Zein–natamycin functional films with ethylene adsorption and fungi stasis for active food packaging applications

Abstract

The main factors that lead to fruit spoilage are ethylene and microbial contamination. The majority of existing studies focus on single regulation tools for extending fruit shelf life, such as controlling ethylene concentration or inhibiting microbial contamination. The objective of this study was to fabricate zein–natamycin (Z-Nt) films that utilize the synergistic effect of zein and natamycin to extend the shelf life of fruits in terms of ethylene adsorption and microbial inhibition. The mechanical properties, contact angle, water vapor permeability (WVP), oxygen permeability (OP), ethylene adsorption efficiency, antimicrobial properties, and fruit preservation tests were used to characterize the performances of the Z-Nt films. As the natamycin content increased, the films presented an increase in contact angle and a decrease in WVP, indicating an increase in the hydrophobicity of the films. Furthermore, the natamycin content of the films is inversely proportional to OP and positively proportional to ethylene adsorption efficiency. The antimicrobial properties of the films were evaluated against Geotrichum candidum strain and Wickerhamomyces anomalus isolate. Inhibition of mold growth was observed for all natamycin-containing films. Thus, in the case of bananas, the film has a significant mitigating effect on the browning rate, weight loss rate, and hardness of bananas within a certain storage period. It can therefore be concluded that the film, as a bio-based material, has good application value for extending the shelf life of fruits and improving their storage quality.