EFFECT OF PROTEIN CONCENTRATION ON KINETICS OF WATER VAPOUR ADSORPTION BY COATINGS PREPARED ON THE BASIS OF WHEY PROTEIN ISOLATE

The objective of the study was to determine the effect of whey protein content amounting to 7 - 10 % in a coating-forming solution on the kinetics of water vapour adsorption by whey coatings formed on the basis of whey protein isolate. The adsorption process was conducted for 20 h in an environment with 75.3 % of relative humidity. The effect of protein on the water vapour adsorption was analyzed by tracing the kinetic curves as a function of time and the water vapour adsorption rate curves as a function of water content. The dependencies between the increases in water content as a function of time were mathematically analyzed and the kinetic curves were described using an exponential equation. The analysis of the equation parameters obtained proved that they very well corresponded to the experimental data. Based on the analysis performed, the effect was shown of the protein content on water vapour adsorption by whey coatings.