Alginate Films Embedding Electrosynthesized ZnO Nanostructures for Food Packaging Applications

Even today, many products intended for food, though well cultivated, unfortunately undergo deterioration due to contamination by pathogenic microorganisms causing a considerable economic burden. Hence, new solutions are explored to improve food preservation. Biodegradable coatings with antimicrobial properties can prolong product shelf-life thus limiting pathogen growth and/or biofilm formation. In this work we propose cross-linked films based on alginate, a biodegradable polysaccharide biopolymer, modified with zinc oxide nanostructures (ZnO NSs). The nanomaterial was prepared through a green electrochemical-thermal method, using a sacrificial zinc anode corroded in a slightly alkaline bath in the presence of sodium dodecyl sulfate, as a stabilizer. A suitable protocol for fabricating self-supported ZnO NSs/alginate films was developed. Morphological and spectroscopic characterizations were performed on NSs to evaluate their composition and morphology. Films were characterized in terms of composition and water uptake, showing that the addition of ZnO NSs improves significantly their resistance, and supporting their potential application in food packaging studies.