Preparation of a multilayer antibacterial film and its application for controlling postharvest disease in temperate fruit (including apple, pear, and peach) under ambient storage

Abstract

The objective of this study was to provide formulation of a new multilayer antibacterial film and to investigate the optimal use concentration of chitosan and carboxymethyl cellulose in the range from 0.5% to 2%, as well as its application for controlling postharvest disease in temperate fruit (apple, pear, and peach). The multilayer antibacterial film used chitosan (CS) and carboxymethyl cellulose (CMC) as polysaccharide macromolecule, lemon essential oil (LEO) as active agent, and ε‐polylysine (ε‐PL) as the main antibacterial ingredient. The results showed that the physical properties of the self‐assembled film were adjusted by the electrostatic layer‐by‐layer (LbL) deposition. Fourier transform infrared (FT‐IR) analysis and thermogravimetric (TGA) revealed that hydrogen bonds were generated during the self‐assembly of CS‐LEO/CMC‐ε‐PL film, resulting in changes in intermolecular interactions and thermal stability. Furthermore, compared with CS‐LEO single‐layer film, the multilayer film exhibited higher retention rate of LEO. In vivo test, the self‐assembled film significantly inhibited the infection of postharvest pathogenic fungi including Penicillium expansum (P. expansum) and Alternaria alternata (A. alternata) on fruit. To summarize, the CS‐LEO/CMC‐ε‐PL LbL self‐assembly coating notably controlled postharvest pathogen rot on fruit, and reduced the loss of fruit during storage and transportation. Our results suggest that the polysaccharide‐based edible coating prepared in this work may offer an alternative to synthetic waxes.

Innovative Systems for the Delivery of Naturally Occurring Antimicrobial Volatiles in Active Food-Packaging Technologies for Fresh and Minimally Processed Produce: Stimuli-Responsive Materials

“…Moreover, bioactives can be incorporated into polymeric matrices to enhance their antimicrobial activity. For example, lemon essential oil and ε-polylysine were added to chitosan and carboxymethyl cellulose to form a multilayer material, and the volatile retention was higher on bilayer films than those with the chitosan–lemon essential oil, showing a reduction in their diffusion rate and losses caused by the volatility [ 73 ]. The effectiveness of these films was tested on apples, pears, and peaches.…”

“…Polymer concentrations between 0.5 and 3% ( w / v ) were evaluated. The antimicrobial effectiveness improved by increasing the polymer content; however, the authors reported that using polymer concentrations above 1.5% ( w / v ) resulted in films with bad properties [ 73 ]. LBL has been also employed to control the release of bioactives; thus, thyme essential-oil microcapsules were developed combining chitosan and sodium alginate with several different amounts of layers (0, 2, 4, and 6).…”

Application of Carboxymethyl Cellulose and Its Edible Composite Coating in Fruit Preservation

“…A multi-layer antimicrobial film composed of chitosan and CMC as polysaccharide macromolecules, lemon EO as the active agent and ε-polylysine as the primary antibacterial component is applied for postharvest preservation of apples, peaches and pears. This coating effectively controls fruit decay caused by Penicillium expansum and Alternaria alternata [105]. In addition to improving the properties of the coating, the combination of the physical method and the coating can also effectively maintain the quality of the fruit.…”