The team from Nofima Mat and Elopak said it is the first to develop a process using a Fourier Transform Infrared (FTIR) spectroscopy that tests and “fingerprints” product samples as they travel through the various stages of production process from raw material to the packaging line and beyond.
The second step in fingerprinting technique – which involves building up a unique spectral image of microorganisms – examines the finished products. If it finds a microorganism it compares the profile with ones stored in a database to identify exactly where in the supply chain the bacteria, mould or yeast first appeared in the product.
Project leader Henri-Pierre Suso, of Elopak, told FoodProductionDaily.com: “In order to find the source of contamination a high number of samples are taken along the production chain - such as raw material, after processing, after packing, after distributing.”
Using the group’s technique, the FTIR instrument is able to gather 100 fingerprints per hour- meaning the number of samples taken in the field can the field can be quite high, he added
“After collecting all fingerprints, we need to fingerprint the spoilt sample(s) found to look for a fingerprint match,” said the researcher. “Then our software will look for fingerprint match. By doing that we are able to find the source of the food spoilage - be it in the raw material or during processing.”
Database
Fundamental to the system’s efficacy is the database and scientists from Nofima Mat have compiled spectral readings of various microbes collected from a wide variety of foods, including juice and milk.
“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,” said Suso.
Expansion of the database is an on-going task and companies that are interested in the process will be able to develop their own.
Low-cost solution
Another advantage of the process is its low cost, with the main expense being the FTIR instrument, said Suso.
He added: “Consumable are very limited and are very cheap and we think we are able to reduce the cost by 50 per cent compared with DNA technique such as polymerase chain reaction (PCR).”
While acknowledging that several other methods exist to pinpoint contamination sources, Suso said the team was convinced theirs was “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,” he said