Abstract
The aim of this study was to examine the influence of accelerated UV-aging on the activity against chosen microorganisms and the mechanical properties of poly-lactic acid (PLA) films enhanced with ZnO nanoparticles. The pure PLA films and tri-layered PLAZnO1%/PLA/PLAZnO1% films of 150 µm thickness were extruded. The samples were treated with UV-A and Q-SUN irradiation. After irradiation the antimicrobial activity and mechanical properties of the films were analyzed. The results of the study demonstrated that PLA films did not inhibit the growth of Staphylococcus aureus, Bacillus cereus, Escherichia coli, Bacillus atrophaeus, and Candida albicans cells. PLA films with incorporated zinc oxide nanoparticles decreased the number of analyzed microorganisms. Accelerated UV aging had no negative effect on the activity of the film containing nano-ZnO against Gram-positive bacteria, but it influenced the activity against Gram-negative cells and C. albicans. Q-SUN irradiation decreased the antimicrobial effect of films with incorporated nanoparticles against B. cereus. UV-A and Q-UV irradiation did not influence the mechanical properties of PLA films containing incorporated ZnO nanoparticles.
Highlights
The main function of food packaging is to maintain the quality and safety of food products during storage and transportation and to extend the shelf-life of the packed products by preventing unfavorable factors or conditions, such as microorganisms which cause spoilage, chemical contaminants, oxygen, moisture, or UV light [1]
The poly-lactic acid (PLA) films with incorporated ZnO nanoparticles reduced the number of viable S. aureus cells, but only to a very small degree (Figure 1)
ZnO nanoparticles incorporated into the PLA matrix were considered bacteriostatic due to their ability to reduce the growth of S. aureus cells
Summary
The main function of food packaging is to maintain the quality and safety of food products during storage and transportation and to extend the shelf-life of the packed products by preventing unfavorable factors or conditions, such as microorganisms which cause spoilage, chemical contaminants, oxygen, moisture, or UV light [1]. It has been shown that Shigella flexneri causes 1.5 million deaths annually, due to contaminated food and drinks, as reported by Kotloff, K.L. et al [2]. The number of Shigellosis was found to be 164.7 million, of which 163.2 million were in developing countries (with 1.1 million deaths) and 1.5 million in industrialized countries. A total of 69% of all episodes, and 61% of all deaths, attributable to shigellosis involved children under five years of age. The median percentages of isolates of S. flexneri, Shigella sonnei, Shigella boydii, and Shigella dysenteriae were 60%, 15%, 6%, and 6%
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
