Carbon dioxide diffusion at different relative humidity through coating of cellulose nanocrystals for food packaging applications

In this paper, the investigation was focused on the CO2permeability through CNCs coating at various RH values, comparing with the O2one, aiming to evaluate the potential usage in all the applications of modified atmosphere packaging for intermediate-low moisture foods where the role of carbon dioxide is essential for shelf life extension. For this purpose, PET films were coated with characterized CNCs, obtained from cotton linters, and the CO2permeance was measured as a function of increasing RH values (from 0% to 80%). After calculating the diffusion and solubility coefficients, and estimating the CO2/O2selectivity, the possible evolution of different modified atmospheres has been theoretically calculated. The results obtained, let hypothesize that, in consequence of a very high CO2/O2permeability selectivity, the CNCs coated films can be useful in some modified atmosphere packaging applications, in a range of RH typical of many medium-high RH food products.