Researchers develop new methods to identify potential sources of food contamination

Unwanted bacteria, yeasts and moulds can cause major problems for the food industry as well as consumers. Norwegian researchers have developed new methods to identify potential sources of contamination.

Microorganisms such as bacteria, yeasts and moulds can cause food spoilage and deterioration during food production. They could be lurking in the tubes that convey milk to cartons, lying in wait on the floor, or even floating in the air where sausages are being packaged. And they are poised to attack and contaminate our food at any time.

The food production chain is growing more and more complex - which increases the risk of food going bad at some point during production.

New methods

Troubleshooting during production is the food industry's current approach, using observation and testing to locate the causes of food spoilage.

Now the participants at a research project carried out by the research institute Nofima Mat and packaging company Elopak have developed a more effective method of identifying infection sources that is faster and more economical to use.

Tracing microbes

Using a spectrometer, the researchers are able to detect undesirable microorganisms in finished products and trace them back to the various steps in the production process.

Scientists have long used Fourier Transform Infrared (FTIR) spectroscopy as a method of chemical analysis, and for the last two decades for identifying bacteria as well. The method can also detect all types of microorganisms in air, fluids and many other substances.

"But no one had so far used the method for identifying food contaminants," says Henri-Pierre Suso, a researcher at Elopak.

He headed a user-driven project that received funding under the Research Council's Food Programme: Norwegian Food from Sea and Land.

Fingerprinting the culprits

Researchers at Nofima Mat have taken spectral readings of various microbes collected from a wide variety of foods, including juice and milk. Each microbe has its own unique spectral profile, which functions much like a fingerprint and was used for identification purposes.

"In the project we developed a database of information about the samples, where we have stored approximately 20 000 spectral profiles of different microbes. We've also implemented sound laboratory routines to ensure the readings are reproducible," explains Mr Suso. "Whenever we  found an unknown microbe, we took a spectral reading of it, then we compared its profile with those already entered in the database."

Low-cost solution

Mr Suso says there are currently a number of methods used for locating sources of contamination in the food industry, "but we are convinced that ours is the most cost-effective solution. It is a very precise and high-capacity method, with the additional advantage that technicians don't need to be specialists in mycology in order to identify the microorganisms."