Eugenol@Montmorillonite vs. Citral@Montmorillonite Nanohybrids for gelatin-based extruded, edible, high oxygen barrier, active packaging films

Kechagias, Achilleas; Leontiou, Areti A.; Oliinychenko, Yelyzaveta K.; Stratakos, Alexandros Ch.; Zaharioudakis, Konstatninos; Proestos, Charalampos; Giannelis, Emmanuel P.; Chalmpes, Nikolaos; Salmas, Constantinos E.; Giannakas, Aris E.

Abstract

In the context of the circular economy, the valorization of bio-derived waste has become a priority across various production sectors, including food processing and packaging. Gelatin (Gel), a protein which can be recovered from meat industry byproducts, offers a sustainable solution in this regard. In this study, pork-derived gelatin was used to develop novel edible active packaging films, designed for meat products. Glycerol (Gl) was used as a plasticizer. Two types of montmorillonite-based nanohybrids were employed as both reinforcing agents and carriers of antioxidant/antibacterial compounds: eugenol-functionalized montmorillonite (EG@Mt) and citral-functionalized montmorillonite (CT@Mt). The active films were formulated as Gel/Gl/xEG@Mt and Gel/Gl/xCT@Mt, where x = 5, 10, or 15 wt.%. Controlled-release kinetics showed that EG@Mt released up to 95% of its adsorbed eugenol, whereas CT@Mt released up to 55% of its adsorbed citral. The films were evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and tested for antibacterial activity against Escherichia coli and Listeria monocytogenes. Results demonstrated that the Gel/Gl/xEG@Mt films exhibited superior antioxidant and antibacterial performance compared to the Gel/Gl/xCT@Mt films. All formulations were impermeable to oxygen. Although the incorporation of EG and CT slightly reduced cell viability, values remained above 80%, indicating non-toxicity. In conclusion, the film containing 15 wt.% EG@Mt achieved an oxygen transmission rate of zero, an effective concentration (EC60) of 9.9 mg/L to reach 60% antioxidant activity, and reduced E. coli and L. monocytogenes populations by at least 5.8 log CFU/mL (p < 0.05), bringing them below the detection limit. Moreover, it successfully extended the shelf life of fresh minced pork by two days.

• Journal Article Type: Article
• Acceptance Date: May 28, 2025
• Online Publication Date: May 29, 2025
• Publication Date: May 29, 2025
• Deposit Date: Jun 18, 2025
• Publicly Available Date: Jun 19, 2025
• Journal: Polymers
• Electronic ISSN: 2073-4360
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 17
• Issue: 11
• Article Number: 1518
• DOI: https://doi.org/10.3390/polym17111518
• Keywords: edible packaging, minced pork, montmorillonite, citral, active packaging, shelf life, eugenol, gelatin, high oxygen barrier
• Public URL: https://uwe-repository.worktribe.com/output/14564396