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Re: GBlist: cutting boards again
One more excellent reason to join those evolving out of the carnivore stage.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
At 08:35 AM 5/1/97 -0700, you wrote:
>Somebody wrote that this has been discounted - anyone have anything
>current on the 'cutting board controversy'
>John Salmen
>TERRAIN E.D.S.
>terrain@seaside.net
>
>From Science News, February 6, 1993
>
>By J. Raloff
>Reprinted from the Central Coast Avicultural Society, April 1993
>Reprinted from the San Diego Bird Breeders Journal
>
>For several years We've been encouraged to use plastic or other
>nonporous materials as cutting boards by leading
>veterinarians. This article argues against that practice.
>
>Chefs know that, any way you slice it, wooden surfaces are kinder to
>knife blades than either plastic or glass. But in
>recent years, everyone from kitchen suppliers to the Dept. of
>Agriculture (USDA) has urged cooks to cut on non-porous
>materials, typically plastic. Supposedly, plastic boards give bacteria,
>such as Salmonella in chicken, less chance of
>escaping rigorous cleaning, thus reducing the chance that such bugs will
>survive to contaminate other foods.
>
>If such arguments have frightened you away from slicing, dicing, or
>boning on wood, you may be able to bring your
>butcher block out of retirement. New research indicates that the safety
>advocates were wrong: Pathogens prefer plastic.
>
>No one was more surprised by this than Dean O. Cliver and Nese O. Ak,
>two microbiologists at the University of
>Wisconsin-Madison. They began studying cutting boards in hopes of
>identifying decontamination techniques that might
>render wood as safe as plastic. But the pair quickly found that within
>three minutes of inoculating wooden boards with
>cultures of common food-poisoning agents -- up to 10,000 cells of
>Salmonella, Listeria, or Escherichia call - 99% of the
>bacteria were unrecoverable and presumed dead. Under similar conditions,
>none of the bugs on plastic died.
>
>Indeed, when the researchers maintained plastic boards overnight at high
>humidity and room temperature, microbe
>populations grew; the researchers recovered no live bacteria from wood
>the next morning.
>
>The scientific literature suggests that the number of Salmonella cells
>that might wash off a chicken carcass probably will
>not exceed about 1,000, Cliver notes. "We can get less than 99.9 percent
>kills [on the wooden boards in three minutes]
>if we go to inordinately high levels of inoculation -- such as 1 million
>or more bacterial cells," he says. In those instances,
>he and Ak had to wait about two hours before achieving a 99.9 percent
>reduction in the bugs they recovered.
>
>"While the wooden boards appear to kill bacteria, we've not recovered
>the little critters' dead bodies," Cliver
>acknowledges. "So all we know is that by the best available means, we
>can't get them back after they go onto a board.
>The big concern is whether bacteria hiding deep within the wood might
>subsequently surface to contaminate the foods on
>the chopping block. As best as we can tell, that isn't going to happen,
>" Cliver says.
>
>The same is not true of knife-scored plastic cutting boards. The
>scientists found that bacteria lodged in the plastic's cut
>grooves not only survived a hot water-and-soap wash, but could later
>surface to contaminate foods. By contrast, Cliver
>says, with wood "a good wipe will do fine - and if you forget to wipe
>the board, you probably won't be too bad off."
>
>At one point, the Wisconsin researchers Inoculated wood and plastic on
>three successive days, maintaining each board
>without cleaning - at room temperatures and high humidity. By that time,
>"the plastic boards were downright disgustingly"
>Cliver says, "while the wood boards had about 99.9 percent fewer
>bacteria than Ak had put on them."
>
>"Wood is more forgiving - and perhaps user-friendly - than plastic is
>once it's been cut some," Cliver says.
>
>Boards sold to homeowners typically come from the factory treated with
>mineral oil. "That treatment is intended to make
>the wood more impermeable - like plastic," Cliver says. The bad news is
>that It does make wood more like plastic....In
>every one of our tests, if the wood had been treated to retard the
>penetration of moisture, the bacteria survived longer."
>
>Wood's presumed bactericidal activity does not depend on whether it is
>new -- nor, apparently, on species. Cliver and
>Ak have already tested boards from hard maple, birch, black cherry,
>basswood, butternut and American black walnut.
>Tests on oak and ash are pending.
>
>The microbiologists hope to submit their findings for publication within
>the next few months. One weakness. Cliver notes,
>is their inability to nail down the mechanism or agent responsible for
>wood's antibacterial properties.
>
>Although no laws prohibit commercial establishments from using wooden
>cutting boards, the Food and Drug
>Administration's model codes for state agencies call for using only
>"Non-absorbent" and easily cleaned materials for
>surfaces that food contacts. The USDA also recommends acrylic or other
>nonporous materials to consumers asking
>about preferred cutting boards, according to Bessie Berry with its Meat
>and Poultry Hotline in Washington, D.C.
>
>Cooks should never cut on glass, she says because minute shards may chip
>off and become embedded in food.
>
>Microbiologist Pricilla Levine of USDA's Food Safety and Inspection
>Service says she knows of no scientific studies
>demonstrating the advantages of one cutting-board material over another
>in inhibiting bacterial contamination. She told
>Science News that her agency based its recommendations on "common
>sense."
>
>Like state and local inspectors, these federal agencies have bought the
>myths that plastic is safer than wood, says food
>scientist 0. Peter Snyder, a St. Paul, Minn. based consultant to the
>retail food industry. For at least two decades, he
>says, "sanitarians [Sanitation inspectors] out there have been telling
>us to use plastic cutting boards, even though they had
>no evidence that plastic was better."
>
>Indeed, Snyder contends, the little research done on the subject has
>failed to demonstrate plastic's superiority. He cited
>one study conducted about 25 years ago that showed wooden cutting boards
>were at least as good as plastic when it
>comes to cleaning off microbial contamination.
>
>If others confirm the Wisconsin data, Snyder says, sanitarians may have
>to alter their advocacy in favor of wood. But, he
>adds, considering how slowly practices change in the food business, 10
>years aver such confirmatory data came in
>"sanitarians would probably still be requiring [retail establishments]
>to use plastic cutting boards."
>__________________________________________________________________
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__________________________________________________________________
This greenbuilding dialogue is sponsored by Oikos (www.oikos.com)
and Environmental Building News (www.ebuild.com). For instructions
send e-mail to greenbuilding-request@crest.org.
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