Fancy a few sweets? Think again if you are buying them from a pick and mix stand. You may be buying more than your liquorice or jelly beans.
The scoops and bins may be alive with bacteria left behind by previous customers, according to a project at the BT Young Scientist and Technology Exhibition. And while the most hazardous bugs weren’t found, those on hand are enough to make you ill at the thought.
The project put Zoe and Orlaith Fox, both 15, and Shannan Feeley right off the idea of using pick and mix sweets. The three are transition year students at St Clare’s Comprehensive School, Manorhamilton, Co Leitrim, and their two part project involved a search for bacteria but also ideas of how to reduce the bacteriological risks, explained Shannan.
The main organisms found were staphylococcus and micrococcus bacteria and most of the bacteria were found on the scoops and on the bins, said Orlaith.
The sweets too were often contaminated, however, said Zoe. They tested a range of sweets and found that those with granular sugar coatings were usually clear of bacteria because the organisms can not tolerate the sugar.
The bad boys in the bins turned out to be liquorice all sorts, they discovered. Shannan put it down to customers who dig through the bin to get the particular sweets they want.
The students learned how to collect samples and then use petri dishes to grow bacterial cultures. The weather proved a bit of a problem when they couldn’t get in touch with microbiologists at Sligo Institute of Technology who were helping them identify the bacteria, but the three still got their project to the RDS in time for the exhibition.
They came up with two ways to keep bacterial counts low. One involves the use of a robot arm which the customer uses to fetch the sweets he wants. The other is a dispenser that can deliver sweets from a vertical bin. Until these kinds of facilities are installed the pick and mix market is unlikely to see Zoe, Orlaith or Shannan making a visit any time soon.