Just as wheat is the staff of life in many human civilizations, it is as important to animals and insects. In fact, they love it, as anyone who has lived near or worked in the wheat fields very well knows. All manner of critters, including deer, birds and rodents will seize the opportunity to dine on wheat whether it be growing in the fields or temporarily stored in huge piles on the ground after harvest.
A deer makes its way through a wheat field on the Palouse region in southeast Washington. More land is planted with wheat in the world than any other crop. It provides 20 percent of the world’s caloric consumption, and 20 percent of the protein for half of the world’s poorest people. (Photo by Horst Onken)
And therein lies the problem — at least when it comes to food safety. Wildlife can carry E. coli, Salmonella, Listeria and other pathogens that can contaminate human foods via a variety of routes.
Leslie Smoot, a senior advisor in FDA’s Office of Food Safety, said it’s simply a matter of sharing the planet with other animals.
“Flour is derived from a grain that comes directly from the field and typically is not treated to kill bacteria. So if an animal heeds the call of nature in the field, bacteria from the animal waste could contaminate the grain, which is then harvested and milled into flour,” Smoot said.
Although people don’t usually associate flour with foodborne diseases, a multi-state E. coli outbreak linked to contaminated flour sold by industry giant General Mills Inc. has sickened at least 46 people, with 13 people needing to be hospitalized. One of them has a life-threatening kidney condition known as hemolytic-uremic syndrome (HUS).
The first confirmed E. coli case in the General Mills recall was reported on Dec., 21, 2015, with the most recent victim falling ill on June 25, 2016. The flour giant recalled 45 million tons of flour and other companies issued secondary recalls because they used the flour to product their foods.
The recall included three main brands of flour, Gold Medal, Signature Kitchens and Wondra. According to the Centers for Disease Control and Prevention the related recalled products ranged from bread and pancake mixes to meat and poultry products.
In addition to household consumers, General Mills also sells bulk flour to customers that use it to make other products. Some of those products, Marie Callender’s biscuit mix, Betty Crocker cake mix and Krusteaz pancake mix, also had to be recalled if they were made with flour in the recalled lots
Not the first time, or the last — the cookie dough connection
An E. coli-related flour recall in 2009 was triggered when raw, prepackaged Nestle cookie dough sickened 77 people. That happened when some of the people making the cookies nibbled on some of the raw cookie dough. In that outbreak, 35 people had to be hospitalized and 10 developed hemolytic-uremic syndrome.
That triggered Nestle to switch to heat-treated flour for its refrigerated cookie dough.
“That’s the only way you can get rid of the microbes in a wheat flour,” Sunil Maheshwari, vice president of Siemer Specialty Ingredients, told a USA Today reporter, referring to heat treatment. He also said that heat-treated flour is what makes cookie dough found in ice cream or candy safe to eat.
Cookie dough and pathogens hit the headlines again this week with the recall of two flavors of Blue Bell Creameries’ cookie dough ice cream because of Listeria concerns. The cookie dough from third-party supplier Aspen Hills Inc. was recalled because of possible Listeria contamination, according to Blue Bell’s recall notice.
However, John Austin, a spokesman for the Iowa-based Aspen Hills said the flour in the cookie dough had been heat-treated.
“Our testing didn’t find any Listeria,” he said.
Why not heat-treat all flour?
Don Trouba, marketing director for another mega-flour producer, Ardent Mills LLC, discussed flour-related microbiological risks in a special webinar earlier this month.
The Denver company hosted the online session to provide a step-by-step look at the milling process, as well as possible grain- and flour-related microbiological risks, beginning in the wheat field and ending in the grocery store baking aisle.
Ardent Mills developed a special flour, dubbed “Safeguard,” which has been treated using a “proprietary, all-natural process” to get rid of bacteria. The company says the process doesn’t harm the taste, color, appearance or “gluten functionality” of the flour. And because of its versatility it can be used for refrigerated biscuit and cookie dough, pizza crusts, frozen doughs, cereals, and retail packaged flour. It’s primarily used by commercial customers.
As for irradiating the flour to kill the pathogens, industry officials say that option wouldn’t be acceptable to consumers, despite the effectiveness of the procedure.
A combine at full throttle at harvest time near Tri-Cities in southeast Washington state. (Photo by Horst Onken)
Out in the field
Wheat fields often extend for miles and miles. People driving by them don’t actually see the individual wheat plants, which before producing tiny kernels, actually have tiny flowers. Instead, people see a broad swath of color — green when the wheat is young and golden yellow when it’s getting ready to be harvested.
Many people don’t equate the flour they use to make breads, cakes, muffins and tortillas with the wheat fields they may have driven past.
That’s why Ardent Mills officials wanted to provide a glimpse of the process, as well as to explain some of the food safety realities that go with it.
Kent Juliot, Ardent Mills vice president of research, quality and technical solutions, said during the webinar that in addition to wheat being subject to possible incursions from animals and birds, the previous use of crop land is part of the food-safety equation.
Even so, contamination rates are extremely low, he said.
Milling the wheat
When the wheat is taken to a mill, it is cleaned, milled and then sifted. The goal, of course, is to remove the outer layer of the wheat kernel and grind the interior endosperm into flour.
The three parts of a wheat kernel are the bran, the germ and the endosperm. (Illustration courtesy of the Kansas Wheat Commission)
As for the cleaning of the wheat, itself, Ronald Burke, Ardent Mills senior director of food safety and quality, said the process involves removing unwanted objects, such as stones, pieces of metal, and kernels with color differences. It is, however, not designed to remove foodborne pathogens such as E. coli and Salmonella.
In fact, nowhere in the milling process does that happen, although food safety standards are followed when it comes to keeping equipment and trucks clean, training employees, abiding by good manufacturing practices, and conducting an analysis of possible contamination points in the process.
Bottomline, milling is a simple, mechanical process, Burke said. It doesn’t address microbial pathogens.
Even though the CDC warns the public that flour is actually a raw, uncooked food, most people don’t see it that way.
Flour, especially white flour, doesn’t look raw. It looks processed. And the very process of milling wheat into flour can spread contamination from a few wheat kernels to large quantities of flour.
Even so, it’s extremely rare for people to become ill from eating flour for one simple reason: Flour is rarely eaten raw. Instead it’s added to other ingredients and baked, fried, boiled or microwaved, which generally kills pathogens. But with raw dough, there is no kill step.
Yet it’s not uncommon for people making cookies, pie crusts and cakes to nibble on some of the dough or to let their children lick the bowl where cake batter was mixed. And some people actually eat defrosted frozen pizzas without cooking them first.
With that in mind, General Mills has repeatedly warned the public since its recalls: Do not eat uncooked dough or batter made with raw flour. Flour is made from wheat that is grown outdoors where bacteria are often present. Flour is typically not treated to kill bacteria during the normal milling process.
Warning labels considered
The General Mills recall and related outbreak has generated some discussion about how best to remind people to never eat raw flour and to always wash their hands with soap and water after handling raw flour, dough or batter.
During the Ardent Mills webinar, Juliot said that this is a topic of great interest to the industry. “We expect warning statements to become more prevalent,” he said, conceding that there’s still room for improvement.
The label on this Pillsbury pie crust box includes a warning not to eat raw pie crust dough. (Photo by Cookson Beecher)
Melissa Kirkwood, spokesperson for AIB International, formerly known as the American Institute of Baking, said warnings are “on the forefront of industry concerns.”
Stephanie Lopez of Food Safety Services at AIB International in the Americas said there are no requirements for products to be labeled with warning statements for not-ready-to eat (NRTE) foods. However, food manufacturers are required to communicate to their customers and consumers any safe handling requirements, such as refrigeration and cooking instructions.
“It’s more about telling the consumer what to do, rather than what not to do,” Lopez said.
Some products already have warning labels. Pillsbury’s refrigerated pie crust contains this statement: DO NOT EAT RAW PIECRUST.
However, tubes of Western Family’s naturally flavored refrigerated cinnamon rolls with icing carry no such label, although in bold letters at the end of the list of ingredients, it does warn that the product contains wheat, eggs and soy.
And not all products, such as fried fish that looks like it’s ready to eat because the flour-crust on it has been browned, carry that sort of warning.
In the end, it’s the consumer’s responsibility to make sure raw dough and flour in any form isn’t eaten. And that, of course, calls for more consumer education.
In a white paper — “Flour Food Safety” — written for Ardent Mills by author Deann Akins, two prevailing misconceptions are put to rest.
MYTH: Pathogens such as Salmonella are not of importance to low-moisture ingredients such as flour simply because these ingredients do not support its growth.
FACT: Salmonella does not need to grow to cause illness. In some instances infection has occurred from consuming low-moisture products contaminated with less that 1 cfu/g. It’s also important, says Akins, to note that flour may be added to ingredients such as batters and mixes that are more conducive to growth.
MYTH: Sample testing is a reliable way to assure food safety.
FACT: Microbiological testing of a production lot of a food product does not guarantee that the entire lot is pathogen free. Production lots of flour are usually very large, so only a fraction of a lot can be tested. Pathogens generally are not homogeneously distributed throughout the lot; they tend to clump together in groups.
This means that a sample tested for a pathogen can test negative when other areas in the same lot may contain pathogens. Considering how much testing would be needed, said Akins, “testing to this magnitude is not realistic because it’s cost prohibitive.”
Martin Wiedmann, Gellert Family Professor of Food Safety at Cornell University. (Photo by Cookson Beecher)
Martin Wiedmann, a food safety professor at Cornell University, warns that companies cannot rely on the consumer to play it safe. Instead, they must understand what the consumer can do and will do with their products.
“Every company has to think this through,” he said.
Another question posed by Wiedmann: “Is the risk so low that the risk to the consumer is low? Because you’ll never make food 100 percent safe. The challenge is where do you strike that balance?”
He said he’s seen companies make food safe to eat but in some cases it just doesn’t taste good. And while you can make flour safer, the risk you run is that it will lose some of its “behaviors,” such as the adequate rising of bread.
The other option is not to have a product.
“That’s the conundrum of food safety,” Wiedmann said. “It’s like life. If playing sports can be dangerous, does that mean we should sit on the couch and watch TV instead?”
And he predicts that “it’s going to get worse before it gets better.”
“Consumers’ expectations are higher now,” he said. “They want food to be safe but they also want it to taste good, be affordable, be convenient, and have a low environmental impact. The challenge before us is ‘How do we help people make informed decisions?’ ”
Advice for consumers
FDA offers these tips for safe food handling of flour.
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