Analysis and modeling of potassium sorbate diffusion through edible whey protein films Original Research Article

The mechanism of potassium sorbate release from edible whey protein films was investigated. Anomalous or non-Fickian diffusion mechanism with diffusional exponents (n) between 0.55 and 0.86 were found. A model describing the diffusion of potassium sorbate from whey protein films that swelled due to countercurrent diffusion of solvent was used to determine potassium sorbate and solvent diffusion coefficients. The diffusivities of potassium sorbate at 25°C ranged from 5.38 to 9.76×10−11 m2/s, while those of the solvent from 1.29 to 7.43×10−10 m2/s, depending on film composition.