Silver nanoparticles: an alternative method for sanitization of minimally processed cabbage

Abstract

The minimal processing of vegetables basically aims to extend food shelf life, which depends on a number of factors, such as sanitization, that is considered a critical step for food microbiological quality. However, the usual antimicrobial agents reduce the microbial population in a maximum of two logarithmic cycles. Therefore, it is necessary to develop alternative sanitizers. This study aimed to increase the innocuity of minimally processed cabbage through sanitization with silver nanoparticles. It was observed that the nanoparticles promoted three logarithmic reductions, i.e. a 99.9 % reduction rate, in the Escherichia coli population inoculated on the cabbage surface. When compared to other antimicrobial agents (sodium dichloroisocyanurate and sodium hypochlorite), the nanoparticles were more efficient in sanitizing minimally processed cabbage, showing a lower count of aerobic mesophils. It was also observed that the cabbage surface presents hydrophobic characteristics, resulting in a higher propension for bacterial adhesion, which was confirmed in the thermodynamic evaluation of favorable adhesion for Staphylococcus aureus, Escherichia coli and Listeria innocua.