Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The mechanism of potassium sorbate (K-sorbate) release from chitosan films was studied as a function of immersion time in aqueous solution. Fick's law was applied to calculate the diffusion coefficient and the power law defining the type of diffusion mechanism. The novelty in this study is the compound diffusion mechanisms comparison through chitosan film (CF) and chitosan emulsion film Initially, the lipid was selected to obtain the emulsion films The evaluation was based oil the water vapor permeability (WVP) The lower WVP (32.45% less than chitosan film) Was found using 0 5 g/100 g of palmitic acid for 2.0 g/100 g of chitosan Then, active chitosan films (ACF) were obtained incorporating K-sorbate on CF at 0 1 and 0 5 g/100 g of K-sorbate Also, active palmitic acid-chitosan films (APEF) were obtained, incorporating 0 1 g/100 g of K-sorbate The mechanisms of K-sorbate diffusion through ACF and APEF were mainly non-Fickian. However, the K-sorbate diffusion coefficient did not reduced in lipid presence (C) 2009 Elsevier Ltd All rights reserved.434584589Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)ALFA [II-0259-FA-FDC]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)ALFA [II-0259-FA-FDC]