Related Experiment Video

Updated: Sep 28, 2026

Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition
10:45

Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition

Published on: February 5, 2022

Magnetized carbonyl iron and insoluble zirconium hydroxide mixture facilitates bacterial concentration and separation

Mark A Cullison1, Lee-Ann Jaykus

  • 1Department of Food Science, College of Agriculture and Life Science, North Carolina State University, Raleigh 27695-7624, USA.

Journal of Food Protection
|November 15, 2002
PubMed

Insights

A novel magnetized carbonyl iron-zirconium hydroxide mixture effectively concentrates foodborne pathogens like Salmonella and Listeria from milk. This method offers rapid, inexpensive, and efficient bacterial concentration for food safety applications.

Area of Science:

  • Food Microbiology
  • Analytical Chemistry
  • Materials Science

Background:

  • Foodborne pathogens pose a significant public health risk.
  • Accurate and efficient detection of pathogens in food is crucial for safety.
  • Current concentration methods can be time-consuming or costly.

Purpose of the Study:

  • To investigate a novel magnetized carbonyl iron-zirconium hydroxide mixture for concentrating foodborne pathogens.
  • To evaluate the efficiency and viability of bacterial recovery using this method.
  • To assess the potential of this technique for routine food safety analysis.

Main Methods:

  • Artificially contaminating nonfat dry milk samples (25 ml) with Salmonella enterica, Listeria monocytogenes, and Bacillus cereus spores.
  • Employing a two-step concentration process: high-speed centrifugation followed by a magnetized iron-zirconium hydroxide mixture.
  • Assessing bacterial recovery rates through supernatant analysis and direct pellet plating.

Main Results:

  • Bacterial recovery rates exceeded 75% for all tested pathogens and inoculum levels, often surpassing 90%.
  • The magnetized mixture demonstrated minimal toxicity to Salmonella Enteritidis and Listeria monocytogenes.
  • The concentration scheme achieved a 25-fold sample volume reduction while maintaining bacterial viability.

Conclusions:

  • The magnetized carbonyl iron-zirconium hydroxide mixture is a promising tool for bacterial concentration in food systems.
  • This novel compound facilitates inexpensive, rapid, and effective pathogen concentration.
  • The method supports enhanced food safety by improving pathogen detection capabilities.

More Related Videos

Cell Labeling and Targeting with Superparamagnetic Iron Oxide Nanoparticles08:26

Cell Labeling and Targeting with Superparamagnetic Iron Oxide Nanoparticles

Published on: October 19, 2015

Fabrication of a Functionalized Magnetic Bacterial Nanocellulose with Iron Oxide Nanoparticles08:59

Fabrication of a Functionalized Magnetic Bacterial Nanocellulose with Iron Oxide Nanoparticles

Published on: May 26, 2016

Related Concept Videos

Centrifugation01:05

Centrifugation

Centrifugation is a separation technique based on differences in density or size. It is commonly used to separate solids from aqueous interferents. During centrifugation, the sample is placed in centrifugation tubes and spun at high angular velocity, which allows centrifugal force to act differentially on the different densities or masses of the components. After spinning, the supernatant liquid is decanted. Depending on the specific application, either the pellet or the supernatant is retained...
Overview Of Cell Separation And Isolation01:20

Overview Of Cell Separation And Isolation

Cell separation was first achieved in 1964 by S. H. Seal, who separated large tumor cells from the smaller blood cells using filtration. Two years later, Pohl and Hawk performed experiments on how cells respond differently to a nonuniform electric field based on the cell type. Such observations were the inception of cell separation methods, which allow isolating a single cell type from a heterogeneous sample.
Subcellular Fractionation01:32

Subcellular Fractionation

The homogenate obtained after cell lysis contains various membrane-bound organelles that can be further separated into pure fractions by subcellular fractionation. These isolates are used to study specific cellular components, analyze localized protein activity, and are even employed in diagnostics. Fractionation is typically achieved using centrifugation methods, the most common being density-gradient and differential centrifugation.
Differential Centrifugation
Differential centrifugation is...