Active Packaging Based on Coupled Nylon/PE Pouches Filled with Active Nano-Hybrid: Effect on the Shelf Life of Fresh Milk

Abstract

The study reports on the preparation and characterization of an active packaging based on pouches composed of a coupled system nylon/polyethylene (PE). The PE layer was filled with and active nano-hybrid of layered double hydroxide (LDH) on which it was anchored salicylate, as antimicrobial molecule. The release of the salicylate anchored to the LDH was compared to the release of the molecule free dispersed into the PE and resulted much slower. It was evaluated the efficiency of the active packaging to inhibit Pseudomonas aeruginosa, Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Campylobacter. Global migration tests on the PE active layer, using ethanol (50% v/v) as food simulant, demonstrated the possibility of such active nanocomposite to be used for food contact being the migration limits in compliance with those imposed from the EU regulation. Fresh milk was packed into the active pouches and pouches with unfilled PE layer, as control. The pH reduction as function of the time, due to the production of lactic acid, resulted much slower in the active packaging. Total bacterial count (TBC) was evaluated on the milk, either packed into the active packaging or the control, up to 50 days of storage at 4 °C. Shelf life of the milk was evaluated using the Gompertz model. It was demonstrated an increasing of the shelf life of milk packaged in active pouches from 6 days up to 10 days.

Sodium Alginate–Soy Protein Isolate–Chitosan–Capsaicin–Nanosilver Multifunctional Antibacterial Composite Gel

“…Milk is a food that is extremely prone to spoilage and susceptible to bacterial contamination [51]. As shown in Figure 6, on the 6th day, the milk samples of S-C-L, S-A-L, and S-C-A gels showed a small amount of solid milk residue and yellow bacterial colonies on the surface of the milk, accompanied by a slight foul smell.…”

“…Additionally, AgNPs and -NH 2 might enter the cell wall and subsequently disrupt ion transportation channels [55]. The synthesis of enzymes might be disrupted, and proteins would be destroyed, resulting in bacterial inactivation [51,56]. In this study, a crosslinked network structure gel was constructed, and AgNPs were fully loaded into the network structure.…”

Kinetic and Thermodynamic Analyses of Co-Pyrolysis of Nylon-Polyethylene Pouch Wastes

“…Therefore, polymers used to make packaging plastic films are required to balance the packaging permeability requirements, the respiratory activities of the fresh foods and the surrounding temperature and humidity. Among these plastic films used, nylon-6/polyethylene (N-PE) double-layer films appear very attractive for preserving fresh foods [1,2] since their mechanical, thermal and gas-permeable properties complement each other [3]. With the rapid development of the food packaging industry and the demand for plastics, the accumulation of plastic waste has increased, and the environmental hazards thus caused have gained widespread concern around the world.…”