1 / 16

What’s On My Water?

What’s On My Water?. Bacteria on Restaurant Lemon Wedges. Problem. Are restaurant lemon wedges free from bacteria? If not what is it that humans are ingesting ?. Background Information.

trisha
Download Presentation

What’s On My Water?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. What’s On My Water? Bacteria on Restaurant Lemon Wedges

  2. Problem • Are restaurant lemon wedges free from bacteria? If not what is it that humans are ingesting?

  3. Background Information • In 2008 Anne LaGrange Loving conducted an experiment with lemon wedges at restaurants to determine what exactly is on them • 53 out of 76 lemons that she swabbed were infested with bacteria • Lemon pulp is acidic; it registers with a pH of 4. This could possibly kill bacteria • Coliform bacteria is found in warm-blooded animals • Pathogenic bacteria tags along closely to coliform bacteria • Coliscan Easy Gel plates shows coliform bacteria as either blue or pink colonies

  4. Hypothesis • If lemon wedges from restaurants are tested for bacteria and coliformsand are compared to clean lemons, the restaurant lemons will have bacteria present.

  5. Materials • 15 lemon wedges: 10 from 2 restaurants ; 5 from a control lemon • 30 Coliscan Easy Gel plates • 30 cotton tipped sterile swabs • Bunsen burner • Gloves, lab coat, protective glasses

  6. Procedure • Lemons were collected from 2 restaurants • Lemons were swabbed using aseptic technique • Swabs were inserted and swirled in the liquid form of Coliscan Easy Gel • Set dishes were placed in the incubator for 96 hours at 37⁰ Celsius • Colonies were counted by using a grid. 8 sample blocks were counted, and the sum was multiplied by 4 • All dishes were disposed by autoclave

  7. Variables • Control: clean washed lemon • Independent: the restaurants • Dependant: the count of bacteria per wedge • Constants: temperature of incubator, amount of time in incubator, area of swabbing

  8. T-test between Restaurants and Control Lemon

  9. Conclusion • “If lemon wedges from restaurants are tested for bacteria and coliforms and are compared to clean lemons, the restaurant lemons will have bacteria present.”- was supported • No coliforms were found, so half of the hypothesis was rejected.

  10. Sources of Error • The incubator may have been opened for long periods of time thus causing a temperature change • Some condensation was found on the plates • In only one plate, spores of mold were found; this plate was discounted

  11. Further Research • A more comprehensive survey of restaurants • What exactly is on lemon wedges? • What type of soap kills the most bacteria?

  12. Works Cited • Growth. (1999). Introduction to Bacteria [Fact Sheet]. Retrieved from University of Missouri- Saint Louis website: http://www.umsl.edu/‌~microbes/‌introductiontobacteria.pdf • Instructions. (n.d.). Retrieved November 12, 2010, from Micrology Laboratories website: http://micrologylabs.mennonite.net/‌Home/‌Our_Methods/‌Coliscan_Media/‌Coliscan_Easygel/‌Instructions • Loving, A. L., & Perz, J. (2007, December 1). Microbial flora on restaurant beverage lemon slices. Journal of Enviromental Health. Retrieved from http://www.thefreelibrary.com/‌Microbial+flora+on+restaurant+beverage+lemon+slices-a0172839589 • Morton, J. F. (n.d.). Lemon. Retrieved October 6, 2010, from Perdue University website: http://www.hort.purdue.edu/‌newcrop/‌morton/‌lemon.html • pH Panel. (n.d.). The pH Factor. Retrieved October 21, 2010, from Miami Science Museum database.

  13. Works Cited Continued • Reynolds, G. (2007, March 21). Bacteria effective against fresh cut fruit contamination. Food Production Daily. Retrieved from http://www.foodproductiondaily.com/‌Quality-Safety/‌Bacteria-effective-against-fresh-cut-fruit-contamination • Stone, A. H. (1966). Chemistry of a Lemon. Englewood Cliffs, New Jersey: Prentice Hall. • Wassenaar, T., Dr. (2009, January 6). Food Safety [Virtual Museum]. Retrieved October 7, 2010, from http://bacteriamuseum.org/‌cms/‌Food-And-Water-Safety/‌food-safety.html

More Related