Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SATURDAY, February 13, 1993 TAG: 9302130182
SECTION: EXTRA PAGE: 4 EDITION: METRO
SOURCE: KAROLA SAEKEL SAN FRANCISCO CHRONICLE
DATELINE: LENGTH: Medium
IS YOUR CUTTING BOARD SAFE?
Since the recent rash of food poisonings in the Pacific Northwest, public concern over food contamination through improper handling has increased.Washington state health officials believe that the deaths of two children and the severe diarrhea affecting at least 250 people were caused by contamination of beef in the slaughterhouse.
Now a professor has exploded a little bombshell by, in effect, telling consumers that they may be contaminating food in their own kitchens by following what they think are safe practices - using plastic boards when cutting up meat and poultry.
Research conducted by Dean O. Cliver at the University of Wisconsin-Madison Food Research Institute showed far more bacteria surviving on plastic than on old-fashioned wooden cutting boards.
"It's become an article of faith among `experts' that plastic cutting boards are safer than wood for food preparation because . . . plastic is less hospitable to bacteria," a university news release states. It goes on to report that Cliver and microbiologist Nese O. Ak found that in a manner not fully understood, bacteria disappear quickly from the surface of wooden cutting boards.
In a telephone interview, Cliver set out this scenario: "I am cutting up a chicken on my cutting board. After the bird is in the oven, I am going to prepare salad ingredients. I am not going to put that board in the dishwasher and wait 45 minutes."
So the board gets a rinse or a wipe and is used for the next chore - dangerous if the board is plastic, OK if it's wood.
Plastic boards scarred by knife marks are particularly hospitable to bacteria, Cliver says, possibly not even becoming fully decontaminated in a dishwasher.
Other food scientists who had not yet seen Cliver's research expressed surprise at the findings.
Barry G. Swanson of Washington State University believes that bacteria-carrying food would set up "a nice culture" on wood. Christine Bruhn of University of California at Davis said she had subscribed to the theory that a plastic board run through a dishwasher was safe, whereas a wooden board would need to be cleaned with bleach.
Cliver reports using E. coli, the bacteria implicated in the outbreak in the Northwest, in much of his research and testing seven kinds of wood - hard maple, black cherry, basswood, American black walnut, birch, butternut and beech. Results were the same on all woods, just as they didn't vary between different kinds of plastic: Three minutes after contamination occurred, wooden boards were 99.9 percent safe, the bacteria on plastic were alive and well.
The research continues in the hope of finding what happens to the bacteria.
"We know they don't die that fast," Cliver explains, "but they are not on the surface where they can contaminate other foods."
Apparently, as fluids from meat or poultry are absorbed by the wood, so are the bacteria. On plastic, no such thing occurs.
Cliver's research leads him to believe that wood, cleaned with detergent and water, is probably the safest surface to use in the kitchen.