Only 5% of the US population meet dietary fiber requirements, according to the American Journal of Lifestyle Medicine. Consuming fiber-enhanced foods is one of the best approaches to meeting the daily recommended intakes, which the Dietary Guidelines for Americans 2015-2020 states as 14 grams for every 1,000 calories of food consumed. Fiber-enhanced foods help meet these targets without overconsuming calories that may lead to unhealthy weight gain.
“Adding supplemental fiber to bakery and snack items is an easy way to help consumers to get more fiber in the food products that they eat on a frequent basis,” said Katie Harris, product development and nutrition scientist, Bay State Milling Co.
This comes with challenges that vary by the amount and type of fiber. The good news is that bakers have a plethora of dietary fiber sources to work with, including intrinsic intact fibers in plants, as well as specific isolated or synthetic non-digestible carbohydrates recognized as fiber by the US Food and Drug Administration (FDA). Using one or more of these dietary fiber sources often makes it possible to achieve consumer-appealing claims. Products with 2.5 grams or more per serving may claim they are a “good source of fiber.” Those with 5 grams or more may be described with a “high-fiber” claim.
In addition to boosting fiber content, these ingredients may provide additional functions. Some, for example, contribute sweetness and reduce added sugars. Others provide creamy viscosity, which assists with partial fat replacement. Some fibers are prebiotic, functioning as fuel for healthy intestinal microorganisms, thus improving gastrointestinal health.
“Dietary fibers can also be used to aid in water holding within the food matrix of both gluten-containing and gluten-free products,” Ms. Harris said. “This allows for an optimal sensory experience for the consumer.”
Best candidates for enrichment
For certain bakery applications, adding fiber makes a lot of sense.
“Breads, certain muffins, crackers and breakfast biscuits — products generally lower in sugar and typically targeted for being healthier bakery options — have a greater chance for success in the fiber space,” said Matt Gennrich, senior food technologist, bakery applications, Cargill. “Many of the baked goods that contain higher sugar and fat content are perceived as more indulgent, and it can be harder to formulate for a fiber claim without affecting overall product performance.”
For other baked foods, including fiber isn’t impossible, but it does come with extra hurdles to clear.
“It’s most challenging to add fiber to bakery products with smaller serving sizes, since fiber claims are based on the amount of dietary fiber delivered per serving consumed,” said MacKenzie Sizemore, principal food technologist, Ingredion, Inc. “Sweet goods with delicate textures and flavor profiles can become overwhelmed when working with less refined, more flavor-forward fiber ingredients.”
There are also restrictions by the FDA regarding certain nutrient content claims. If a product is already high in fat, it might not make sense to try to add a fiber claim, as a fat content disclaimer may be necessary.
“Instead, it may be better to formulate a new product or to re-work an existing offering that has a more acceptable nutritional profile,” Mr. Gennrich said.
In general, adding fiber alters processing behavior due to differences in water absorption properties of the fibers, flours and hydrocolloids in the system. Often, finished products may be more dense, tough, dry or crumbly than products made without added fibers.
“By understanding hydration behavior, use levels and processing, the formulation may be adjusted to maximize fiber benefits and minimize changes to finished products or process,” Ms. Sizemore said.
There are three types of dietary fiber for bakers to work with. Soluble fiber, as the term suggests, is soluble in water. Some types will absorb water and form a viscous gel that traps dietary cholesterol and bile acids and carries them out of the body, while others are not viscous. They are fermentable, functioning as prebiotics to promote the growth of beneficial intestinal bacteria. Insoluble fibers are not soluble in water. They are generalized as roughage and best known for proving bulk to stool, helping to prevent or alleviate constipation. The third type, resistant starch, resists digestion in the small intestine. It is not soluble in water yet is fermented in the colon.
The options available
The three types of dietary fiber may be found intrinsically intact in plant ingredients, as well as in isolated or synthetic non-digestible carbohydrates. Some ingredients only provide one type of fiber, while others contain a combination.
Citrus fiber, for example, is about 75% dietary fiber, with equal amounts of insoluble and soluble.
“Our citrus fiber also contains about 8% protein, which is an important component for emulsification properties,” said Brock Lundberg, division president of research and development at Fiberstar. “Typically, this citrus fiber absorbs 5- to 10-times its weight in water and a similar amount of oil, depending on the application.”
Fibersol, a joint venture under ADM/Matsutani, LLC, offers a range of soluble dietary fiber ingredients that feature excellent water solubility, as well as superior stability under various processing conditions, including heat, acid, shear and freeze/thaw.
“In syrup form, it has helpful binding properties, especially in breads and bars, while the powder form is readily dispersible for easy incorporation,” said Marissa Barnes, marketing director, sweeteners and fibers at ADM.
Ingredion offers varied fiber ingredients sourced from corn, potato and tapioca. They range from 60% to 90% total fiber and provide various functions. The company’s resistant starch, for example, has been shown to increase baked product volume and improve cell structure in bread applications and increase expansion in extruded cereals and snacks. Other fiber ingredients may enhance crispiness in baked products such as crackers and cookies, due to their low water-holding capacities compared to traditional wheat flours.
“Liquid or soluble fibers can enhance softness and tender texture in baked goods like cakes and muffins, helping to keep them moist over shelf life,” Ms. Sizemore said.
Inulin and oligofructose from chicory root fiber are two of the most common isolated fiber ingredients used by bakers. They are prebiotic and come in numerous ingredient formats with varied functionalities and may be simply labeled as chicory root fiber on ingredient statements.
“They allow for easy application in most baked goods, while maintaining taste and texture,” said Kyle Krause, product manager-functional fiber and carbohydrates, Beneo. “Using our inulin and oligofructose chicory root fibers in chocolate chip cookies can raise the fiber content and reduce sugar (by 30%) at the same time, without impacting sweetness, taste and crunchiness.”
Brigitte Peters, technical sales support, Sensus, explained that because inulin and oligofructose are soluble fibers, it is easy to include them in relatively high levels in batter and dough formulations. The neutral sweet taste makes them suitable to replace sugars in sweet baked foods.
“In hamburger buns, chicory root fiber boosts fiber content while providing tenderness,” Ms. Peters said. “And in gluten-free bakery products, it can contribute to a more attractive color, taste and texture.”
Cargill often recommends replacing sugar one-to-one with chicory root fiber.
“While many bulking agents result in finished products with a crisper or firmer texture, chicory root fiber more closely mimics the texture of its full-sugar counterpart,” Mr. Gennrich said.
This article is an excerpt from the March 2020 issue of Baking & Snack. To read the entire feature, click here.