Mahboubeh Mirhosseini; Fatemeh Barzegari Firouzabadi
Abstract
Background & Objectives: Direct addition of antimicrobial materials to food during food processing is an effective method for controlling microbial contaminants of food and extending the shelf-life of food products. Objective of this research was to study the antimicrobial effect of zinc oxide (ZnO) ...
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Background & Objectives: Direct addition of antimicrobial materials to food during food processing is an effective method for controlling microbial contaminants of food and extending the shelf-life of food products. Objective of this research was to study the antimicrobial effect of zinc oxide (ZnO) nanoparticle and potential applications of ZnO nanoparticles in terms of controling two food-borne pathogens in milk. Methods: Toxicity of different concentration (0, 0.5, 2, 5, and 10 mM) of ZnO nanoparticles on Listeria monocytogenesand Bacillus cereuswas studied in culture media and milk. Results: Among the mentiond concentrations, treatment of 10 mM of ZnO nanoparticle was the most effective one for L. monocytogenesand B. cereus inhibition, which completely inhibited the growth ofL. monocytogenesand B. cereusin 24h. These data revealed concentration-dependency of the antibacterial activity of ZnO. Therefore, 5 mM and 10 mM ZnO were selected for further studies, which were performed in milk, since they demonstrated significant growth inhibition. ZnO NPs were more capable in terms of reducing the initial growth counts of all the above-stated strains in milk. Conclusion: ZnO nanoparticles had an antimicrobial activity against L. monocytogenes and B. cereusin milk and the media. This work was a preliminary study that provided a starting point for determining whether the use of ZnO nanoparticles had the potential for being applied in food preservation or not.
Mahboubeh Mirhosseini; Fatemeh Barzegari Firouzabadi
Volume 9, Issue 2 , April 2014, , Pages 99-106
Abstract
Background & Objectives: Nanotechnology is one of great important part of technology. Nanoparticles can be used in different applications for industrial, medical, military and personal use. The objectives of this study were preparation of Polystyrene/ZnO nanocomposite films via a simple method and ...
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Background & Objectives: Nanotechnology is one of great important part of technology. Nanoparticles can be used in different applications for industrial, medical, military and personal use. The objectives of this study were preparation of Polystyrene/ZnO nanocomposite films via a simple method and investigation of antibacterial activity of them.
Methods: Polystyrene /ZnO nanoparticle (PS/nano-ZnO) composite films were prepared via simple method with 0, 0.1, 1 and 2.5% wt concentration of ZnO and characterized by scanning electron microscopy (SEM). The antibacterial properties of the product were investigated against Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Bacillus cereus.
Results: The survival ratio of L. monocytogenes, E. coli, S. aureus and B. cereus decreased with increase of ZnO content on PS/nano-ZnO composite films and the best antibacterial activity was obtained with 2.5% wt ZnO-PS composite films for all bacteria. Results show the larger sensitivity of the S. aureus compared to other bacteria.
Conclusion: The treated fabric with ZnO NP indicates significant improve for antibacterial properties for polystyrene fabric.
