Modification of edible chitosan/polyethylene glycol films fortified with date palm fruit waste extract as promising antimicrobial food packaging materials for fresh strawberry conservation

Abstract

In light of the global concern that calls for the safe disposal of waste polluting the environment and its exploitation in adding many distinctive products that can be used practically, this study was conducted to clarify how to make the best use of such waste. Therefore, the presented research aims to eliminate these residues and use their extracts as antimicrobial materials that can be used for films/membranes preparation for food and fruit preservations with low economic feasibility. Based on that, the aim of our work was planned to prepare films of date palm fruit waste extract (DPFW) loaded chitosan (Cs)/polyethylene glycol (PEG) composite. The extract was added to the polymers mentioned above with three different concentrations to prepare three film samples (DPFW-1@Cs/PEG), DPFW-2@Cs/PEG and DPFW-3@Cs/PEG). All these films were compared with those prepared without DPFW (DPFW-0@Cs/PEG). The film solutions films were cross-linked using glyoxal as a crosslinker before films formation. The finding illustrated that, the surface structure of DPFW-loaded Cs/PEG became rough, and the extract was remarkably seen on the surface of Cs/PEG films. In addition, the water contact angle for all fabricated films revealed that the films are hydrophobic in nature. The thermal stability of Cs/PEG films were enhanced with the addition of DPFW. The DPFW extract displayed an impressive suppression effect against the identified pathogens in antimicrobial experiments. As fresh strawberries were preserved using Cs/PEG film loaded with DPFW for 10 days, it was discovered that the strawberry wrapped in the extract-containing films maintained their freshness superior to those wrapped in unloaded material. Such films have a wide range of potential applications in food packaging to extend the longevity of freshly prepared goods due to their simplicity and solid biocidal ability. The present research's findings imply that DPFW-3@Cs/PEG material can be successfully used to pack perishable fruits and vegetables.