Research

Pulsed UV Light for Inactivating Listeria on Cold-Smoked Salmon

Problem:

Listeria monocytogenes is a well-known ubiquitous pathogen that has caused many illnesses and death in a variety of foods due to under-processing, no thermal processing and post-processing recontamination. The U.S. Food and Drug Administration (FDA) has established a zero tolerance for this pathogen due to its lethality and prominence in food safety studies. This zero tolerance level has been an impediment to effective marketing of cold smoked Alaska salmon fillets.

Approach:

New UV technology, in the form of the SteriPulse-XL Sterilization Chamber (Model RS-3000C, Xenon Corp.) will be used to generate pulsed UV light for sterilization of cold smoked salmon fillets. Inoculated samples will be treated with UV, and after incubation at 35°C, colony-forming units per gram of cold-smoked salmon will be calculated. Treated and stored products at refrigeration temperatures will be monitored to determine if the Listeria species can recover from the pulsed UV treatment. This non-thermal process may be an application for the cold-smoked salmon industry to use for ensuring zero tolerance for L. monocytogenes. That this work is still ongoing has been caused by delays in getting appropriate electrical connections for the Xenon UV light system installed in the FITC Pilot Plant. These have recently been completed and experimentation can begin. When the results have been analyzed, the data will be published as a scientific paper.

Results:

None at this time.

Contact person:

Dr. Brian Himelbloom: bhhimelbloom@alaska.edu