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Cutting Boards: Is That Surface Really Clean?. Background Information. Escherichia coli ( E.coli ) Escherichia coli is a common bacterium found in the human and animal intestinal tract.
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Background Information Escherichia coli(E.coli) • Escherichia coli is a common bacterium found in the human and animal intestinal tract. • It aids digestion, fights possible infection in the intestinal tract, and produces small amounts of vitamins B12 and K • E coli food poisoning occurs when, usually raw meat, or contaminated subjects are taken in by a person. • The result are abdominal pain, diarrhea, vomiting and fever. Tests on bamboo cutting boards • Cook’s Illustrated magazine found that in an independent lab test, bamboo cutting boards did have some natural bacteria-killing properties when compared to composite, wood and plastic boards. • Greenearthbamboo.com claims that bamboo is antimicrobial and that it is disliked by pests and pathogens; therefore making it antibacterial.
Question Do bamboo and wood cutting boards prevent the growth of bacteria when exposed to raw chicken drippings?
Hypothesis If fewer bacteria are found on the bamboo and wood cutting boards when compared to plastic boards, then bamboo and wood prevent bacterial growth
Procedure • Clean all surface areas. • Wash all bamboo, plastic and wood cutting boards with a 10% bleach solution(100mL bleach; 900mL water). • Once boards are dry, take sterilized swab, dip it in the Easy Gel Coliscan agar and remove. • Swab an area 15cm long and 3cm wide back and forth three times on each board. • Swirl in coliscan bottle and pour into Petri dish. • Take raw chicken drippings and evenly spread it over boards. • Let sit to dry for 15 minutes and then repeat the swab technique. • Wash boards with tap water and dry. Again, take three samples from each board using the sterile swabs, coliscans, and Petri dishes. • Wash boards with 5g of PalmOlive dish soap and 1L of tap water. • Allow to dry and take samples again by using a sterile swab, caliscan and Petri dish. • Clean all boards again in 10% bleach solution(100mL bleach; 900mL water) and dispose of used materials. • Place Petri dishes in incubator for three days at a temperature of 37⁰C. • Remove and count the bacteria colonies. Record results.
Independent Variable: type of cutting board used. • Dependant Variable: How much extracted bacteria is grown from the surface of the cutting board. • Constants: The even spreading of chicken drippings, sterile swabs, Easy Gel coliscans, Petri dishes, and temperature at which the dishes were held in incubator. • Control: Plastic cutting board
Variables • Only one packet of chicken was tested. • All three boards were new. • When contaminated, they were exposed to open air.
Conclusion • The wood and plastic cutting boards exhibited more bacterial growththan the bamboo, however the wood board contained far fewer colonies than the plastic. • The results of this experiment suggest that wood and bamboo could possibly have antibacterial qualities. • Used cutting boards should be tested in the same way • Water alone was enough to rid the cutting boards of most bacteria. Soap and water combined eliminated the bacteria completely, suggesting that simple cleaning was an effective way to dispel any bacteria. • The hypothesis was partially supported – both wood and bamboo exhibited fewer bacteria than plastic, however wood boards did show some growth.
Bibliography • "E. Coli Food Poisoning." Infoplease. Family Education Network, 2005. Web. 9 Feb. 2011.<http://www.infoplease.com/ce6/sci/A0858027.html>. • "Escherichia Coli." Infoplease. Family Education Network, 2005. Web. 9 Feb. 2011. <http://www.infoplease.com/ce6/sci/A0817668.html>. • "Cutting Boards Reviews and Research." Consumer Search. New York Times Co, 1 Jan. 2008. Web. 9 Feb. 2011. <http://www.consumersearch.com/ cutting-boards/reviews>.