What’s lurking on the beverage lemon?

By Staff
Emily Campbell, Regional Extension Agent
An interesting news item is currently circulating on the internet and in the media, reporting a study of microbial growth on sliced lemons served on the rim of beverages in restaurants. Published in the Journal of Environmental Health in December, the research was conducted by Anne LaGrange Loving, Assistant Professor of Science at Passaic Community College in Paterson, NJ.
The results of the study indicate that a wide variety of microorganisms may survive on the flesh and/or rind of a sliced lemon and also that restaurant patrons should be aware that lemon slices added to beverages may include potentially pathogenic microbes.
In the study, samples were collected without the knowledge of the restaurant staff as soon as the beverage was served, before a sip was taken and before the lemon slice was touched by the patron. A total of 25 different microorganisms were recovered, including bacteria and yeasts. All have the potential to cause infectious diseases, although the likelihood was not determined in this study. An irony is that antimicrobial properties of lemons are well documented.
An extensive search of scientific literature yielded no reported outbreaks or illnesses attributed to lemon slices in beverages.
I write about this study for three reasons. First, as stated earlier, restaurant patrons should be aware that sliced lemons in beverages or as plate garnishes could contain potentially hazardous microbes. Often patrons are offered lemon with a beverage or order it on their own; at times the restaurant simply places the slice on the rim of the glass.
Secondly, while it is not possible to definitively establish the source of the contamination, certain of the bacteria found could have come from the hands of a restaurant employee through human fecal (restroom) contamination or from raw meat, fish or poultry cross contamination.
This study should alert restaurant managers and employees of the need for strict personal hygiene, most importantly proper and frequent hand washing. The Alabama Department of Public Health regularly inspects and scores every food service establishment. Scores are posted in a prominent place for patrons to see and everyone should check a restaurant’s latest score before taking a table.
The Health Department also has mandated that beginning Jan. 1, 2010, at least the managers of food service operations must pass an accredited food safety course and exam. Many many restaurants are postponing this investment until the deadline. Patrons should also check for the posted accreditation at the front of the restaurant, alongside the inspection score.
Thirdly, this study emphasizes what is almost always true about scientific research. It prompts as many questions as it provides answers. The researchers concluded that “further investigations could determine the source of the microorganisms, establish actual threat (if any) posed by their presence on the rim of a beverage and develop possible means for preventing the contamination of the lemons. It could also be worth while to study contamination on other beverage garnishes such as olives, limes, celery, and cherries…”. Microbes are everywhere. Do we need to worry about this source?
My advice would be to practice good personal hygiene whether you work in a restaurant or simply eat there, try to eat healthy to keep your immune system strong and to store the information from this study as food for thought while you wait for follow-up research to be reported.
More information about food safety and the Servsafe(r) Manager Certification program can be obtained by contacting Emily Campbell, Regional Extension Agent for Food Safety, Preparation and Preservation. campber@auburn.edu or (256) 574-2143.