Mathematical Assessment of Carbohydrate and Protein Profiles of Milk under Thermal Stress

The dairy industry needs new methods for food quality assessment at all stages of production and storage. Mathematical methods offer efficient tools of product quality control. This article introduces a mathematical approach to assessing the kinetics of protein and carbohydrate profiles of milk powder to predict their transformations throughout production and storage. The study featured milk at different processing temperatures and exposure times. The analysis focused on the concentrations of compounds that mark the changes in the carbohydrate and protein profiles of milk during heat treatment. The equation of pseudo-zero-order and the Arrhenius equation were applied to carbohydrates while a first-order equation made it possible to assess the changes in proteins. The calculation algorithm was processed in Python. The lactulose, hydroxymethylfurfural, and furosine accumulations proved to depend on the integral heat load. The activation energies that provided the linearity maximum were as follows: 130 kJ/mol for lactulose and furosine; 85 kJ/mol for hydroxymethylfurfural. The calculation model failed to assess the accumulation of carbohydrate profile products during prolonged thermal exposure due to more profound product changes. β-lactoglobulin appeared to be more susceptible to thermal effects than α-lactalbumin. The activation energies for whey proteins were 72.1 and 85.1–85.7 kJ/mol, respectively. The new mathematical approach provided a reliable quantitative assessment of thermal stress that can be used for food quality control and shelf-life adjustments, e.g., in milk powder production.