Journal Article

Antibacterial Biodegradable Films Based on Alginate with Silver Nanoparticles and Lemongrass Essential Oil–Innovative Packaging for Cheese

Ene, Vladimir-Lucian, Motelica, Ludmila, Holban, Alina-Maria, Ficai, Denisa, Oprea, Ovidiu-Cristian, Andronescu, Ecaterina, Ficai, Anton, Vasile, Bogdan-Stefan

2021

Overview

Replacing the petroleum-based materials in the food industry is one of the main objectives of the scientists and decision makers worldwide. Biodegradable packaging will help diminish the environmental impact of human activity. Improving such biodegradable packaging materials by adding antimicrobial activity will not only extend the shelf life of foodstuff, but will also eliminate some health hazards associated with food borne diseases, and by diminishing the food spoilage will decrease the food waste. The objective of this research was to obtain innovative antibacterial films based on a biodegradable polymer, namely alginate. Films were characterized by environmental scanning electron microscopy (ESEM), Fourier-transform infrared spectroscopy (FTIR) and microscopy, complex thermal analysis (TG-DSC-FTIR), UV-Vis and fluorescence spectroscopy. Water vapor permeability and swelling behavior were also determined. As antimicrobial agents, we used silver spherical nanoparticles (Ag NPs) and lemongrass essential oil (LGO), which were found to act in a synergic way. The obtained films exhibited strong antibacterial activity against tested strains, two Gram-positive (Bacillus cereus and Staphylococcus aureus) and two Gram-negative (Escherichia coli and Salmonella Typhi). Best results were obtained against Bacillus cereus. The tests indicate that the antimicrobial films can be used as packaging, preserving the color, surface texture, and softness of cheese for 14 days. At the same time, the color of the films changed (darkened) as a function of temperature and light presence, a feature that can be used to monitor the storage conditions for sensitive food.

• Publisher: MDPI AG,MDPI
• Subject: alginate film / Alginates / Alginic acid / Antibacterial activity / antibacterial packaging / Antimicrobial activity / Antimicrobial agents / Bacillus cereus / Biodegradability / biodegradable / Biodegradable materials / Biodegradation / Cellulose / Cheese / Color / Dairy products / E coli / edible packaging / Environmental impact / Essential oils / Fluorescence / Fluorescence spectroscopy / Food industry / Food packaging / Food spoilage / Food waste / Foodborne diseases / Fourier transforms / Glycerol / Hazard mitigation / Health hazards / Human influences / Humidity / Infrared analysis / Infrared spectroscopy / lemongrass essential oil / Microorganisms / Microscopy / Nanoparticles / Oils & fats / Packaging / Packaging materials / Permeability / Petroleum industry / Polymer films / Polymers / Salmonella / Scanning electron microscopy / Shelf life / Silver / silver nanoparticles / Sodium / Softness / Spoilage / Storage conditions / Surface layers / Thermal analysis / Water vapor