Kinetic release study of zinc from polylactic acid based nanocomposite into food simulants

Abstract

In the present study, the release of zinc (Zn) from polylactic acid/zinc oxid nanoparticles (PLA/ZnO NPs) nanocomposites to three aqueous food simulants (10% ethanol, 20% ethanol and 95% ethanol) was evaluated (during 15 days at 4, 25, and 40 °C) by atomic absorption spectrometry (AAS). The results indicated that temperature and the simulant type affected the migration of Zn and at a constant temperature; the maximum Zn release was observed in the 95% ethanol simulant. Pseudo-Fickian behavior was observed during the diffusion of Zn and diffusion coefficients (D values) of 0.002–6.08 10−11 cm2 s−1 were obtained in different migration conditions. The obtained partition coefficients (K) were between 21.66 and 0.057 μg g−1. The Zn release data were fitted with the Weibull model, and the b and n model parameters had values ranging from 0.008 to 0.07 and 0.24 to 0.49, respectively. The results of the present study indicated that Zn had little migration from PLA films into food simulants (especially in water at 4–40 °C) which was attributed to the high activation energy (Ea) values for Zn diffusion from PLA/ZnO NPs nanocomposites.