective of this investigation was to develop the mathematical models that included the effects of time, temperature, pH and substrate concentration on the non-enzymatic browning reaction. Glycine-glucose solutions were used as food models. Experimental data of 420-nm browning absorbance, which were converted into s-curved Xt values, were used for the modeling and validation processes. The impacts of multiple factors on browning were well expressed by a combined use of modified Gompertz, Arrhenius and interaction polynomial models and a data conversion technique (R2 ≥ 0.9441). The browning rates varied greatly (λ = 7.46–888 min and umax = 0.06 to 26.90 min−1), depending on temperature, pH and concentration. The activation energy (Ea) values of λ (62–120 kJ/mol) and umax (87–129 kJ/mol) varied, depending more on concentration than pH. Although non-enzymatic browning reactions are complex with a variety of pathways and reactive products in response to multiple factors, they are likely modellable so that the benefits (food quality based on color and aroma) and harmful properties (e.g., carcinogens) of browning can be better managed.