Novel silver-based nanoclay as an antimicrobial in polylactic acid food packaging coatings

Abstract

This paper presents a comprehensive performance study of polylactic acid (PLA) biocomposites, obtained by solvent casting, containing a novel silver-based antimicrobial layered silicate additive for use in active food packaging applications. The silver-based nanoclay showed strong antimicrobial activity against Gram-negative Salmonella spp. Despite the fact that no exfoliation of the silver-based nanoclay in PLA was observed, as suggested by transmission electron microscopy (TEM) and wide angle X-ray scattering (WAXS) experiments, the additive dispersed nicely throughout the PLA matrix to a nanoscale, yielding nanobiocomposites. The films were highly transparent with enhanced water barrier and strong biocidal properties. Silver migration from the films to a slightly acidified water medium, considered an aggressive food simulant, was measured by stripping voltammetry. Silver migration accelerated after 6 days of exposure. Nevertheless, the study suggests that migration levels of silver, within the specific migration levels referenced by the European Food Safety Agency (EFSA), exhibit antimicrobial activity, supporting the potential application of this biocidal additive in active food-packaging applications to improve food quality and safety.

Six open questions about the migration of engineered nano-objects from polymer-based food-contact materials: a review

“…The fraction of nanoparticulate Ag in relation to the total migrated Ag ranged from below 1% to 69% (Echegoyen & Nerín 2013;von Goetz et al 2013;Ramos et al 2016). Several studies on AgNP-containing polymers did not examine if the observed migration of Ag was due to migration of AgNPs (e.g., Busolo et al 2010;Emamifar et al 2010;Song et al 2011;Bott et al 2014b;Jokar & Abdul Rahman 2014). Only one experimental study that applied a method to detect ENOs (transmission electron microscopy -TEM) described the absence of AgNPs in migrates from AgNP-containing polymer (Ntim et al 2015).…”

Use of Nanotechnology in Food Industry: A review

“…Formulation of nanobiocomposites combining nanosilver with nano-clay or other nanomaterials (e.g. titanium dioxide) to enhance both barrier and antimicrobial properties has also been studied for potential future application in food packaging (Busolo et al 2010, Cozmuta et al 2014. Other examples of nanomaterials potentially used in food packaging6 include alumina (e.g.…”

Development of active, nanoparticle, antimicrobial technologies for muscle-based packaging applications

“…Among the thermoplastics assessed, PVC gave the highest percentage reduction of E. coli as the silver release from PVC was greater than that observed for MDPE, PS or PET. (Busolo, Fernandez, Ocio, & Lagaron, 2010) obtained solvent casted antimicrobial active polylactic acid biocomposite films containing a novel silver-based antimicrobial layered silicate additive. The developed films were highly transparent with enhanced water barrier and strong biocidal properties and showed potential in extending the shelf-life of food products, including meat.…”