Interactions between aroma and edible films. I. Permeability of methylcellulose and low-density polyethylene films to methyl ketones

This work contributes to the study of aroma transfers through edible and pl astic packaging films. Permeability, sorption, and diffusivity of three met hyl ketones (2-heptanone, 2-octanone, and 2-nonanone) in and through low-de nsity polyethylene and methylcellulose-based edible films have been determi ned. Permeability was measured using a dynamic method coupled with a gas ch romatograph. The methyl ketone permeability of polyethylene films mainly de pends on diffusivity of the penetrant in the polymer. In the case of 2-hept anone, a saturation of the polymer network is observed at high vapor concen trations. The formation of clusters could take place when concentrations ar e higher in the vapor phase. Physicochemical interactions between aroma com pounds and components of the methylcellulose-based film induce structural c hanges such as plasticization, Therefore, the diffusion step depends on the aroma concentration differential, and permeability is essentially driven b y the sorption.