Comparative effects of colloidal silver nanoparticles used in packaging film and spray in inactivating bacteria experimentally added to chicken eggshells

ABSTRACT

This study focused on the inactivation of bacterial growth using a mixture containing Salmonella enteritidis, Staphylococcus aureus, Bacillus cereus, and Escherichia coli. This bacterial mixture was added to chicken eggshells and subsequently targeted for elimination using two types of silver nanoparticle (Ag-NP) delivery systems: a composite film (named cover) and a colloidal spray. Both systems were applied to the eggshells’ packaging at concentrations of 500, 1000, and 2000 ppm over 28 days. A General Linear Model (GLM), repeated measurement-Analysis of Variance (ANOVA) procedure was used to analyse the effect of time and concentration of the Ag-NP materials on the inactivation of bacteria. The maximum reduction of bacterial growth resulted from the “Spray 2000 ppm”, for which the value of the bacteria reached a minimum (0.93 ± 0.42) on day 7, and was calculated to be undetected on days 14 and 28, followed by Spray 1000 ppm. In other words, increasing the concentration of the Ag-NP in both coatings, either spray or cover, significantly decreased the number of bacteria colonies on the eggshells. However, the effect of packaging with different concentrations of nanocomposites and the length of the study (number of days) did not show statistically significant results.

KEYWORDS:

• Bacteria
• Colloidal spray
• Composite film
• Eggshell
• Nanoparticle

Acknowledgments

We would like to thank both the head and the experts of the Razi Complex Laboratory of Science and Research Branch of the Islamic Azad University of Tehran, Iran, for their lab assistance and help with an earlier draft of our study.