140 research outputs found
Development and Evaluation of qPCR Detection Method and Zn-MgO/Alginate Active Packaging for Controlling Listeria monocytogenes Contamination in Cold-Smoked Salmon
To answer to food industry requests to monitor the presence of L. monocytogenes in
cold-smoked salmon samples and to extend their shelf-life, a qPCR protocol for the detection of
L. monocytogenes, and an antibacterial active packaging reinforced with zinc magnesium oxide
nanoparticles (Zn-MgO NPs) were developed. The qPCR allowed the sensitive and easy detection
of L. monocytogenes in naturally contaminated samples, with specificity in full agreement with the
standard methods. The halo diusion study indicated a high antibacterial eciency of 1 mg/mL
Zn-MgO NPs against L. monocytogenes, while the flow cytometry showed only moderate cytotoxicity
of the nanoparticles towards mammalian cells at a concentration above 1 mg/mL. Thus, the novel
active packaging was developed by using 1 mg/mL of Zn-MgO NPs to reinforce the alginate film.
Cold-smoked salmon samples inoculated with L. monocytogenes and air-packed with the Zn-MgO
NPs-alginate nanobiocomposite film showed no bacterial proliferation at 4 C during 4 days. In the
same condition, L. monocytogenes growth in control contaminated samples packed with alginate
film alone. Our results suggest that Zn-MgO nanoparticles can extend the shelf-life of cold-smoked salmon samples
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