Different flours bake differently
August 1, 2013
by Laurie Gorton, Baking & Snack
Putting variety flours to work in the bakery takes a bit of extra care in handling and more substantial changes in formulation and processing.
These ingredients should be held in a cool, dry location, preferably at less than 75°F and under 50% relative humidity, and kept away from spices and other food ingredients with strong odors, advised Beth Arndt, PhD, director of R&D, ConAgra Mills, Omaha, NE.
Corn flour’s shelf life in inventory is about the same as whole wheat flour, according to Jeff Casper, R&D manager, Horizon Milling, Wayzata, MN. “How you handle whole wheat flour should also suffice for Cargill’s Maizewise whole grain corn flour,” he said.
The bran and germ present in most nonwheat flours pose other storage problems. Nonstabilized flours will need protection against oxidative rancidity. Bryan Scherer, director of R&D, Penford Food Ingredient Co., Centennial, CO, recommended antioxidants such as rosemary extract or tocopherols be included in product formulations.
Formats include single or blended grains; whole, flaked, puffed and toasted forms; and a full range of flour granulations. In doughs based on wheat flours, nonwheat grain blends can be used at 10 to 20%, flour weight basis, according to Mr. Casper. “The other half of the story are grain blends used to top or enrobe pan bread doughs,” he added, suggesting a topping rate of 2%.
“You can get different textural effects with the range of granulations,” Mr. Casper said. “Some like the grit in a muffin. For pan bread, however, a finer grind is recommended. To achieve various visual effects, the baker can use a blend.”
The question of structure
Formulators must account for functional differences, which include changes in texture, absorption and strength. “Balancing the granulation of the whole grain, the amount of water required and added time to allow for proper absorption are all ways to resolve changes in the finished product texture,” explained Brook Carson, director of R&D, ADM Milling, Overland Park, KS.
“When nonwheat or whole grain is introduced into the baked products, gluten strength is diminished,” she continued. “Adding wheat proteins such as wheat protein isolate can improve sheeting and dough handling as well as finished product quality.”
Bran and germ in a whole-grain flour, wheat or nonwheat, provide no support to dough structure and actually disrupt the gluten network. This makes air entrapment more difficult and affects the crumb texture of the finished product. They also affect water balance.
“Bran and germ take on more water during mixing but lose water more quickly in the final product, possibly resulting in shorter shelf life,” Ms. Carson explained.
A good piece of advice is to treat nonwheat flour as an entirely different ingredient, not a flour. “In general, any new ingredient will change the dough, and consumers will notice differences in the finished product,” said Susan Kay, manager, product applications, Bay State Milling Co., Quincy, MA.
“It’s important to know the grain’s water-holding capacity,” she continued. “Some hold a lot, and some don’t hold much water at all.” She recently tested the absorption of various ancient grains and found high rates for amaranth and spelt, moderate for teff and quinoa, and poor for millet and sorghum. Grains with higher absorption will require baking at lower temperatures and for longer times, she advised.
Although rye, barley and oats contain gluten, it’s not the same as wheat’s and won’t perform the same structural role. To compensate, bakers should add vital wheat gluten when working with nonwheat flours in all but gluten-free applications. This adjustment, however, will increase water requirements. “The rate of hydration will change, and you will see differences in the rheology of the batters and doughs,” Mr. Casper advised.
Water control essential
Hydration requirements can change the process in other ways. “Some grain ingredients may require prehydration or more time to hydrate,” Dr. Arndt said. “A common problem in making whole-grain and multigrain doughs is the addition of too little water. It is also critical to not under- or over-mix dough because whole grain and multigrain doughs generally require less mixing time compared with refined wheat flour doughs.”
Flour-like ingredients for gluten-free foods — for example, Penford’s PenTech GF line — include structural components such as food starches and hydrocolloids that mimic the functionality of gluten. “Another factor to consider is that nonwheat dough often produces a looser texture than wheat dough,” Mr. Scherer said. “This requires special handling when forming into loaves or other shapes.”
Some baked foods require less work. Patrick O’Brien, bakery marketing manager, Ingredion Inc., Westchester, IL, reported, “As an example, Ingredion’s Hi-Maize whole grain corn flour is easy to formulate into most low-moisture foods without affecting mixing or cooking.” The company maintains a library of starting formulations for many different applications to help cut down on product development or reformulation time.
And then there’s the matter of flavor. Some nonwheat flours have more pronounced effects than others. “The flavor difference is typically due to the additional tannins found in the bran of the grain,” Ms. Carson observed. “Whiter whole-grain varieties typically contain fewer tannins, which results in a less bitter taste.” She recommended use of more sweetener or a masking agent to overcome such taste problems.
Pulse flours made from edible beans, legumes and lentils are seen as an interesting way to add health appeal to baked foods and snacks. Experiments at the Canadian International Grains Institute reveal tremendous potential, according to Heather Maskus, MSc, project manager, pulse flour milling and food applications, Canadian International Grains Institute (CIGI), Winnipeg, MB. Because they are different from regular flour, they will require some modification in processing and formulation approaches.
“Typically, the pulse flours have higher water absorption capacity compared with wheat flour,” she said. “However, in optimized formulations, using less water typically helps with machinability and handling when working with pulse flour ingredients.”