Fast Facts about Cutting Boards and Food Safety in Your Kitchen (from The Abstract)

Channeling my inner Dean Cliver, I had a chat last week with my friend Matt Shipman about cutting boards and food safety. Matt, a science writer, public information officer at North Carolina State University, curator of The Abstract, and all around swell dude, writes:

Anything that touches your food can be a source of contamination and foodborne illness – including cutting boards.

For example, if you cut up a raw chicken, and then use the same cutting board to slice a tomato for your salad, you run the risk of cross-contamination – with bacteria from the chicken being transferred to the tomato. That, of course, would be bad.

And vegetarians aren’t off the hook either. Fruits and vegetables can also carry pathogens (and transfer them to cutting boards).

To reduce the risk of foodborne illness in your kitchen, here are some things you should know about cutting boards.

Plastic Versus Wood

For a long time, most (if not all) cutting boards were made of wood. But at some point people began using plastic cutting boards. The idea was that they were easier to clean (and sanitize), and therefore were safer.

But in the late 1980s, a UC Davis researcher named Dean Cliver – the de facto godfather of cutting board food safety – decided to investigate whether plastic cutting boards really were safer. Answer: not really.

Photo credit: Betsssssy, via Wikimedia Commons.

Plastic cutting boards, Cliver found, are easier to sanitize. But cutting on them also leaves lots of grooves where bacteria can hide. Wood is tougher to sanitize, but it’s also (often) tougher in general – you won’t find as many deep scratches in the surface.

In addition, researchers have discovered that the type of wood your cutting board is made from also makes a difference.

“Hardwoods, like maple, are fine-grained, and the capillary action of those grains pulls down fluid, trapping the bacteria – which are killed off as the board dries after cleaning,” says Ben Chapman, a food safety researcher at NC State. “Soft woods, like cypress, are less likely to dull the edge of your knife, but also pose a greater food safety risk,” Chapman explains. “That’s because they have larger grains, which allows the wood to split apart more easily, forming grooves where bacteria can thrive.”

Which type of cutting board should you use? Chapman recommends using plastic cutting boards for meat and wood cutting boards for fruit, vegetables, or any ready-to-eat foods (like bread or cheese).

Why use plastic cutting boards for meat? Because of how you wash them.

Cleaning Your Cutting Board

Plastic and wood have different characteristics, so you have to handle them differently.

Plastic cutting boards can be placed in the dishwasher, where they can be sanitized by washing at high temperatures. But wood cutting boards would quickly be ruined by a dishwasher, and not everyone owns a dishwasher. If you’re washing a cutting board by hand, you should:

  • Rinse the debris off the cutting board (being careful not to splatter contaminated water all over the place);
  • Scrub the cutting board with soap and water (to get out anything in the scratches or grooves on the board’s surface); and
  • Sanitize the cutting board (you should use different sanitizers for wood cutting boards than for plastic ones).

For plastic cutting boards, you should use a chlorine-based sanitizer, such as a solution of bleach and water (one tablespoon of bleach per gallon of water – has a shelf life of a week or two). But for wood cutting boards, you should use a quaternary ammonia sanitizer, such as a solution of Mr. Clean and water (follow the dilution instructions on the label).

“This is because chlorine binds very easily to organic materials, like the wood in a cutting board, which neutralizes its antibacterial properties,” Chapman says. “Quaternary ammonia is more effective at killing bacteria on wood or other organic surfaces.”

It’s worth noting that you should also sanitize your kitchen sponge/rag/brush after you’ve used it to scrub the chicken-juice off your cutting board – or else you run the risk of contaminating the next thing you wash (which is the exact opposite of what you’re trying to do).

The last step in cleaning your cutting board is an important one –dry it.

“Make sure you put the cutting board somewhere that air circulates, so that it can dry completely,” Chapman says. Bacteria need moisture to grow, and you don’t want to give them a welcoming environment.

“Historically, butchers used to put salt on their butcher blocks to keep them from smelling bad,” Chapman says. “This worked because the salt drew the moisture out of the wood and prevented bacterial contamination, which is what caused the smell – though the butchers didn’t know it at the time.”

When To Replace Your Cutting Board

At some point, scrubbing and sanitizing might not be enough. When your cutting board has accumulated a lot of deep grooves from repeated use, you probably need to replace it.

“The more grooves it has, and the bigger they are, the more area is available for trapping moisture and giving bacteria a place to proliferate,” Chapman says.

Food safety leader Dean Cliver passes away

Dr. Dean Otis Cliver, born March 2, 1935, died Monday, May 16, 2011, at his home in Davis, California.

A graduate of Purdue University with bachelor’s and master’s degrees, Dean completed his Ph.D. at Ohio State University in the spring of 1959. He was a professor at the University of Wisconsin in Madison in the Food Research Institute from 1962 to 1995 and was a professor at UC Davis from 1995 to 2008, continuing as a professor emeritus until his recent illness.

Dean was a respected and widely published member of the worldwide scientific community, with his work taking him to countries in Europe, Asia, North and South America. In his work with foodborne diseases Dean was often called for information by members of the media, as he was known for his ability to make science understandable to non-scientists. He was a long-time IFT scientific communicator and regularly worked with the media providing information on food safety practices (particularly recognized for research on cutting boards), food irradiation, and BSE (mad cow disease).

He was known for his research on virology and from 1969 was a consultant to the World Health Organization on virus transmission in foods. He and his wife Carolyn opened their home to many foreign students who later became part of their extended family.

I didn’t know Dean that well, but he would e-mail me frequently about the food safety issues of the day. He contributed to in 2008, and came up with the most apt bio I’ve had the pleasure of publishing:

“Dr. Cliver officially retired October 1, 2007 and is winding down from 46 years in academia, battling infectious agents in food and water. His research career has led him to see the world as if peering outward through the anal orifice: this ‘reverse proctoscopy’ confers a unique viewpoint.”

He will be missed.

Dean Cliver responds to Rachael Ray 20 years earlier

Rachael Ray (right, sampling goods in Florida last weekend) offered up some suggestions for so-called healthier cooking in that annoying USA Weekend insert to many local newspapers, including this gem:

"Look at labels. … If you can’t read an ingredient, chances are you should not be putting it in your body."

Dr. Dean Cliver, who officially retired October 1, 2007 and is winding down from 46 years in academia, battling infectious agents in food and water, realized that he had come up to the solution to this very problem some 20 years ago and decided to once again share his thoughts with Dr. Cliver’s proposed label is left, bottom.

The following was originally published in University of Wisconsin-Madison AG LIFE LINES, College of Agricultural and Life Sciences, Vol. 4, No. 2, page 6, and republished in the Journal of Irreproducible Results, Vol. 34, No. 4, Mar-Apr 1989, page 18.

A subtle and probably pernicious trend in the U.S. food supply seems to be occurring virtually unnoticed.  If one reads the information on a food package, as it seems few do, one finds that many food in the U.S. today are composed almost entirely of ingredients.  The use of ingredients in foods has become so widespread and flagrant that one can hardly guess what will appear next on the growing list of polysyllabic horrors printed on packages.  Through insouciance or ineptitude, we have let the situation get quite out of hand.

Labels seem to be intended rather to obfuscate than to inform.  Aside from water, which evidently abounds in these products (though who knows where it has been before it goes into the food?), hardly any of the names that appear on these lists are comprehensible to the average consumer or even pronounceable.  The acronyms are even worse.  It is not enough to know that “BHA” stands for “butylated hydroxyanisol.”  How are we to know where and by whom the hydroxyanisole we are about to ingest was butylated or whether the hydroxyanisole itself was natural or synthetic? 

Though most consumers apparently do not read labels at all, those who do seem to have become jaded.  My son asked me recently whether the “regular”-flavored generic toothpaste we had just purchased contained natural or artificial regular.  And what about the blind — should lists also appear in Braille?

There is little doubt that most of these ingredients are harmful, at least at some level, in foods.  Why, for example, would salt be listed as “sodium chloride” if there were nothing to hide?  Would any of us willingly be called “The Sodium Chloride of the Earth"?  Sugar now comes in enough forms to confound the ablest pancreas.  Fats are listed as though they were all polyunsaturated, without any indication of the degree of polity.  Plain, American English is nowhere to be found.

Not only are we consuming ingredients ourselves, but we are inflicting them on our unsuspecting children, mindless of potential harm to all future generations.  Small wonder that behavioral problems abound in the society whose children have been fed ingredients virtually from birth!  For example, many young people today are probably essentially addicted to calcium propionate in their bread.  What becomes of them if their supply is cut off?  Packages marked “no preservatives” should probably be viewed with extreme caution.

Time and the press have made it clear that the predominance of ingredients in U.S. foods is largely due to the greed of profit-hungry food manufacturers.  There is little doubt that this is true: if one travels to parts of the world where the profit motive has been outlawed, one finds that foods are virtually free of ingredients.  This has such a favorable effect on quality that people are willing to stand in long lines for food every day.  By contrast, hardly anyone stands in line to get food in the U.S. — with all those ingredients why bother?

I submit that the time has come for action on this matter.  Consumer groups and enlightened members of the general public must bring pressure to bear on Congress and the U.S. Food and Drug Administration to mandate reduced levels of ingredients in foods, probably with a view to an eventual complete ban.  Nowadays, virtually the only food one can buy that is almost certainly free of ingredients is an egg in its original shell, and we are now being told not to eat more than one of them per week.  How are we to survive on such a diet?

American food manufacturers, in their cupidity, must not be allowed to continue perpetrating this sesquipedalian atrocity on the indifferent or benighted public.  Let us speak out now, so that those in government will recognize their duty to regulate, reduce, and eventually eliminate ingredients from the US food supply!  Let’s get the American public back on real, ingredient-free food, before accumulated subtle deficiencies and abnormalities put us all under the table to stay.  Our posterity and their posterity demand this of us.

Dr. Dean Cliver: Eggs deluxe

Dr. Dean Cliver writes in this satirical contribution that:

My supermarket charges a 34% premium for "cage-free" eggs, compared to conventional eggs of the same brand, size, and grade.  Cage-free eggs, with additional features, get as much as a 124% surcharge.  Some say that eggs from cage-free chickens have more flavor because the chickens eat bugs; it would probably be cheaper to raise insects and feed them to layers in conventional cages, although the chicken would be denied the thrill of the chase. 

I suspect that most people who pay extra for cage-free eggs would not be able to detect the difference in taste, which suggests that flavor is not what they are really paying for.  More likely, the premium is paid out of respect for the hens’ freer lifestyle.  If respect for chickens adds value to their eggs, there are certainly further commercial possibilities based on enhancing the life of the chicken.

I suggest that, if laying hens are to be treated with the dignity they deserve, premium egg ranches give every chicken her own name.  As each egg was produced, its shell would be imprinted with the donor’s name.  In the interest of marketing eggs as fresh as possible, no two eggs in a one-dozen carton would bear the same name; the names might also be embellished with colors and distinctive logos. 

Hens typically proclaim their egg production with the characteristic, triumphant cackle — it should be possible to build this into each egg carton (as is now done in greeting cards and other devices), so that the purchaser would hear it each time the carton was opened.  Value might be further enhanced by adding some scratch-and-sniff barnyard aroma (bacteria-free, of course), to give the consumer an even greater feeling of being close to Nature.

How much value would be added by these measures could be determined by market research.  If the prognosis was sufficiently favorable, there should be little difficulty capitalizing the required egg ranch and processing facility.  Hens that "graduated" from such a ranch might also have added gastronomic value, or they might simply be enrolled in an alumnae association for life.

Dr. Cliver officially retired October 1, 2007 and is winding down from 46 years in academia, battling infectious agents in food and water.  His research career has led him to see the world as if peering outward through the anal orifice: this "reverse proctoscopy" confers a unique viewpoint.