It’s the old conundrum. We know what and how much we should eat, but it’s hard to do it. Fiber sits high on that to-do list. Because whole grains are a naturally excellent source of fiber, food developers have an opportunity to help consumers meet a trifecta of dietary goals: increased fiber and whole-grains intake, as well as possible weight-reduction.
A fiber primer
The amount and type of fiber present in a whole grain is dependent on the type of grain. When grains are refined, the fiber present in the hull and the bran is literally stripped away. To increase the fiber content of foods, it’s important to use either whole-grain or bran ingredients.
Fiber is differentiated into two categories. Insoluble fiber sweeps material through the digestive system. Soluble fiber forms a gel-like material in water and helps regulate cholesterol and glucose levels.
Some grains, such as oats and barley, are known for their soluble fiber, specifically beta-glucan. Barley has 10% to 12% total fiber and 4% to 6% beta-glucan. Oats have 10% fiber and 4% beta-glucan.
In comparison, whole-wheat flour has 10.8% insoluble fiber and no soluble fiber. Spelt, a variety of wheat, has 10.7% insoluble fiber. Dark rye flour, a whole-meal flour, has 22.6% insoluble fiber. Light rye flour, which has had the bran and germ removed, has 14.6%. Triticale, a hybrid of durum wheat and rye, has 14.6% insoluble fiber and zero soluble fiber.
Processing techniques depend on the type of grain. When barley’s nondigestible hull is removed, it’s considered dehulled. Removing the bran layer (and the whole-grain claim…) yields pearled barley. In other grains, it is also possible to separate the bran to yield a beneficial ingredient. Oat bran is desirable because the bran contains most of the beta-glucan. Bran may also be separated from corn, providing a rich source of insoluble fiber.
Grains can be milled to whole flours or meals or they may be flaked. Oats may be steel-cut.
Reaching for claims
The FDA allows a “good source” of fiber claim if the food contains 2.5 to 4.9 grams of fiber per serving. If the food contains more than 4.9 grams per serving, it can be labeled an “excellent source” of fiber.
Bar developers face some obstacles when trying to deliver the recommended daily intake of fiber in a single serving, especially when relying on whole oats and barley rather than a concentrate, notes Darren Schubert, sales manager, Grain Millers, Inc., Eugene, OR. The difficulty comes in determining “how much sweetener could be added, not only for a good-tasting product, but to bind the product and hold it together,” he says. “You might be limited from a percentage standpoint of how much grain (and ultimately, how much fiber) you can put into it,” if relying completely on whole grains alone. Ingredients that bind and flavor the bar will dilute fiber delivered per serving and make it difficult to meet the daily fiber intake in a relatively small bar.