Dextran/chitosan blend film fabrication for bio-packaging of mushrooms (Agaricus bisporus)

Agaricus bisporus is likely the most worldwide consumed mushroom, however, its commercial acceptability requires an attractive visual appearance for the consumer. The storage is an essential stage in controlling the physical appearance and shelf-life of the mushrooms. In this study, films based on commercial chitosan and a dextran produced by a Leuconostoc mesenteroides strain, were fabricated and then proposed to replace commercial packing materials. The dextran/chitosan blend films were evaluated according to the dextran concentration variation (from 0.0 up to 4.0% w/v dispersion), their physicochemical, mechanical and permeability characteristics, and their functionality in the bio-packaging of mushrooms. The results showed that the lowest dextran concentration (0.5% w/v dispersion) presented the best properties for tensile strength (2.32 MPa), elastic modulus (~6.54 MPa), water vapor permeability (4.09 g mm kPa⁻¹ m⁻² hr⁻¹), and delayed spoilage time of mushrooms up to 28 days at 4°C. Our findings demonstrate that these biofilms can be a viable bio-packaging alternative for preserving fresh mushrooms. Novelty impact statement: In this work, we have developed new sustainable biopolymers-based films using chitosan and dextran. The latter material was produced through biotechnological approaches using Leuconostoc mesenteroides SF3. The developed biofilms were fully characterized and later tested for the preservation of mushrooms over 28 days. Based on our findings, the application of the dextran/chitosan blend films can be viable as a bio-packaging alternative for preserving fresh mushrooms, extending their storage and quality.