Rest assured, our smoked salmon is safe!

Here’s an article condensed from the Journal of Food Science, which I am sure will greatly reassure my Vegan authority in this semester’s class. By the way, Vegan does not refer to someone from Vega, but means someone who does not include any animal derived products in their diet (the cookies were delicious, even despite not having any butter or eggs in them!!!!)

The gist of the article presents a new model on understanding temperature effects on microbial control, specifically by ensuring that our nation’s supply of smoked salmon remains safe to eat. Many food products can become contaminated with the Gram positive bacillus Listeria monocytogenes, an organism that doesn’t cause significant disease in immunocompetent individuals, but is a significant cause of stillbirths in the United States.  As Science Daily stated:

… researchers determined that every 9 degree F increase in temperature resulted in a 10-fold increase in rates of inactivation of Listeria. They used this and other data from the study to create the mathematical model.

We can all rest assured that our salmon at least will remain for weeks after opening the package! We may have to go out and buy some more bagels after the weekend.

In addition to the temperature effects noted here by the authors, what other factors are coming into play with retarding the growth of microorganisms in this situation? Note it in the comments below, and earn bonus points!


About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on October 28, 2010, in Bonus!, Microbes in the News, Strange but True and tagged , . Bookmark the permalink. 8 Comments.

  1. Concentrations of salt and smoke compounds are the other factors to retard the growth of microorganisms.

  2. Harrison Jacoby

    Salting and smoking are also used to combat the growth of microorganisms. Salt’s hypertonic property creates an uninhabitable environment for most microorganisms. Smoking is used to reduce the moisture content of the fish also making an uninhabitable environment for microorganisms.

  3. Kristen Trevino

    In order to retard growth, another factor to consider is salt content. By increasing the optimal salt level for Listeria monocytogenes, this could limit microbial growth. If there is a way to preserve the salmon by keeping it packaged in a solution with higher salt concentration than L. monocytogenes can grow in, growth could be inhibited while also increasing the shelf life of the salmon, allowing it to keep longer. Perhaps by doing this, pH could also be altered to non-optimal conditions, thus aiding in microbial growth inhibition.

  4. Kristen, being a previously approved commenter, was able to jump in with the correct answer without me needing to approve it. Sangwon and Harrison also had the correct answer as well, but were prior to the time that the answer was seen. The answers “smoke” and “salt” have now been taken.

    Does anyone have any other ideas? Note, they probably wouldn’t be effective against Listeria, but might be effective against other bacteria. Hint: check the Wikipedia link I stuck in the article.

  5. Another way to possibly inhibit bacterial growth would be by bacteriophages. Bacteriophages are viruses that infect a specific bacterium by attaching to the cell’s receptors for that virus. The bacteriophages could be sprayed on fresh fruit and meats to prevent microbial growth.

  6. Spraying one specific type bacteriophage product from EBI Food Safety to the foods. In other word, spraying certain bacteriophage product which is targeting specific microorganism of food contamination.

  7. Maybe try irradiating the salmon before packaging.

  8. What about the very strict anaerobic environment that will be the result of the packaging? Those salmon packets are vacuum sealed tightly, and have no oxygen to speak of at that point. Any organism in there would have to be a facultative anaerobe, and would grow slowly, or a strict anaerobe.

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