A newly published study by Irish researchers from the University of Limerick and the Moorepark Research Centre has found that slicing carrots with a blunt blade enhances the penetration of E. coli O157:H7 cells into tissue and their subsequent survival during storage at 8oC.
The researchers compared the effects of slicing with a blunt machine blade and with a razor blade. They found that significantly higher numbers of cells penetrated deeper (up to 1cm) into the carrot tissue when the blunt blade was used. In addition, the number of E. coli cells remained higher at all depths in carrot tissue sliced with the blunt blade for up to five days.
The study also found that different peeling methods had little effect on penetration and survival of the pathogen, but raising the temperature from 4 oC to 10 oC resulted in the growth of E. coli O157:H7 at all sample depths. The researchers suggest that the microbial safety of fresh cut produce can be improved by cutting with sharp blades.
The study is published in the journal Food Control and an abstract can be found here.