Effect of the calcium/protein molar ratio on β-lactoglobulin denaturation kinetics and fouling phenomena

Understanding the mechanism of whey protein fouling along a plate heat exchanger is a challenging issue in the dairy industry. The influence of the calcium/protein molar ratio on β-lactoglobulin (β-LG) denaturation and its consequence both on fouling mass along the plate heat exchanger and the structure of the fouling layer were studied. The experimental design was defined by varying the calcium/protein molar ratio from 2.3 to 22.9 and fixing the total concentration of calcium at 100 ppm. Results established that both the β-LG denaturation rate constants and the distribution of fouling in the plate heat exchanger were strongly impacted by the calcium/protein molar ratio. Structural analysis provided evidence that the fouling layer evolved from a thin and dense structure at low calcium/protein molar ratio towards a thicker and more open structure at higher calcium/protein molar ratio.