Food Safety Talk 118: Hand Size Matters

This episode has you covered from the top of your head to the tips of your lucky socks. Ben and Don dig into some 1980’s culture and shoot forward into the food on the future, and then back again. It’s a food (and pet) safety grab bag covering pineapple safety, hand sizes and hand sanitizers, safe raw cookie dough, rats, turtles, milk from camels, microgreens and toilet history.1485292970453

Episode 118 can be found here and on iTunes.

Here are some links so you can follow along at home.

Rutgers hit with noro outbreak

Some Rutgers University students had a nasty gastrointestinal illness last week that is likely norovirus, according to the Daily Targum. Don and I talked about this outbreak on the podcast today. Rutgers has a few things working for them: the semester is over (leaving lots of time to clean and sanitize; and less places for the virus to be transmitted), and Schaffner is there providing some technical advice.

At least 35 students are complaining of feeling sick after a suspected virus broke out on campus around Dec. 7.10849902_719581291471357_3442145704847569295_n1-300x3001-300x300-1

Many of these students, who claim to have eaten in the Livingston and Brower Dining Halls, believe they are suffering from food poisoning. But University Sanitarian John Nason said he does not think this is a food-borne illness.

“The virus is people-to-people. We don’t believe it’s food-borne,” he said. “Most people are getting sick 90 minutes to two hours after eating, which doesn’t make sense. Most people who get sick after eating think it’s food poisoning.”

He said the onset time of 90 minutes to two hours does not equivocate to a food-borne virus, considering viruses such as E. coli and salmonella have an onset time of about six to 48 hours.

Managing a norovirus outbreak is a bit tricky, here are a couple of infosheets we’ve used/developed over the years that might be of use.

Norovirus is a problem for campuses and cafeterias

Vomiting and fecal episodes

Food Safety Talk 115: Features Chico Marx

It’s the super happy holiday version of Food Safety Talk. Don and Ben chat about Christmas movies, gambling as children and other holiday traditions. Making appearances in the guys’ discussion are Twitter and posting great questions of regulators about poor recall notices; cooling and holding cous cous and regulatory interpretations of time as a public health control; norovirus outbreaks at schools; and, Chipotle’s food safety culture.marx-brothers-harpo-marx-chico-marx-groucho-marx1

Episode 115 can be found here and on iTunes.

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Food Safety Talk 113: A Tale of Two Outbreaks

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.english-novelist-charles-dickens

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.

Episode 113 can be found here and on iTunes.

Show notes so you can follow along at home:

Food Safety Talk 112: Magical little poop nugget

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.1479398141136

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.

Episode 111 can be found here and on iTunes.

Show notes so you can follow along at home:

This birthday themed episode features wide-ranging topics, many based on listener feedback. We briefly touch on election results, and then move (almost) right into food safety. Thanks to everyone for listening and for your feedback.

Food Safety Talk 111: The Meat Spot

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.slide-image-1

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.

Episode 111 can be found here and on iTunes.

Show notes so you can follow along at home:

Food Safety Talk 109: Pooped on an airplane

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.14502823_10157592450435442_3811567674478483849_n

Episode 109 can be found here and on iTunes.

Show notes so you can follow along at home:

Schaffner does science: ‘Five second rule’ for food on floor is untrue, study finds

Friend of the barfblog.com Don Schaffner of Rutgers is having his pop-science moment in the sun.

schaffner-facebook-apr-14And he did it right.

Press release before peer-review, whatever faults peer-review has, is a bad idea.

(My previous lab had our moment in 2004 when we trashed food safety practices on TV cooking shows; it was peer-reviewed before we talked about it.)

So Schaffner and graduate student Robyn Miranda, waited until their results were published, and then destroyed the 5-second rule: you know, food is safe if it’s on the floor for less than 5-seconds.

Christopher Melesept of the N.Y. Times reports a new study debunks the so-called five-second rule.

Professor Donald W. Schaffner, a food microbiologist at Rutgers University in New Jersey, said a two-year study he led concluded that no matter how fast you pick up food that falls on the floor, you will pick up bacteria with it.

The findings in the report — “Is the five-second rule real?” — appeared online this month in the American Society for Microbiology’s journal,Applied and Environmental Microbiology.

Researchers at Aston University’s School of Life and Health Sciences in England reported in 2014 that food picked up a few seconds after being dropped is “less likely to contain bacteria than if it is left for longer periods of time,” giving rise to news accounts suggesting that eating the food might be harmless. Those findings, and research done at the University of Illinois in 2003, did not appear in a peer-reviewed journal, Professor Schaffner noted.

Even though the five-second rule is a bit of folklore, it still raised important public health issues that demanded closer scrutiny, he said. He cited research by the Centers for Disease Control, which found that surface cross-contamination was the sixth most common contributing factor out of 32 in outbreaks of food-borne illnesses.

5-second-ruleProfessor Schaffner and a master’s thesis student, Robyn C. Miranda, tested four surfaces — stainless steel, ceramic tile, wood and carpet — and four different foods: cut watermelon, bread, buttered bread and strawberry gummy candy. They were dropped from a height of five inches onto surfaces treated with a bacterium with characteristics similar to salmonella.

The researchers tested four contact times — less than one second and five, 30 and 300 seconds. A total of 128 possible combinations of surface, food and seconds were replicated 20 times each, yielding 2,560 measurements.

The research found that the five-second rule has some validity in that longer contact times resulted in transfer of more bacteria. But no fallen food escaped contamination completely. “Bacteria can contaminate instantaneously,” Professor Schaffner said in a news release.

Carpet had a very low rate of transmission of bacteria compared with tile and stainless steel; transfer rates from wood varied.

The composition of the food and the surface on which it falls matter as much if not more than the length of time it remains on the floor, the study found. Watermelon, with its moisture, drew the highest rate of contamination and the gummy candy the least.

In an interview, Professor Schaffner said, “I will tell you on the record that I’ve eaten food off the floor.” He quickly added: “If I were to drop a piece of watermelon on my relatively clean kitchen floor, I’m telling you, man, it’s going in the compost.”

The history of the five-second rule is difficult to trace but it is attributed apocryphally to Genghis Khan, who declared that food could be on the ground for five hours and still be safe to eat, Professor Schaffner said.

William K. Hallman, an experimental psychologist and a professor at the Department of Human Ecology at Rutgers University, said people do not put every decision through a risk-benefit filter and instead rely on cognitive shortcuts called heuristics to help in their daily lives.

“It’s a way of making a very quick decision with whatever data is available,” he said in an interview.

But sometimes those shortcuts can be based on flawed assumptions or missing information.

For instance, germs are invisible and so they are easy to ignore when “something of particular value, like a yellow peanut M&M” falls to the floor, he said. Because germs are out of sight, the belief is there is no harm in picking up the M&M and popping it in your mouth.

celebrity-chefsDouglas Powell, a former professor of food safety and the publisher of barfblog.com about food safety, added that people eat from the floor because they are told not to waste food.

People are also impervious to risk. “I’ve done this all my life and never gotten sick; I did this a couple of days ago and nothing happened,” he said in an email.

Or as Professor Schaffner observed: “The first kid, the pacifier falls on the floor, oh my God, we have to sterilize it. By the third kid, it’s like ‘whatever.’ ”

Research has shown that people think germs belong to other people, Professor Hallman said. For instance, people generally believe their bathrooms are cleaner than a public restroom. In fact, that is not the case because public restrooms are cleaned more regularly, he said in an interview.

People also misunderstand the transmission of germs.

“We sort of joke about the five-second rule, but people act as if germs take some period of time to race to the item that fell on the floor,” he said.

People also do not recognize the symptoms of food-borne illnesses and tend to blame them on the last thing they ate, so they do not connect how their earlier actions might have made them sick.

food-safety-asshole-schaffnerAre men more likely to eat off the floor than women?

Yes, according to Professor Hallman. In contrast to women, men say they more frequently engage in behaviors such as picking up food or a fork that has fallen to the floor, or picking an insect or a hair out of their food then continuing to eat, he said. The findings came from a phone survey of 1,000 Americans in 2005.

Anthony Hilton, a professor of microbiology at Aston University, said a survey of nearly 500 people found 81 percent of women said they followed the rule — they would not eat anything that lingered on the floor — compared with 64 percent of men, the magazine “Scientific American” reported.

“Hilton says he doesn’t have a good explanation for this gender differentiation but points out that this finding is consistent with other research into the five-second rule,” the magazine wrote. “One possible conclusion: This is tacit confirmation of another piece of folk wisdom — men are less discerning when it comes to their food’s cleanliness.”

 

A systematic look at the five-second rule: Miranda and Schaffner edition

When I meet someone who asks what I do the conversation usually turns to restaurant grades, foods I avoid and the famed 5-second rule. Most have an opinion that confirms their actions (where benefit may outweigh risk depending on what was dropped).

Paul Dawson and colleagues looked at the five-second rule in 2007 showing greater transfer with longer drying times with an 8 hour drying period of the floor contaminant. In 2014 a group of students at Aston University in Birmingham, U.K conducted some science-fair type experiments and reported the non peer-reviewed research on their university website. It got picked up all over the place and for 15 minutes the question was answered; everyone could go back to dropping their food on the floor and setting the critical limit at <5 seconds.giphy

Rutgers graduate student Robyn Miranda and friend of barfblog (and podcast co-host extraordinaire) Don Schaffner tackled the 5-second rule in a more systematic way and put out a press release today after the paper went through peer-review and was published (cuz that’s how Schaffner rolls). The quick answer to whether the oft-cited risk prevention step is a myth? ‘The five-second rule is a significant oversimplification of what actually happens when bacteria transfer from a surface to food. Bacteria can contaminate instantaneously.’

Turns out bacteria may transfer to candy that has fallen on the floor no matter how fast you pick it up.

Rutgers researchers have disproven the widely accepted notion that it’s OK to scoop up food and eat it within a “safe” five-second window. Donald Schaffner, professor and extension specialist in food science, found that moisture, type of surface and contact time all contribute to cross-contamination. In some instances, the transfer begins in less than one second. Their findings appear online in the American Society for Microbiology’s journal, Applied and Environmental Microbiology.

“The popular notion of the ‘five-second rule’ is that food dropped on the floor, but picked up quickly, is safe to eat because bacteria need time to transfer,” Schaffner said, adding that while the pop culture “rule” has been featured by at least two TV programs, research in peer-reviewed journals is limited.

“We decided to look into this because the practice is so widespread. The topic might appear ‘light’ but we wanted our results backed by solid science,” said Schaffner, who conducted research with Robyn Miranda, a graduate student in his laboratory at the School of Environmental and Biological Sciences, Rutgers University-New Brunswick.

The researchers tested four surfaces – stainless steel, ceramic tile, wood and carpet – and four different foods (watermelon, bread, bread and butter, and gummy candy). They also looked at four different contact times – less than one second, five, 30 and 300 seconds. They used two media – tryptic soy broth or peptone buffer – to grow Enterobacter aerogenes, a nonpathogenic “cousin” of Salmonella naturally occurring in the human digestive system.

Transfer scenarios were evaluated for each surface type, food type, contact time and bacterial prep; surfaces were inoculated with bacteria and allowed to completely dry before food samples were dropped and left to remain for specified periods. All totaled 128 scenarios were replicated 20 times each, yielding 2,560 measurements. Post-transfer surface and food samples were analyzed for contamination.

Not surprisingly, watermelon had the most contamination, gummy candy the least. “Transfer of bacteria from surfaces to food appears to be affected most by moisture,” Schaffner said. “Bacteria don’t have legs, they move with the moisture, and the wetter the food, the higher the risk of transfer. Also, longer food contact times usually result in the transfer of more bacteria from each surface to food.”

Perhaps unexpectedly, carpet has very low transfer rates compared with those of tile and stainless steel, whereas transfer from wood is more variable. “The topography of the surface and food seem to play an important role in bacterial transfer,” Schaffner said.

So while the researchers demonstrate that the five-second rule is “real” in the sense that longer contact time results in more bacterial transfer, it also shows other factors, including the nature of the food and the surface it falls on, are of equal or greater importance.

“The five-second rule is a significant oversimplification of what actually happens when bacteria transfer from a surface to food,” Schaffner said. “Bacteria can contaminate instantaneously.”

The paper can be downloaded here, abstract below.

 

WORLD: Longer contact times increase cross-contamination of Enterobacter aerogenes from surfaces to food
02.sep.16
Appl. Environ. Microbiol. DOI: 10.1128/AEM.01838-16
Robyn C. Miranda and Donald W. Schaffner
Bacterial cross-contamination from surfaces to food can contribute to foodborne disease. The cross-contamination rate of Enterobacter aerogenes was evaluated on household surfaces using scenarios that differed by surface type, food type, contact time (<1, 5, 30 and 300 s), and inoculum matrix (tryptic soy broth or peptone buffer). The surfaces used were stainless steel, tile, wood and carpet. The food types were watermelon, bread, bread with butter and gummy candy. Surfaces (25 cm2) were spot inoculated with 1 ml of inoculum and allowed to dry for 5 h, yielding an approximate concentration of 107 CFU/surface. Foods (with 16 cm2 contact area) were dropped on the surfaces from a height of 12.5 cm and left to rest as appropriate. Post transfer surfaces and foods were placed in sterile filter bags and homogenized or massaged, diluted and plated on tryptic soy agar. The transfer rate was quantified as the log % transfer from the surface to the food. Contact time, food and surface type all had a highly significant effect (P<0.000001) on log % transfer of bacteria. The inoculum matrix (TSB or peptone buffer) also had a significant effect on transfer (P = 0.013), and most interaction terms were significant. More bacteria transferred to watermelon (~0.2-97%) relative to other foods, while fewer bacteria transferred to gummy candy (~0.1-62%). Transfer of bacteria to bread (~0.02-94%) and bread with butter (~0.02-82%) were similar, and transfer rates under a given set of condition were more variable compared with watermelon and gummy candy.

 

Food Safety Talk 107: Univalve Mallets

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.1472063437005

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.

Episode 107 can be found here and on iTunes.

Show note links to follow along at home: