Posted by: Bystander PJ27 JUN 2012
Do you use a plastic chopping board in your kitchen in the belief that it is more hygienic than a wooden board? Well, think again.
Some 20 years ago, the US Department of Agriculture realised that it had no scientific evidence to support its recommendation that home kitchens should use plastic cutting surfaces, so it asked researchers at a food safety laboratory to compare plastic and hardwood chopping boards.
The researchers applied a range of disease bacteria (including Escherichia coli O157:H7, Salmonella spp, Campylobacter jejuni, Listeria monocytogenes and Staphylococcus aureus) to various work surfaces. To their surprise, they found that soon after application they could no longer recover bacteria from wooden boards — even old ones with many knife cuts. But plastic surfaces allowed the bacteria to persist. And although new plastic boards were easily cleaned, older knife-scarred surfaces were impossible to disinfect manually.
It seems that bacteria are absorbed into wooden surfaces. They may remain alive within the wood for some time, but they do not multiply and they gradually die. They can only be detected by gouging the wood with a sharp blade. But the researchers also found that gouging a used plastic surface after manual cleaning recovers more bacteria than gouging a wooden board.
Plastic boards are usually dishwasher safe, but dishwashers do not reach a temperature that kills all bacteria. Wooden boards, if small enough, can be rapidly disinfected in a microwave; plastic ones cannot.
So it seems that wooden boards win hands down. Apart from the hygiene considerations, they are more aesthetically pleasing than plastic and do not dull your knife blades as quickly.
What about glass and metal boards? They are certainly more easily cleaned and disinfected than either wood or plastic, but both will rapidly blunt your favourite kitchen knife.