Using observation to evaluate training: Canadian High School edition

A couple of old friends Shannon Majowicz and Ken Diplock and colleagues from Waterloo, (that’s in Canada) are doing good work looking at food safety stuff with high school students- evaluating training efficacy using observation. They published their work demonstrating some sustained food safety behaviors following a training program, this month in the Journal of Food Protection.

Kenneth J. Diplock, Joel A. Dubin, Scott T. Leatherdale, David Hammond, Andria Jones-Bitton, and Shannon E. Majowicz. 2018. Observation of High School Students’ Food Handling Behaviors: Do They Improve following a Food Safety Education Intervention?

Greenbank High School Birkdale Merseyside.

Journal of Food Protection: June 2018, Vol. 81, No. 6, pp. 917-925

Youth are a key audience for food safety education. They often engage in risky food handling behaviors, prepare food for others, and have limited experience and knowledge of safe food handling practices. Our goal was to investigate the effectiveness of an existing food handler training program for improving safe food handling behaviors among high school students in Ontario, Canada. However, because no schools agreed to provide control groups, we evaluated whether behaviors changed following delivery of the intervention program and whether changes were sustained over the school term. We measured 32 food safety behaviors, before the intervention and at 2-week and 3-month follow-up evaluations by in-person observations of students (n = 119) enrolled in grade 10 and 12 Food and Nutrition classes (n = 8) and who individually prepared recipes. We examined within-student changes in behaviors across the three time points, using mixed effects regression models to model trends in the total food handling score (of a possible 32 behaviors) and subscores for “clean” (17 behaviors), “separate” (14 behaviors), and “cook” (1 behavior), adjusting for student characteristics. At baseline, students (n = 108) averaged 49.1% (15.7 of 32 behaviors; standard deviation = 5.8) correct food handling behaviors, and only 5.5% (6) of the 108 students used a food thermometer to check the doneness of the chicken (the “cook” behavior). All four behavior score types increased significantly ∼2 weeks postintervention and remained unchanged ∼3 months later. Student characteristics (e.g., having taken a prior food handling course) were not significant predictors of the total number of correctly performed food handling behaviors or of the “clean” or “separate” behaviors, and frequency of cooking and self-described cooking ability were the only characteristics significantly associated with food thermometer use (i.e., “cook”). Despite the significant increase in correct behaviors, students continued to use risky practices postintervention, suggesting that the risk of foodborne disease remained.

Modeling food held out on a hot day

The unofficial start of the summer is this weekend in the U.S. – Memorial day. Folks will be bbqing, cooking out, grilling out, whatever.

There’s a recommendation from USDA that on a hot day, above 90F/32C that food shouldn’t sit out for more than an hour. I couldn’t find a good reference for this. So I started texting Don.

He wasn’t answering. (I found out later it was because he was doing an interview with CBC, that’s a radio/TV network in Canada).

I started looking at a Conference for Food Protection document on how to handle food decisions at retail when the power goes out. Not exactly what I was looking for – all the modeling starts at 41F and doesn’t get as hot as I was looking for.

Then Don finally answered and suggested this paper on Salmonella in cut tomatoes.

Getting warmer.

I finally got into Combase and generated a couple of no-lag growth models for staph (in something like potato salad) and Salmonella. 

The staph model doesn’t go as high as 90F/32C so it’s a bit conservative different. But the Salmonella model shows a 1 log increase in just over an hour.

So yeah, hot days matter.

 

Improving food safety, one thermometer at a time

Sorenne and I were walking home from school yesterday, sweating in the heat and humidity, and were waiting at a light with a young woman who had just got off work at an early childcare place that Sorenne used to attend.

I started up a conversation — it’s a long light – and she told me she had finished university and was taking a gap year, so had to pay the bills and was working.

I asked her what she was planning to do and she matter-of-factly said, “A PhD in clinical psychology.”

“That’s cool, I’ve got a PhD.”

“Oh, what in?”

“Food science, or food safety.”

“I remember you now. You were the parent who was always temping things with a thermometer when we had sausage sizzles.”

“Yup.”

“That was cool.”

Thanks to the barfblog.com community who has wrote back after my personal post about depression and the like.

The little things make a big difference.

Chapman, I need more thermometers.

 

Salmon sushi: 5.6′ tapeworm excreted by California man

Raw can be risky.

Including raw fish used to make sushi, especially if it is not frozen at sea.

Following up my chat with daughter Sorenne while strolling around Noumea, New Caledonia last week, a Fresno man with a daily sushi habit had a 5.5-foot tapeworm lodged in his intestines. He pulled it out himself, wrapped it around a cardboard toilet paper tube and carried the creature into Fresno’s Community Regional Medical Center.

Michelle Robertson, a San Francisco Gate staff writer, reports that Kenny Banh was the lucky doc on shift at the time. He recounted his experience on a recent episode of the podcast “This Won’t Hurt A Bit.”

Banh said the patient complained of “bloody diarrhea” and expressed a desire to get treated for tapeworms.

“I get asked this a lot,” the doctor said. “Truthfully, a lot of times I don’t think they have it.”

This man had it, which he proved to Banh by opening a plastic grocery bag and pulling out the worm-wrapped toilet paper tube.

Banh then asked some questions, starting with: “That came out of your bottom?”

“Yes.”

According to the doctor’s retelling, the patient was using the restroom when he noticed what looked like a piece of intestine hanging out of his body.

 “He grabs it, and he pulls on it, and it keeps coming out,” Banh recounted. He then picks the thing up, “looks at it, and what does it do? It starts moving.”

That’s when the man realized he had a tapeworm stuck in his insides. He headed to the emergency room shortly thereafter, where Banh treated him with an anthelmintic, a single-treatment deworming medication used on humans and dogs alike.

Banh also took it upon himself to measure the specimen on the floor of the hospital. It stretched a whopping 5 feet, 6 inches — “my height,” noted the doctor.

Tapeworms can be contracted in a variety of ways, but Banh said his patient hadn’t traveled out of the country or engaged in any out-of-the-ordinary behavior. The man also professed his love of sushi, specifically raw salmon sashimi, which he confessed to eating daily.

Fresno is located an ample 150 miles from coastline and is not exactly famed for its sushi. The Centers for Disease Control and Prevention warned last February that the rise in popularity of raw fish consumption has likely spurred

The story has attracted attention all over the world, as these things tend to do, says Peter Olson, a tapeworm expert and a researcher at the Natural History Museum’s life sciences department, who was quoted as telling The Guardian, “because they’re gross”. The worm, he says, was “almost certainly something called the broad fish tapeworm … salmon is one of the main ways you would pick it up, if you don’t cook the meat.” The life of the broad fish tapeworm involves more than one host. “A typical life cycle might include a bear that feeds on salmon, then defecates back into the river. The larvae would be passed into the environment and, in the case of an aquatic life cycle like this, it would be eaten by something like a copepod, a little crustacean. When that copepod is eaten by a fish, it would transform into a larval tapeworm and that’s what is being transmitted to a human in this case. That would go to the intestine and grow into this giant worm.”

(On one of our first dates, over 12 years ago – same age as barfblog.com — Amy tried to serve me grilled salmon. I whipped out my trusty tip-sensitive digital thermometer and noted a 98F reading, and said, no way. Cook it.)

The tapeworm is a monstrous and impressive creation. It has a segmented body, with male and female reproductive organs in each segment, so it is capable of self-fertilisation. It does not have a head as such – its “head” is only useful for holding on to its host’s gut, rather than for “eating” (it absorbs nutrients through its skin). In many cases, you would not know you were infected. You might spot bits of tapeworm segment in your stool – small, pale, rice-like bits – or experience stomach pain or vomiting.

Food Safety Talk 143: I Don’t Want Dead Water

Don and Ben chat about Skype and the weather (as always) but do get eventually to food safety stuff including disco dust, diamond lattes, home chicken slaughter, E. coli O157:H7 in Romaine lettuce (or not, or maybe, yes), raw water and frozen biscuits.

Episode 143 can be found here and on iTunes.

Show notes so you can follow along at home:

 

Pop-up turkey thermometers can suck

I usually pull the pop-up thermometer out of my bird when I cook it. I’m a digital-tip-sensitive thermometer kind of guy. Last Thursday, while roasting this year’s turkey, I left mine in, as a bit of an experiment for my graduate student Minh, like last year’s Consumer Reports pop-up test:

We tested 21 pop-up thermometers in whole turkeys and turkey breasts. Our testing covered pop-up timers bought online and put into place by cooks before sliding the bird into the oven, and models pre-inserted in the meat at the processing plant. To determine the pop-ups’ accuracy, we also measured the internal temperature of the meat with a calibrated reference thermometer. Our findings may make a few eyebrows pop:

Self-inserted and manufacturer-inserted timers generally “popped” in our tests at internal temperatures above 165° F—the minimum safe temperature for all poultry. But three timers popped up when meat was still below that safe zone, one as low as 139.5° F.

Here’s mine (right, exactly as shown). Thanks pop-ups, I was only 20F (and 75 min of roasting) short.

 

Tell us about your turkey

This past year at IAFP 2017 a student of mine, Minh Duong gave a presentation on thermometer use in turkeys collected by citizen science – a project that came out of our collaboration with John Luchansky and Anna Porto-Fett at USDA ARS and Caitlin Warren, a high school science teacher in Souderton, PA.

What makes this method cool is that it allows for easy data collection where the participants are the ones collecting and interacting with it.

We’re doing some more stuff again this year, If you’re cooking turkey over the Thanksgiving holiday, please come and take this survey.

Same-sex marriage and thermometers promoted in Australia: Welcome to the naught years

Australian politicians decided to be good politicians, not leaders – because pioneers get arrows in their back – and threw the issue of same-sex marriage to a public mail-in vote. The yes side won by a 2:1 margin, thereby undermining the foundation of Western society (or so some say).

I say, who cares, let same sex people enjoy the benefits and grief of marriage like the rest of us.

Australian food safety week is Nov. 11-18, 2017.

The organizers have been to my church, and the theme is not hockey, but, “Is it done yet? Use a thermometer for great food, cooked safely every time.”

Stick it in.

The theme last year was“Raw and risky.”

Uh-huh.

These PR thingies are increasingly meaningless.

Chapman is coming over in Jan. or so, once our renovations are done.

Bring another batch of thermometers, buddy.

If a group wants to promote thermometer use, give them away.

According to a self-reported bullshit survey, 70% of Australians don’t know that 75°C is the safe cooking temperature for high-risk foods such as hamburgers, sausages and poultry. 75% of Australians surveyed also reported that there wasn’t a meat thermometer in their household and only 44% of those with a thermometer reported using is over the previous month.

Check out our media release Australians clueless about safe cooking temperatures – Use a thermometer for great food, cooked safely every time.

Stick it in and get it safe

Our contractor warned us the house would like a missile site for a few weeks.

It does, after Canadian daughter 4-of-4 and her boyfriend moved in.

Aussie time.

What I do notice is the builders are always shouting out measurement in millimeters.

120-this, 280-that.

So why wouldn’t anyone expect the same precision in cooking and use a tip-sensitive digital thermometer instead of some food porn adjectives.

We expect bridges to stay up when we cross them, house to stay intact when they are reinforced with steel.

We should expect food to be safe when we cook it.

That requires data, not porn.

Maybe not so slightly pink: Properly cooked pork chops may contain threat of Listeria and Salmonella for consumers

If you are eating leftover pork chops that have not been cooked well-done, you’re putting yourself at risk for Salmonella and Listeria exposure. While many individuals prefer to consume their pork medium, a new study published in Risk Analysis: An International Journal revealed that cooking pork chops to an acceptable temperature does not completely eliminate pathogens, providing these cells with the opportunity to multiply during storage and harm consumers.  

The study, “Impact of cooking procedures and storage practices at home on consumer exposure to Listeria monocytogenes and Salmonella due to the consumption of pork meat,” found that only pork loin chops cooked well-done in a static oven (the researchers also tested cooking on a gas stove top) completely eliminated the Listeria and Salmonella pathogens. Other levels of cooking, i.e. rare and medium, while satisfying the requirements of the product temperature being greater than or equal to 73.6 degrees Celsius and decreasing the pathogen levels, did leave behind a few surviving cells which were then given the opportunity to multiply during food storage before being consumed.  

It is generally believed that when meat is heat treated to 70 degrees Celsius for two minutes, a one million cell reduction of E. coli, Salmonella, and Listeria is achieved and thus the meat is free of pathogens and safe to eat. However, a report by the European Food Safety Authority revealed that more than 57 percent of Salmonella outbreaks in 2014 were in the household/kitchen, and 13 percent were associated with inadequate heat treatment. 

“The results of this study can be combined with dose response models and included in guidelines for consumers on practices to be followed to manage cooking of pork meat at home,” says Alessandra De Cesare, PhD, lead author and professor at the University of Bologna.  

In order to assess the pathogen levels in cooked pork, the researchers, from the University of Bologna, the Institute of Food Engineering for Development and the Istituto Zooprofilattico delle Venezie, tested 160 packs of loin chop. The samples were experimentally contaminated with 10 million cells of L. monocytogenes and Salmonella to assess the reduction in pathogens after cooking, in accordance with the Food Safety and Inspection Service (FSIS) and British Retail Consortium (BRC) specifications (ensuring a reduction of at least 100,000 and 1,000,000 cells, respectively). The samples were contaminated on the surface, to mimic contamination via slaughter and cutting.  

The samples were divided into groups to be cooked either on gas with a non-stick pan or in a static oven. In each setting, the pork chops were cooked to rare, medium, and well-done. For each cooking combination, 40 repetitions were performed for a total of 240 cooking tests.  

The researchers also interviewed 40 individuals between the ages of 20 and 60 to determine household consumer habits regarding doneness preferences. Prior published research was referenced to define meat storage practices and the probability that consumers store their leftovers at room temperature, in the refrigerator or discard them immediately. Growth rate data for the pathogens at each temperature were obtained using the software tool ComBase.  

The only cooking treatment able to completely inactivate the pathogens was oven well-done, which achieved a reduction between one and 10 million cells. Statistical analyses of the data showed significant differences related to level of cooking and cooking procedure. However, the researchers explained that factors such as moisture, water activity, fat levels, salts, carbohydrates, pH, and proteins can impact the cooking treatment and effectiveness and, as a consequence, on bacteria survival. These results emphasize the needs to consider the form of pork (such as whole muscle versus ground) being cooked, in addition to the final temperature necessary to inactivate pathogens.  

The results show that a reduction between one and 10 million of pathogen cells was reached when applying all of the tested cooking treatments, with product temperatures always reaching 73.6 degrees Celsius or greater. However, according to the simulation results using the obtained cell growth rates, the few surviving cells can multiply during storage in both the refrigerator and at room temperature, reaching concentrations dangerous for both vulnerable and regular consumers.  

After storing leftovers, there was a probability for the concentration of pathogens to reach 10 cells ranging between 0.031 and 0.059 for all combinations except oven well-done. Overall, the mean level of exposure to Listeria and Salmonella at the time of consumption was one cell for each gram of meat. The results obtained from this study can be implemented in guidelines for consumers on practices to follow in order to manage cooking pork meat at home.