Effective moisture diffusivity modelling versus food structure and hygroscopicity

摘要

Effective moisture diffusivities (D_(eff)) for model food systems presenting distinct structure and water sensibility were identified at various levels of hydration. Experimental moisture sorption kinetics with a controlled atmosphere microbalance were analyzed using distinct Fickian models with specific assumptions. Taking into account the deformation and the external resistance to mass transfer, higher values of D_(eff) were identified specially for hygroscopic dense products in the range of high water activity. The difference of impact of the model assumptions on D_(eff) depending on the investigated water activity range and food material was related to the structure and the equilibrium moisture sorption properties.