Drying and Denaturation Kinetics of Beta-Lactoglobulin during Convective Drying

Beta-Lactoglobulin (β-Lg) is the largest protein fraction of whey proteins comprising more than 65%. Being the major fraction, it determines many of the unique properties of whey proteins. Thus, the denaturation of β-Lg during drying can limit the application of whey proteins as ingredient. This study was carried out to measure and predict the drying and denaturation kinetics of β-Lg during drying at droplet level in a convective drying environment. The moisture content and temperature scenarios during the drying process were predicted using reaction engineering approach (REA¬)-based model. The REA-predictions were coupled with the first order reaction kinetics to predict the denaturation kinetics. Single droplets of β-Lg (10% w/v; 1.5±0.1 mm initial diameter) were used throughout drying experiments carried out at two temperatures (65 °C and 80 °C) at a constant air velocity (0.5 m/s) for 10 minutes. There was a good agreement between the experimental data and the REA predictions. The model predictions fitted the experimental data with ±5.70% and ±3.50% error for moisture-time and temperature-time profiles, respectively. A combination of the REA-based model with first order kinetics model was also successful in predicting the denaturation kinetics.