Science Seeks Better-Bred Bread
Government geneticist goes after culprit
gumming up big bakeries’ dough works
BY ED MURRIETA
ALBANY, Calif. — The eastern shore of San Francisco Bay hardly inspires images of amber waves of grain. But it’s right here in Albany, a dozen traffic-choked freeway lanes away from a horse-racing track on the water’s edge, where a U.S. government plant geneticist may change the nature of wheat plants and commercial bread production.
Ann Blechl works for the Agricultural Research Service, a division of the United States Department of Agriculture, whose tax-payer funded mission is to find solutions to agriculture problems that affect Americans from the field to the table.
A team led by Blechl is trying to solve a problem that affects large-scale commercial bakeries: how to control the stickiness of bread dough made from certain wheat flour. The conundrum is ironic: Overstickiness may have cropped up as a result of a “breakthrough” 20 years ago, when researchers cross-bred rye with wheat in order to obtain a more hardy wheat plant. Now it may take genetic engineering to isolate and remove the rye gene that is suspected of causing wheat flour to produce sticky dough.
“I’ve had a long-time interest in the proteins in wheat flour that control strength,” says Blechl, who, despite her government-drab surroundings, becomes schoolgirl-giddy when talking about things like gluten, glutenins and gliadins. “Wheat is absolutely unique. It’s the only food that has these very special proteins that allow you to develop elastic that will hold their shape and flow so you can make a gas bubble inside dough.”
Not a boondoggle
If this sounds like another one of the government’s $500 toilet seats, consider that large commercial bakeries — the Wonders and Oroweats of the world — depend on automated systems to mix and shape a ton of dough at a time. Anything that gums up the works — big bakeries call them “stick-ups” — can be costly.
“We are a business that works off economies of scale,” says Robert Hardy, the operations manager for Wonder and Hostess bakeries in Northern California “We have to make bread at 200 units a minute to become profitable. It’s not like stick-ups happen 10 times a day or every hour. All I can say is, the speed at which we run, when you have a stick-up, it creates a problem.”
In response to the American Bakers Association, a trade group that identified sticky dough as a persistent problem during an annual meeting with the Agricultural Research Service, Blechl and her team are working to genetically transform some of the pest- and weather-resistant varieties of wheat that Midwestern farmers prize for their high yields. “Breeders and farmers like these wheats because they’re hardier,” Blechl says. “The baking industry as a whole does not like these wheats because they’re stickier.”
Through traditional cross-breeding, several wheats have been produced that contain a piece of a chromosome of rye, a different but related cereal that by itself does not make good bread. What Blechl hopes to accomplish
— and where controversy begins — is to identify various rye genes in these wheats and to genetically modify whatever it is that produces a protein which contributes to the stickiness of dough. If successful, the “transgene” will be introduced into wheat by regular cross-breeding.
“Given that the farmers are going to continue to grow this wheat with the rye, we would like to know what is the factor that makes bread dough sticky,” Blechl says. “We’re taking genes that code for rye proteins and putting them into wheat. The results hopefully will be wheat that doesn’t make this rye protein. It will have the rye genes, but the protein that would end up in the flour isn’t made. By doing this and selecting which genes we’re going to ‘turn off,’ we can determine what makes dough sticky.”
Catch culprit in the rye
It’s a detailed process that involves modifying individual genes and growing individual plants in a greenhouse based on each genetic transformation. If a new plant’s seed produces dough with changes in seed proteins and reduced stickiness in small-scale lab tests, that plant will be grown in highly regulated field trials. When a test crop produces sufficient grain for commercial-scale tests, it will be milled into flour, dough will be made and baking tests will be performed.
Blechl estimates the research should take five to eight years to complete. “We don’t even know all the genes that are in there because wheat hasn’t been sequenced,” Blechl says. “We have suspects that we have already isolated the genes for. Those are storage proteins of rye which are the equivalent of gliadins (proteins found in gluten) in wheat. We suspect it might be them. If our hypothesis is wrong, and it’s actually the absence of wheat rather than the presence of rye, then we can correct for the deficiency by introducing genes from wheat.” It’s like trying to find a needle in a wheat stack.
“As a percentage of all the genes, it’s about 1/100th of all the genes that have been swapped for rye,” Blechl says. “All we know is that the stickiness correlates with the presence of that piece of rye chromosome.” Stickiness is a natural quality of bread dough. Bakers want a certain amount of tacky resistance as dough is slapped around the mixing bowl or kneaded on the bench. But too much stickiness can ruin the dough.
“Stickiness is usually generated by two things: either too much water or heat build-up in the dough,” says Wonder Bread’s Hardy. “When you deal with whole-grain flour, it damages (the gluten) and the dough’s not allowed to absorb as much water and that results in the dough being sticky.”
The artisans weigh in
There is a contingent of bakers who do not embrace Blechl’s research, including Steve Sullivan, CEO of Acme Bread Co. in Berkeley. “Certainly, if you make your dough incorrectly or if you ferment your dough too much, you have to deal with consequences that may involve stickiness being more of a problem than a simple characteristic,” he says. “Stickiness is pretty much something we take for granted and work with. For us — as a small operator using organic wheat — we don’t want any genetically modified wheat to be in the ground at all, because it basically threatens our ability to produce something we feel good about. People who pump dough through a tube may have a real interest in this, but it may not be for artisanal breadmakers.”
Daniel Weggenman, a grain buyer and vice president of operations at Giusto’s, a South San Francisco miller of organic wheat, says Blechl’s research could have positive impacts on some sectors of the baking industry. After all, a consistent product that performs the same no matter who or what is doing the mixing is every bakery’s holy grail.
“With organic wheat, you’ve got a lot more variables — you’ve got to deal with the conditions you’ve been given,” Weggenman says. “Whether you get a lot of rain or drought conditions determines whether you get high-bushel yields with no protein or low-bushel yields with high protein. It’s actually a struggle.
“Wheat is a living plant, so it doesn’t always do things the same way. Dough is not living, because it can’t make more of itself, but it’s a dynamic thing. A very good baker could make a great loaf of bread out of just about any flour. They have the feel for when it’s fully developed. But we’re talking about mixing one ton of dough with machinery — that doesn’t have the feel. So the industry needs a very consistent product.”
While there are no genetically modified wheat crops in commercial production and opposition to genetically modified crops runs strong in some quarters, the benefits of Blechl’s research could still be put into effect the old-fashioned way:
“Natural preparations of any missing wheat proteins could be added to flours before mixing,” Blechl says. “Or traditional breeders could use the knowledge of which protein or proteins confer stickiness to select against the presence of ‘stickiness genes’ in the wheats they develop.” In practice, however, the former could be too expensive and the latter could take many years. “Maybe the plants we make don’t go beyond the lab,” says Blechl, whose greenhouse was vandalized during an earlier genetic modification project. “But the knowledge — that has to go out.”
The Western Regional Research Center, where Blechl operates, is among four such facilities operated by the USDA. Over the past 50 years, the lab’s researchers have improved frozen food storage; made powdered eggs taste better; invented the most widely planted breed of iceberg lettuce; and identified the natural yeast culture that gives San Francisco sourdough bread its distinctive quality.
“For me to be successful,” Blechl says, “I don’t need to make a marketable product. To the extent that either I or other people can apply that knowledge when I publish my findings, that’s what I’m trying to get out to the world.”