Physical-mechanical and functional properties of chitosan-based films incorporated with silver nanoparticles

Abstract

Developing biodegradable, compatible, and non-toxic films based on chitosan that allows the incorporation of nanocomposites can be favorable for its application in various industries such as food industry. The objective was to develop films based on a chitosan biopolymer matrix added with silver nanoparticles (AgNPs) and evaluate their physical-mechanical, physicochemical, and microbiological properties for food packaging applications. AgNPs (by the Lee-Meisel method), and chitosan 1% (Q) solutions were synthesized, to evaluate the antimicrobial activity. Films of Q and Q-AgNPs were developed by the casting method and were evaluated by field emission scanning electron microscopy, color assessment, resistance to tension, elongation, elasticity, humidity, solubility, degree of swelling, permeability to water vapor, speed of transmission of water vapor and thickness. The combination of Q-AgNPs showed bacteriostatic effect, while AgNPs showed a delay in the onset of the logarithmic growth phase and decreased growth, compared to control. The Q and Q-AgNPs films were observed homogeneous without porosity. The color of the Q-AgNPs films was slightly more yellow and less luminous, which could confer protection from light. In the same sense, they were less permeable to water vapor which can give them a barrier function, offering a better protective effect for food, in addition, they were 9% more resistant to elongation, which makes them more malleable, under these conditions, it is concluded that Q-AgNPs films are feasible to be applied as coatings or packaging for food.