Tongue-testing dangerous: microwaves that heat unevenly can pose food safety problems

I expect companies like ConAgra and government agencies like the department of agriculture to blame consumers when their 50 cent pot pies make hundreds of people barf – just follow the instructions.

I don’t expect Consumer Reports to blame the consumer when microwave cooking makes people sick. But I have low expectations, especially of so-called consumer groups.

Consumer Reports latest tests of microwaves found fewer models that aced our evenness test.

When food isn’t cooked evenly to an internal temperature that kills harmful bacteria that might be present, illness can result, according to the USDA. So using a microwave that delivers even heating is important.

You’ll need to cook food longer if your microwave’s wattage is lower than the cooking instructions requires. Our Ratings indicate wattage, and you’ll find it on the serial number plate on the back of the microwave, inside the microwave door, or in the owner’s manual.

The USDA also recommends using a food thermometer to test food in several spots, but the survey found most people don’t, and nearly a third said nothing would change their mind. Using a food thermometer is a good idea, but at the very least, make sure there are no cold spots in your food.

How? With your tongue? Frozen foods that are going to be cooked in the microwave should contain pre-cooked ingredients.

Bon Appetit and simplistic food safety

Bon Appetit is a food porn magazine meant to titillate (it’s even in it’s name) and stimulate rather than inform, like most of what passes for food journalism.

This month, the so-called Conscious Cook has a brief piece, 5 Reasons You Shouldn’t Hate On Microwaves.

Hate is a strong word. I like my microwave, especially for reheating, not cooking.

The author maintains that microwave defrosting reduces the risk of foodborne illness and that “defrosting frozen food by using hot water or leaving it in the sink can increase bad bacteria. To defrost fast, microwave food on low heat, then cook immediately. Stir contents halfway through heating for even warming.”

I cook a whole chicken about once a week. It’s inexpensive, and provides leftovers and stock for subsequent meals. If I’m defrosting a whole chicken in a microwave, I’m not going to stir it “halfway through heating for even warming.”

The U.S. Department of Agriculture and Health Canada recommend thawing poultry by sealing in a waterproof bag and immersing in cold water. These same groups also used to recommend washing chicken bits, but decided the microbiological splash fest created by running water over raw poultry was a bad idea. To me, immersing in cold water and changing that water every 30 minutes is an additional route to microbial cross-contamination. The Aussies and the Brits agree, and do not recommend water immersion.

Depending on my planning, I use a combination of the counter and the refrigerator for thawing the bird. American and Canadian science-types say this is awful, and I’ll make everyone barf. The Aussies and Brits say counter-top thawing is fine, as long as it’s monitored – a week may be too long.

We have previously reviewed various thawing techniques and government recommendations. Whatever technique is used, be the bug, thinking in terms of cross contamination and growth, and use a damn thermometer to ensure the food has reached a safe internal temperature. Color is a lousy indicator and piping hot is just weird (so is Canada’s Mrs. Cookwell).

Fewer food violations in school cafeterias

Cafeteria food inspections tend to have fewer critical violations than let’s say your full scale service restaurant due to minimal food preparation involved. Everything is essentially pre-packaged and heated in a microwave prior to service or deep fried for the non health-conscience consumer. As such, cafeteria food operators need to pay attention to effective hand washing as well as verifying internal cooking temperatures of what actually goes in the microwave. Food products that are generally cooked in the microwave are initially frozen and thus may not achieve the desired temperature that will inactivate food borne pathogens and keep you from barfing.
I thought this article was interesting as I just returned from the Twin Cities from a fantastic concert (Jonsi).
The Duluth News Tribune reports
Inspections of school cafeterias turn up far fewer problems than inspections of restaurants and convenience stores, say the people who probe the pantries, refrigerators and sinks of local schools.
Government inspection reports of several area school districts for the past three years showed only a few incidents that would make you say: “Ewww.”
Reasons for violations include: expired freshness dates for products, dented cans, rotten vegetables, a lack of hand-washing or glove changes between tasks, thawing and refreezing pizza, water not hot enough and milk not cold enough.
“Typically, schools are pretty good inspections for us,” said Brian Becker, an environmental health specialist with the Douglas County Department of Health and Human Services. “They are well-trained, maintained; they’ve had their staff for a while. Oftentimes in other industries in food, you’ll see a higher turnover.”
School cafeterias must be inspected twice a year. Most schools this year had low numbers of critical violations — those that can lead directly to food-borne illnesses — or none at all. Non-critical violations — of which there were higher numbers — don’t directly cause illness; they often relate to equipment or flooring. But even they can lead to food-borne illness.
Improper hand-washing is the practice most potentially harmful to the health of students in cafeterias, said Ryan Trenberth, supervisor of the Duluth District Office of the Minnesota Department of Health, which has taken over for St. Louis County inspections.
“We’re finding that’s how most viruses get spread,” he said. “Sick employees … not hand-washing, or cross-contamination going from a raw product to a ready-to-eat product.”
Neither inspector could remember any food-borne illnesses spread in school cafeterias in Douglas or St. Louis counties.

Gratuitous food porn shot of the day – Steamfresh corn on the cob

Sorenne eating lunch with dad, 11:00 a.m., Nov. 18, 2009.

Kids love corn on the cob. Me too. Bit it’s difficult to find in mid-November. In Manhattan (Kansas). SO I tried out the Steamfresh frozen corn on the cob. Microwave and serve. Yummy. Expensive, but a cob of corn gives me 15 minutes to put stuff away and clean up. Better than the sucker (her first) she had after making a deposit at the bank.

Watch where you’re sticking it in

I’ve loved Chicken with Broccoli and Cheese (of various brands) since childhood. These prepared-but-raw entrees mostly fell by the wayside when I started cooking like a grown-up. But just last week, the crunchy broccoli with melted cheese hidden inside tasty breaded chicken thingies called out to me and my inner child, and a box of them was soon in my home freezer.

A couple years ago (under the alias C. Wilkinson), I watched a bunch of people cooking products just like these in model kitchens. I was helping graduate researcher Sarah DeDonder, who was curious what could be contributing to the half-dozen Salmonella outbreaks associated with such products that occurred in the ten years before the study (and the two outbreaks after).

The raw, frozen chicken thingies I brought home last week were made by Antioch Farms (a Koch Foods brand). The box’s front label proclaimed, in half-inch-high letters, that the products were indeed raw. The back label warned me not to cook them in the microwave. It also showed me how to stick a thermometer in to be sure each one reached a bacteria- and virus-killing 165 F.

I found each of these label features fairly helpful. However, when I baked them for dinner last night, I modified the depicted thermometer-sticking method a little to determine the internal temperature of the chicken, rather than the filling.

I’m happy to report that the chicken read 175 F before it reached the dinner table. And it was as delicious as I remembered.

Microwaving listeria out of potatoes

Minnesota-based food maker Northern Star is recalling several different refrigerated potato products after some samples were found to have Listeria monocytogenes.

According to WCCO-TV, a former employee had already reported concerns about listeria on plant equipment to the FDA.

I’m not sure what his role was in the company, but he told the news crew,

“…I like to protect the people who eat this product. I’ve seen mice all over the place. Cockroaches, black mold, listeria: I mean you name it, you can find it."

Sounds pretty gross, but—if necessary—most of the poop can be cooked out of food.

A report of the recall by noted,

“Officials say properly cooking the food kills Listeria bacteria, but the Minnesota Department of Agriculture says often times people overlook the cooking instructions and simply heat these products in the microwave.”

It only takes a couple minutes to kill listeria if you can get the food up to 158F. A microwave can do this quickly, but unevenly. The cold spots that don’t get up to the right temp can still have listeria bacteria living in them.

Therefore, many manufacturers—such as Northern Star—don’t provide that option in the cooking instructions.

However, pretending people don’t use the microwave is not a realistic way to minimize the risk of someone getting sick.

Some have suggested acknowledging consumer use of microwave ovens by pasting DO NOT MICROWAVE on packages of foods that are likely to make people sick if they’re not cooked properly (like raw chicken thingies).

In the case of refrigerated hashbrowns, it’s probably reasonable to provide instructions for the microwave and include a little note on the dangers of uneven cooking.

This would give consumers the opportunity to make an informed decision on how they’ll cook their potatoes. Particularly when there’s poop in them.

So far, no illnesses have been reported in connection with this recall. Providing more information to consumers could help ensure that’s the case.


Food safety quick hits

KETV in Omaha is reporting that Girl Scout cookies are safe to eat — the peanut butter products that are used to make them are not produced by Peanut Corp of America:

The peanut butter supplier associated with the recent salmonella outbreak does not supply peanut butter to Girl Scout Cookies, according to the Girl Scouts organization.

The Girl Scout organization’s supplier is Hampton Farms in North Carolina.

In the somewhat-related-to-food-safety category, a man who helped create the science behind the microwave oven has died. Robert Decareau of Amherst, NH passed away on Sunday at 82.

According to his family, Decareau was a Massachusetts native who went to work for Raytheon after earning his doctorate in chemistry. It was there that he started working on microwave energy food applications, and he was one of the first to call himself a food scientist.

Decareau’s daughter, Karen Ross of Auburn, Maine, says she remembers her father experimenting with a refrigerator-sized prototype microwave oven in the family’s basement in the 1960s.

Frozen, raw or partially cooked foods have been problematic for consumers — especially when they contain pathogens.  There have been at least eight outbreaks linked to, as Doug likes to call them, chicken thingies since 1998.  Using a microwave has been reported as a factor in these outbreaks. Pot pies have also been linked to microwave problems. Uneven heat distribution makes microwaving a not-so-good method to cook raw foods especially if digital tip-sensitive thermometers aren’t used.  Sarah DeDonder presented some of our research at IAFP last year on microwave cooking practices in a model kitchen. A paper on the research will be published later this year.

Dedonder, S., Powell, D.A., Jacob, C., Surgeoner, B., Chapman, B., and Phebus, R. 2008. Beyond Intent — Direct Observation Of Meal Preparation Procedures In A Home Kitchen Setting.


Purpose – This study used a novel video capture system to observe the food preparation practices of 41 consumers – 21 primary meal preparers and 20 adolescents – in a mock domestic kitchen using uncooked, frozen, breaded chicken products, and to determine if differences exist between consumers’ reported safe food handling practices and actual food handling behavior as prescribed on current product labels.

Design/methodology/approach – A convenience sample was utilized and all participants were video-recorded preparing food in one-of-two model kitchens at Kansas State University. Participants were asked to complete a survey reporting food handling behaviors that would be typical of their own home kitchen.

Findings – Differences between self-reported and observed food safety behaviors were seen across both groups of consumers. Many participants reported owning a food thermometer (73 per cent) and indicated using one when cooking raw, breaded chicken entrées (19.5 per cent); however, only five participants were observed measuring the final internal temperature with a food thermometer despite instructions on the product packaging to do so; only three used the thermometer correctly.

Significance – Data collected through direct observation more accurately reflects consumer food handling behaviors than data collected through self-reported surveys, and label instructions are rarely followed.

Originality/value – This study contributes to the overall understanding of consumer behaviors associated with consumers’ intentions and actual behaviors while preparing meat and poultry products, such as frozen, uncooked, breaded chicken products.

How can you be sure microwaved frozen chicken is safe to eat?

Judy Foreman of The Boston Globe says the U.S. Department of Agriculture recommends no matter how frozen chicken is cooked, from whatever kind of meal or chicken thingies, use a thermometer to ensure the internal temperature has reached 165 degrees Fahrenheit.

Good advice.

So why at the end of the brief article is Roger Fielding, a professor of nutrition at Tufts University, quoted as saying, "Always cut it open and make sure it is white, not pink or translucent. You really have to be careful."

Bad advice.

What you really have to be careful about is taking food safety advice from nutrition professors at Tufts University.

Color is a lousy indicator. Use a digital, tip-sensitive thermometer.

Cooking with a microwave

In October 2007, at least 270 people in 36 American states got sick with Salmonella after eating Banquet Pot Pies, leading to a national recall and prompting many to question the safety of microwave cooking. Since the outbreak, the manufacturer, ConAgra, has revamped their labeling to try to ensure proper microwave preparation by consumers.  But questions still loom whether these label changes are enough, and may leave people wondering how to properly cook using a microwave.

For thick items that can’t be cut:
∑ use medium power;
∑ microwave for a longer period of time;
∑ stir, turn, or flip food halfway through to limit cold spots;
∑ let food stand for a couple minutes when finished microwaving; and,
∑ be cautious of bones (they can act as heat shields.

There are many other variables that dictate how well food is cooked in the microwave, including:
∑ type of container;
∑ physical state of food (frozen or thawed);
∑ type of food;
∑ product geometry;
∑ moisture content;
∑ bone presence; and,
∑ microwave wattage.

The wattage of a microwave is located on the back or inside the door.  Microwave power is grouped into high (1000 – 1300 W), medium (700-900 W) and low (500-600 W).  Many labels on microwave foods give cook times for high, medium and low wattage microwaves, so it is handy to know the wattage being used.

There are hundreds of frozen, prepared products or meals, like pot pies, that may contain raw or fully cooked ingredients. The only way to know is to read labels carefully. Package labels may also contain instructions to cook to 165°F for poultry and 160°F for beef and other meats, and to verify doneness using a digital, tip-sensitive thermometer.  To be on the safe side, leftovers should reach 145°F.