Safe Ulvan Silver Nanoparticles Composite Films for Active Food Packaging

Abstract

Protecting food from the corruption caused by different microbes is a big problem, as we need safe methods for food packaging. In this study, Ulvan (U), edible sulfated polysaccharide extracted from Ulva lactuca, was mediated for the first time non-toxic biosynthesized silver nanoparticles (Ag-NPs) to produce new and safe bio-nanocomposite films called (U/Ag-NPs) films for active food packaging. Ulvan was extracted by hot water-extraction and ethanol-precipitation method and was characterized by FT-IR spectroscopy. Biosynthesis of silver nanoparticles using U. lactuca was proven by Ultra Violet-Visible (UV-VIS), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) analyses. Investigation of films was by incorporation 1m M of Ag-NPs into different concentrations of ulvan (3, 6 and 12%, w/v). The formation of bio-nanocomposite films was confirmed by FTIR-ATR spectroscopy and TEM analysis. Bio-nanocomposite films were further characterized by physical parameters as water vapor permeability (1.18±0.07, 0.9±0.09 and 0.55±0.1 10⁻⁸ g mm cm⁻² h⁻¹ Pa⁻¹), film thickness (0.01, 0.03 and 0.08 mm) and contact angle measurements (70.833°, 81.066° and 109.066°) respectively. The bio-nanocomposite films also showed high antimicrobial activity using Kirby-Bauer method as antibacterial and good antioxidant activity with IC₅₀ = 1.128 µg/ml. (U/Ag-NPs) bio-nanocomposite films exhibited good chemical and physical properties, antioxidant and antimicrobial activities making them a potential substitute for active food packaging to extend shelf-life of foods during processing, transportation and storage with no harm as previous packaging methods.