Novel packaging film for humidity-controlled manipulating of ethylene for shelf-life extension of Agaricus bisporus

A new polysaccharide multilayer biodegradable film was developed and tested, which can scavenge ethylene and inhibit ethylene action by releasing 1-methylcyclopropene (1-MCP). The film was fabricated with the stacking order of hydrophobic ethyl cellulose outer layer, a mixture of 1-methylcyclopropene and palladium on carbon (1-MCP-Pd/C) middle layer and hydrophilic hydrogel inner layer. The excess water produced by fruits and vegetables was absorbed by inner layer, avoiding the accumulation of condensed water. Meanwhile, the increase of the permeability of the inner hydrogel layer caused by moisture absorption facilitated manipulation of antistaling agent. SEM, TG and DSC proved that the functional components were successfully loaded on the film. Gas chromatography analysis results demonstrated that the 1-MCP release rate and ethylene removal rate could be controlled by adjusting the humidity (50% RH to 100% RH). The effects of the film on the main quality attributes of Agaricus bisporus were evaluated at 20 °C. This prepared functional film could delay the softening, browning and weight loss of mushrooms, maintain the integrity of mushroom cell membrane, maintain ascorbic acid content and soluble solid content, and inhibit the activity of ethylene synthesis-related enzymes.