Microbial Activity in Soda Fountain Machines

In this study, microbial activity in Soda Fountain Machines (SFMs) was monitored twice over the course of 13 months, in Roanoke, Virginia. Researchers were interested in comparing the growth patterns in the plastic tubing and nozzles, that lead to detectable amounts of beverage microbial contamination. The different beverages, from different SFMs showed results sometimes higher than 500 CFU/mL for heterotrophic plate count (HPC). They found no correlation between disinfecting regimens and the amount of HPC. Another finding, was that HPC was highest right after disinfecting plastic tubing of SFMs rather than before or 11 days later. They concluded that the disinfectants did not completely remove the microbes from the tubing, but briefly provoked a growth in biofilm density. They also found that SFMs that were frequently used, resulted in less microbial contamination of beverages. Thus, encouraging the dispensing of beverages from SFMs before serving yourself.  This study is important because it makes us more aware of the abundance of microbes, and possible microbial contamination found in our beverages.

 

Graph showing  and describing one of the findings, taken from Goddard and colleagues (2013).

References:

Godard, R., Sharma, P., Wagner, C., Wilson, C., Fleming-Haddock, A., & Beach, R. (2013). Repeated detection of microbes in beverages dispensed from soda fountain machines and the effect of flushing on microbial density. International Journal of Food Microbiology, 163(2-3), 218-222. doi:10.1016/j.ijfoodmicro.2013.03.007