Biomass-based edible film with enhanced mass barrier capacity and gas permeable selectivity

Abstract

Edible films with desired mass transport properties have been receiving much attention for commercial packaging. In this paper, a modified nanofiltration setup using dialysis membrane was developed for the preparation of biomass-based edible (BE) film. The prepared films are effective barriers to oxygen by discriminating the molecular size and relative affinity between gas and film polymer matrix. Compared to the control film (co-blended film without the use of modified nanofiltration setup), the BE film possessed an enhanced gas/water vapor barrier effect and mechanical strength. In addition, the gas permeable selectivity [permeability ratio of CO₂–O₂ (${{{\text{P}}_{{({\text{CO}}_{2} )}} } \mathord{\left/ {\vphantom {{{\text{P}}_{{({\text{CO}}_{2} )}} } {{\text{P}}_{{\left( {{\text{O}}_{2} } \right)}} }}} \right. \kern-0pt} {{\text{P}}_{{\left( {{\text{O}}_{2} } \right)}} }}$)] was improved, which is beneficial for inhibiting the respiration rate. This was further confirmed by the fruits [Apricots (cv. Beijing Crystal)] respiration experiments. SEM results revealed a more uniform and smooth surface of the BE film with a compact lamellar cross section structure caused by the suction effect of the dialysis membrane. An increased optical transmittance (T₆₀₀) and decreased swelling capacity were further obtained.

Graphical abstract

Three-dimensional modeling of schematic diagram for the enhanced gas selectivity (${{{\text{P}}_{{({\text{CO}}_{2} )}} } \mathord{\left/ {\vphantom {{{\text{P}}_{{({\text{CO}}_{2} )}} } {{\text{P}}_{{\left( {{\text{O}}_{2} } \right)}} }}} \right. \kern-0pt} {{\text{P}}_{{\left( {{\text{O}}_{2} } \right)}} }}$) of the BE film is presented, and the pore-suction layer is the functional layer. A modified nanofiltration setup was developed by using dialysis membrane for the preparation of biomass-based edible (BE) film. The prepared film, constitutes of methylcellulose (continuous phase) and cellulose nanocrystals (discontinuous phase), has a compact lamellar cross section structure with improved optical transmittance (T₆₀₀). The BE film can be appraised as an effective barrier to mass transportation by discriminating the molecular size and relative affinity between the gas and polymer matrix. The improved mechanical strength/gas permeable selectivity [permeability ratio of CO₂–O₂ (${{{\text{P}}_{{({\text{CO}}_{2} )}} } \mathord{\left/ {\vphantom {{{\text{P}}_{{({\text{CO}}_{2} )}} } {{\text{P}}_{{\left( {{\text{O}}_{2} } \right)}} }}} \right. \kern-0pt} {{\text{P}}_{{\left( {{\text{O}}_{2} } \right)}} }}$)] is beneficial for modifying the package’s quality and its headspace atmosphere.