DECONTAMINATION OF PLASTIC AND WOODEN CUTTING BOARDS FOR KITCHEN USE

Decontamination of plastic and wooden cutting boards was studied, with a view to preventing cross-contamination of foods in home kitchens. N ew and used plastic (four polymers plus hard rubber) and wood (nine ha rdwoods) boards were cut into 5-cm square blocks (25 cm(2) area) for t hese experiments. Bacterial contaminants--Escherichia coli (two nonpat hogenic strains plus serotype 0157:H7), Listeria innocua, L. monocytog enes, or Salmonella typhimurium--applied to the block surface in nutri ent broth or chicken juice, were recovered by soaking the surface in n utrient broth or pressing the block onto nutrient agar, within minutes or greater than or equal to 12 h later. Persistence and overnight mul tiplication of bacteria on plastic surfaces depended on maintenance of humidity so as to prevent drying of the contaminant. New plastic cutt ing surfaces were relatively easy to clean and were microbiologically neutral, but plastic boards with extensive knife scars were difficult to clean manually, especially if they had deposits of chicken fat on t hem. Fewer bacteria were generally recovered from wooden blocks than f rom plastic blocks. Clean wood blocks rapidly absorbed all of the inoc ulum, after which the bacteria could not be recovered within 3 to 10 m in. If the board surface was coated with chicken fat, some bacteria mi ght be recovered even after 12 h at room temperature and high humidity . Cleaning with hot water and detergent generally removed these bacter ia, regardless of bacterial species, wood species, and whether the woo d was new or used.