Ben Chapman

About Ben Chapman

Dr. Ben Chapman is an associate professor and food safety extension specialist at North Carolina State University. As a teenager, a Saturday afternoon viewing of the classic cable movie, Outbreak, sparked his interest in pathogens and public health. With the goal of less foodborne illness, his group designs, implements, and evaluates food safety strategies, messages, and media from farm-to-fork. Through reality-based research, Chapman investigates behaviors and creates interventions aimed at amateur and professional food handlers, managers, and organizational decision-makers; the gate keepers of safe food. Ben co-hosts a biweekly podcast called Food Safety Talk and tries to further engage folks online through Instagram, Twitter, Facebook, YouTube and, maybe not surprisingly, Pinterest. Follow on Twitter @benjaminchapman.

NPR says take the fear out of mayonnaise: make it with raw egg yolks and a splash of boiling water

I’m not sure who fears mayonnaise, but Chef Simon Hopkinson tells NPR’s The Salt that folks do, and they shouldn’t if they follow his kitchen hacks.

“mayonnaise … is something that is such a pleasure to make, but people are often frightened of it and it’s one of the most delicious things.”

Hopkinson has two secrets for making mayonnaise at home. The first one is to spare your arms and use an electric whisk. The second secret is use a tall, narrow beaker, or a small pitcher, not a wide bowl. That way everything stays in one place and doesn’t splatter.IMG_4944

You start with two egg yolks, a blob of dijon mustard, a squeeze of lemon, salt and white pepper.

Throw that into the beaker and whisk it around a bit. Then comes the oil – he uses a mix of olive oil and peanut oil.

One final touch: a splash of boiling water to smooth the taste.

I’ve made dishes that call for raw eggs stuff like mayo, meringue and caesar salad dressing. The third tip Hopkinson misses is to use in-shell pasteurized eggs to reduce Salmonella Enteriditis risks; a pathogen worth fearing. There have been lots of raw egg dish-linked Salmonella outbreaks.

The boiling water won’t raise the temperature high enough to kill any pathogens. I just did a bit of a home science experiment. Just added a splash of boiling water, which I defined as a tablespoon, to half a cup of room temperature yogurt, my mayonnaise surrogate, and the temperature went up 6 degrees (77F to 83F). It took 3/8 of a cup of boiling water to get the mixture above 135F and resulted in a milky consistency.

Leafy greens carry risks; at-home rinsing of pre-washed salad mix isn’t doing much

In the quest to get healthier, including losing weight and reducing my body fat percentage, I’ve been paying particular attention to my eating habits and eating a bunch more vegetables.

I’ve become increasingly fond of the convenience of pre-washed, bagged, fresh whatever. A staple of my weekly meals is 4oz of steak, a crumble of blue cheese, grilled mushrooms, sliced pear, a few walnuts all over a bed of 50/50 mix of pre-washed baby spinach and and mesclun mix.img86l

I just open the bag and throw it on the plate. Because there’s not much I can do, safety-wise, to it once it’s in my home. If there’s pathogenic E. coli, Listeria or Salmonella there (or others) I’m stuck with it. I’m following recommendations from a bunch of my food safety friends who reviewed the literature on cut, bagged, washed, ready-to-eat leafy greens from a few years ago. In the abstract, they write:

The panel concluded that leafy green salad in sealed bags labeled “washed” or “ready-to-eat” that are produced in a facility inspected by a regulatory authority and operated under cGMPs, does not need additional washing at the time of use unless specifically directed on the label.

Leafy green food safety risks need to be addressed before they get to me, all I can do by washing it again is increase the chance I cross-contaminate the salad precursor in my home. My purchasing choice is based in trust that growers, packers and processors know what they are doing, and do it. But at best, they can only remove 90% of what is there with a wash.

Last week some research was presented at the American Chemical Society National Meeting & Exposition, prior to peer-review, that states what lots of food safety folks have published over the past decade: washing leafy greens doesn’t result in a sterile salad and the bumpy leaves protect pathogens.


I talked to Korin Miller at Yahoo News about it,

Labels like “thoroughly washed” and “triple washed” make us feel comfortable chowing down on pre-washed baby spinach straight from the container. But researchers from the University of California, Riverside, say we might want to rethink that habit.

They discovered that the small peaks and valleys in baby spinach leaves can harbor bacteria — even during the washing process they often undergo in food-processing plants.

While the news is shocking to most people, “this is not a surprise to many of us in the food safety arena,” Mike Doyle, director of the Center for Food Safety at the University of Georgia, tells Yahoo Health.

Unfortunately, washing your pre-washed baby spinach before eating it doesn’t make a difference, says Benjamin Chapman, PhD, an assistant professor and food safety extension specialist at North Carolina State University.

“Rinsing isn’t going to do a whole heck of a lot for food safety,” Chapman tells Yahoo Health — it just may remove dirt or other physical objects that you can see. Cooking the spinach, however, will kill potentially harmful bacteria.

I don’t agree with this comment, ‘pre-washed baby spinach is typically treated using a bleach disinfectant’

But what about the whole “triple wash” label? Does that make pre-washed spinach safer? Chapman says there’s some confusion about what it means. Companies don’t triple wash spinach to disinfect it, he explains — they do it to reduce the likelihood of cross-contamination from one piece of spinach to another during the washing process.

The water is treated to reduce cross-contamination in the processing water; 2-log reduction, at the very best, is not an effective surface disinfectant.

The vomit machine, not just for parties; useful for modeling norovirus

I’ve been lucky to be close to some excellent projects, some of the stuff and knowledge created through these projects ends up mattering to food safety nerds – especially those who are making risk management decisions. NC State student Grace Tung-Thompson’s PhD project on vomit spray and norovirus is one of the most impactful. The work was carried out as part of the USDA NIFA-funded NoroCORE project led by my friend Lee-Ann Jaykus.VOMIT-BLOG-HEADER-698x393

I’ve talked to lots of Environmental Health Specialists, retailers and food service food safety folks about what Grace and fellow graduate student Dominic Libera put together and many respond with a weird level of enthusiasm for the barf project.

Mainly because a real question they struggle with is how far will virus particles travel from an up-chuck event – knowing this, and then cleaning and sanitizing helps limit the scope of a potential outbreak. Today Grace’s work was published in PLOS ONE.

Matt Shipman, Research Communications Lead for University Communications and all around great guy writes about the project for The Abstract:

Tucked away in a quiet lab on NC State’s Raleigh campus is something that looks like a glorified air compressor with a grotesque clay face. It’s called “the vomiting machine” and it does exactly what you think it does. Researchers are using it to study one of the most widespread pathogens in the United States: norovirus.

Norovirus is a group of more than 30 related viruses that can cause vomiting and diarrhea. Norovirus affects about 20 million people each year in the U.S., with infections that can lead to hospitalization and occasionally to death, particularly in the elderly. About a quarter of the time, “noro” infection is obtained by consuming contaminated foods or water.  However, it is most often spread between people in close contact with each other.  The epidemic GII.4 strain predominates, but there are others.

But how, exactly, is noro transmitted from person to person?

“Epidemiological studies have suggested that norovirus can be ‘aerosolized’ through vomiting, meaning that small particles containing norovirus can become airborne when someone throws up,” says Grace Thompson, a recent Ph.D. graduate whose work at NC State focused on how norovirus spreads through vomiting and how long it is detectable in vomit. (Fun fact: noro can still be detected in dried vomit after six weeks.)

“According to outbreak reports, it appears that people can become infected with noro if they are directly or indirectly exposed to vomiting events,” Thompson explains. “If aerosolized particles land on a countertop, you could also touch the counter with your hand, then touch your hand to your mouth, leading to infection.”

But while norovirus aerosolization by vomiting has long been suspected, no one knew if it was actually occurring. This is the sort of question that Lee-Ann Jaykus’s lab lives for.

Jaykus is a professor of food science at NC State and scientific director of the U.S. Department of Agriculture-National Institute of Food and Agriculture Food Virology Collaborative, also known as NoroCORE (short for Norovirus Collaborative for Outreach, Research, and Education). They are, quite simply, norovirus experts.

To see if vomiting could really aerosolize norovirus, researchers in Jaykus’s lab (including Grace Thompson) needed a controlled way to observe and study vomiting over and over again. They needed a vomiting machine.

As you may imagine, there is a limited demand for vomiting machines, so the researchers had to design and build their own. They found a partner in Dominic Libera, a graduate student in NC State’s civil, construction and environmental engineering department in Francis de los Reyes’s lab.  They also needed data upon which to build their model.  Dr. Kenneth Koch, a gastroenterologist with Wake Forest University, provided that expertise.

Working together, the researchers created a machine that is essentially a scaled-down version of the mouth, esophagus, and stomach – made of tubes and a pressure chamber that passes through a clay face to give it the correct vomiting angle. The machine is designed (using engineering similitude principles) to let researchers control the pressure and volume of the vomit, in order to mimic a range of natural vomiting behaviors. The whole thing is enclosed in a sealed plexiglas box and placed under a biosafety hood. (A short video of the machine can be seen here.)

Instead of vomit, the researchers use liquid solutions of different viscosities or thicknesses as “artificial vomitus” to reflect different stages of digestion. And, since they cannot use real norovirus, they used a bacteriophage called MS2, which is a virus that infects E. coli but is harmless to humans. MS2 is easy to culture and is a common stand-in for noro.

Putting The Machine To Work

In 2012 and 2013, the team did extensive testing of the machine, to make sure that it was scaled appropriately and worked the way they wanted it to. And in 2014, Thompson began using the machine for formal experiments.

And what did they find? Well, virus was indeed aerosolized.  Although the amount of MS2 aerosolized as a percent of total virus “vomited” was relatively low (less than 0.3 percent), vomit from infected people contains millions of particles. When the math is done, this means that the actual amount of virus particles aerosolized during a single vomiting event ranges from only a few into the thousands, perhaps more. (This work was recently published in PLOS ONE. More information on the findings is available here.)

“And that is enough to be problematic because it only takes a few, perhaps less than 20, to make a susceptible person ill” Jaykus says. “This machine may seem odd, but it’s helping us understand a disease that affects millions of people. This is work that can help us prevent or contain the spread of norovirus – and there’s nothing odd about that.”

Calling all norovirus: passenger forced to sit beside vomit on plane

I’ve encountered vomit in public a few times.

A few weeks ago a fellow food safety nerd and I sat on a Seattle train and watched a woman 20 ft away yack on the floor while her partner consoled her. My friend and I figured that we’d get noro just by being there (we didn’t).CMhGalfWUAAnNds

A few years ago my son threw up on a flight which led to a fascinating approach by Delta Airlines involving plastic bags to contain the risk and coffee pods to manage the smell.

According to BBC, a Rynair passenger was forced to sit next to a vomit pile on a flight from Gatwick to London this week.

A 24-year-old was forced to sit in the same aisle as vomit left by a previous passenger on a Ryanair flight from Gatwick to Dublin on Sunday.

Noel O’Hare noticed the smell and mess as soon as he sat down with his friends on the hour and a half flight.220px-Neilyounglandingonwatercover

He told Newsbeat the “unsightly mess” was on the ground mixed in with a bag and tissues.

Ryanair cabin staff told him that because Gatwick isn’t their base and their cleaners are in Dublin, it couldn’t be cleaned up until they arrived back in Ireland.

Spray and aerosolization of vomit particles makes being in that adjacent seat particularly fun. 50K+ direct subscribers

This is a picture of two furry cats and a cute kid. The Internet loves these.

Apparently the Internet is also good for food safety stuff.

I was introduced to Doug by Lindsay Core, a friend who had previously worked for him. Lindsay knew I was desperately looking for a job, and didn’t tell me much else; she just said “I think you two will get along.”sorenne-cats-aug-15

I didn’t really know what that meant, and had no other prospects.

I emailed him, we had an electronic conversation about molecular biology, and he hired me to pull news, alongside a crew of other students.

Pulling news way back then meant that we surfed through the tubes of the interweb for anything food risk-y (microbial food safety, BSE, GMO foods, animal disease) and the stories become the content for daily listservs that was sent out to over 10,000 folks interested in the public discussion. Powell had been doing this 1993.

With the advent of Google and other web apps listserv newsletters became passe and engagement was where we wanted to go.

When self-publishing was all the rage we decided to start a forum to share foodborne illness stories. Every time we talked to someone on a plane, train or automobile and they found out what we did (food safety stuff) they would proceed to share their worst illness story. We wanted to capture those stories, except most people don’t want to be bothered writing, so we did it for them.

But it needed a name.

After one not particularly notable midday pick-up hockey session we had a few beers  with some government- and professor-type friends and brainstormed names.

A creative undergraduate student, Christian Battista, came up with barfblog, and it stuck.

We write it all as one word, in lower case, because capital letters in email are a waste of time.

images-1The idea and technology morphed barfblog away from a just a forum and we created a space to take current news items and highlight what we thought was important – based on the literature and our experiences.

It’s collaborative, a space for discussion and engagement, with a benevolent editorial dictator.

Last week, around the same time we hit 11,000 posts, we surpassed 50,000 subscribers. That’s a lot of folks interested in food safety stuff.

We may not be able to compete with cat pictures, but we know microbial food safety – the things that make people barf.


Washington State whole hog salmonellosis cases linked to slaughterhouse

Growing up in Canada, barbecue was an event, or an outside cooking appliance. In North Carolina barbecue is a food.

And for some, sort of a religion.

Barbecue is made by slow cooking pork (often a whole hog) in a smoker for hours until the meat is tender enough to be pulled off of the bones. The kind I like is tossed in a vinegar and pepper sauce (that’s Eastern North Carolina style) and served with a couple of vegetable sides.

There’s a bunch of whole hog barbecue in Washington State too.

And, according to JoNel Aleccia of the Seattle Times, over 130 cases of salmonellosis have now been linked to whole roasted hogs sold from a Pierce County (WA) slaughter house.670px-Cook-a-Whole-Pig-Step-3

Samples collected from Kapowsin Meats in Graham last week tested positive for the rare outbreak strain of the bacteria, Salmonella I, 4, 5, 12:9:-, a germ that hasn’t been seen before in Washington state.

Officials cautioned there may be other sources. Exposure for many apparently came from whole roasted pigs served at private events and restaurants.

I want microbiologically safe, not ecologically clean food

Maybe something is lost in translation but according to the Bulgarian sheep-breeders association is telling folks not to eat raw meat or drink raw milk due to anthrax and brucellosis risks.

Biser Chilingirov, chairperson of Bulgaria’s National Sheep-breeding Association urged stock-breeders and farmers to wear wire mesh gloves when butchering animals to prevent themselves for getting cuts.shaun_the_sheep_wallpaper_border

Biser Chilingirov told people to purchase products directly from farms as they were “ecologically clean”. 

Not sure what that means but I’d like to see some data.

Cyclospora in Canada: PHAC and CFIA investigate

According to the Public Health Agency of Canada, over 80 Canadians are ill with Cyclospora and the source isn’t known. It’s also not clear whether these illnesses are linked to the 350+ cases of Cyclospora in Texas and elsewhere.

Related, or maybe not, who can tell, cilantro produced in Puebla, Mexico was banned from the U.S. a couple of weeks ago – after hundreds of Cyclospora illnesses going back to 2012.230px-Cyclospora_cayetanensis

The Public Health Agency of Canada is collaborating with provincial public health partners, the Canadian Food Inspection Agency, and Health Canada to investigate 83 Canadian cases of Cyclospora infections in Ontario, British Columbia, Alberta, and Quebec. The source of this outbreak is not yet known, and the Agency and its partners continue to investigate.

In Canada, a total of 83 cases have been reported in British Columbia (3), Alberta (1), Ontario (74), and Quebec (5). Two cases have been hospitalized, and are recovered or recovering. No deaths have been reported. Individuals became sick between May 9 and July 18, 2015. To date, no source has been identified. The investigation is ongoing.

The Public Health Agency of Canada is leading the human health investigation of this outbreak and is in regular contact with its federal and provincial partners to monitor and take collaborative steps to address the outbreak. Health Canada provides food-related health risk assessments to determine if the presence of a certain substance or microorganism poses a health risk to consumers. The Canadian Food Inspection Agency (CFIA) conducts food safety investigations into the possible food source of an outbreak. The Government of Canada will continue to update Canadians as new information related to this investigation becomes available.

So many questions – are the Canadians coordinating with U.S. officials who are investigating american Cyclospora illnesses? Are Canadians still getting cilantro from Puebla, Mexico? This is a weird statement at the bottom of the press release:

To date, no multi-jurisdictional outbreaks have been linked to produce grown in Canada.

What goes in the fridge for safety reasons and other tales

Evidence and perception aren’t often congruent in the food safety world. There are lots of examples from the pages of the Internet: Dirty bathrooms are an indicator of sanitation in the kitchen; pathogens won’t transfer in less than five seconds when food hits the floor; and, yogurt is dangerous if consumed after the best-before date are just a few.

K. Aleisha Fetters of Yahoo News connected with Schaffner and I on the difference between refrigeration for safety and keeping stuff cool for spoilage and quality reasons.

Here are some excerpts.k2-_bd216f83-0923-407e-aea5-f57dc7338ebc.v1

Ketchup: Can remain at room temperature.
Ever wondered why restaurants keep ketchup on their tables rather than back in the fridge? Because it won’t make you sick, says Benjamin Chapman, PhD, associate professor and food safety extension specialist at North Carolina State University. Ketchup is so acidic that it prevents the growth of harmful bacteria. It will spoil faster if left out on the counter, but it could still take months to turn bad.

Fruits and vegetables: It depends.
If you think about it, fruits and vegetables grow outside at temps far higher than room temperature. That’s why, when they are whole, they are safe on your counter. However, when you cut them (or in the case of lettuce, just tear their stems from the ground), you actually rip open the cells of the plant. This releases nutrients, water, and bacteria, and allows them to mingle with each other, says food microbiologist Donald W. Schaffner, PhD, distinguished professor at Rutgers University. For example, when you cut a tomato or avocado, you need to keep it in the fridge to prevent the growth of salmonella. However, it’s worth noting that listeria can grow (albeit slowly) at cold temps. That’s why, even if you keep cut melons in the fridge, you should throw them out or add them to the compost pile after four days, Chapman says.

Mayonnaise: Must be refrigerated.
Well, this one is really more of an “it depends,” but we’re going to suggest sticking it in the fridge just in case. Most store-bought mayo is acidic enough to keep on the counter without it growing bad-for-you bacteria all by itself. (That’s why fast-food joints can keep it out in pumps until it’s used up.) But, if you cut some veggies with a knife, and then stick that knife in your jar of mayonnaise, you could potentially introduce bacteria into the mayo that is able to grow at room temperature, Chapman says. Meanwhile, whatever the recipe, homemade mayo is generally not acidic enough to fend off pathogens.

Food Safety Talk 79: You’re Into Botulism Country (with Merlin Mann)

Food Safety Talk, a bi-weekly podcast for food safety nerds, by food safety nerds. The podcast is hosted by Ben Chapman and barfblog contributor Don Schaffner, Extension Specialist in Food Science and Professor at Rutgers University. Every two weeks or so, Ben and Don get together virtually and talk for about an hour.  They talk about what’s on their minds or in the news regarding food safety, and popular culture. They strive to be relevant, funny and informative — sometimes they succeed. You can download the audio recordings right from the website, or subscribe using iTunes.3024499-poster-p-meat

Merlin Mann joins Don and Ben for a discussion on food safety and cooking using science at home.

The episode starts off with a discussion on sous vide and time/temperature combinations for pathogen reduction.

The discussion goes to Harold McGee’s On Food and Cooking and the science of cooking, sensory and how heat changes food quality and safety. The guys talk about ground meats risks compared to intact muscle meats and then deconstruct risk assessments with bullet analogies. The guys move into pork and trichinosis and how risks have changed but messages stay sticky.

The show ends with a discussion on food safety myths, including confusing food safety and spoilage; storing butter on the counter and  ketchup in the refrigerator.

They decided to leave an in-depth discussion of Sloan for another day.