Nanopartículas de prata: método alternativo de sanitização para couve minimamente processada1

Abstract

INTRODUÇÃOO mercado de alimentos minimamente processados é cada vez mais popular, por assemelharem-se a produtos frescos e que possuem maior padronização, conveniência e praticidade. No Brasil, diversos são os produtos potencialmente utilizáveis como minimamente processados, destacando-se a alface, brócolis, cenoura, repolho e couve. Essa última é altamente ABSTRACT RESUMOconsumida pela população brasileira, o que viabiliza o seu uso como alimento minimamente processado (Heimler et al. 2007 Silver nanoparticles: an alternative method for sanitization of minimally processed cabbageThe 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. KEY-WORDS:Brassica oleracea L.; antimicrobial agents; hydrophobicity.

Stainless steel and polyethylene surfaces functionalized with silver nanoparticles

“…For the SS surfaces and PE coated and control surfaces, the contact angle between the surface and water, formamide and α-bromonaphthalene was determined using a goniometer (Kruss, Germany). The contact angle of a 2.0 µl drop was measured every second for a period of 30 s for all liquids and evaluated surfaces (Araujo et al., 2015; Cieśliński and Krygier, 2014). The measurements were performed at 25 ℃.…”