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 diffusion study indicated a high antibacterial efficiency 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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Applications of ZnO and MgO Nanoparticles in Reducing Zinc Pollution Level in Rubber Manufacturing Processes: A Review

Current Biochemical Engineering ◽

10.2174/2212711906666200224105931 ◽

2020 ◽

Vol 6 (2) ◽

pp. 103-107 ◽

Cited By ~ 1

Author(s):

Seyyed Mohammad Javadi

Keyword(s):

Zinc Oxide ◽

Fatty Acid ◽

Magnesium Oxide ◽

Environmental Effects ◽

Pollution Level ◽

Oxide Nanoparticles ◽

Mgo Nanoparticles ◽

Magnesium Oxide Nanoparticles ◽

Council Directive ◽

Zno Particles

Background: Rubber vulcanization is a consolidated chemical process to enhance the mechanical properties of the polymeric material by sulfur crosslinking of the polymer chains, such as rubber. Vulcanization Activators are important rubber processing additives that activate sulfur cure and improve the efficiency of sulfur-based cure systems. The most common activator is zinc fatty acid ester that is often formed in-situ by the reaction of fatty acid with zinc oxide. Although zinc is one of the less harmful heavy metals, according to European Council Directive 2004/73/EC, the reduction of zinc level in the environment has become an important task because of its toxic effect on aquatic organisms. : The current study reviews the research achievements in the field of reducing the consumption of micronutrients of ZnO particles based on the use of nanoparticles instead of them in the polymer industry. Among the proposed methods, due to the less environmental effects of magnesium oxide, the use of MgO nanoparticles instead of zinc oxide has also achieved good results. Objective: The aim of this paper is considering suggested different methods on the reduction of using ZnO particles in related industries, the use of ZnO nanoparticles has had better results than its particles. In addition, due to the less environmental effects of magnesium oxide, magnesium oxide nanoparticles can be used instead of micronutrients of zinc oxide. Overall, the results of various investigations show that reducing the diameter of the zinc oxide particles reduces the amount required for curing the rubber and thus reduces its toxic effects. Also, the use of magnesium oxide nanoparticles instead of zinc oxide in different concentrations is investigated.

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