Oct. 3, 2011
by Laurie Gorton
Concern about digestive health motivates many consumers to buy foods enhanced with extra dietary fiber. While older individuals look at fiber as a natural way to improve gut function, parents also take fiber content seriously when selecting foods for children suffering “tummy troubles.” For the 38% of US consumers now managing a digestive problem, dietary fiber offers a remedy.
However, most people don’t eat enough fiber to meet even normal requirements, which experts peg at 30 to 35 g per day. “Fiber is an integral part of many natural foods such as grains, cereal products, fruit and vegetables,” said Peggy Steele, global business director, Danisco BioActives, Madison, WI, “but individuals are simply not consuming enough of these fiber-rich foods as part of the modern diet to maintain regularity and optimum digestive health.”
Recent scientific research heralds the positive role dietary fiber plays in boosting satiety and suppressing appetite to aid weight loss or control programs. This food component has long been recognized for reducing the risk of cancer, heart disease and diabetes.
“Fiber is very good for consumers,” said Rajen S. Mehta, PhD, senior director, fiber applications, SunOpta Ingredients Group, Chelmsford, MA. “They can have their cake and eat it, too.”
And it’s good for bakers because it helps control water, reduce bowl costs and minimize breakage. From a formulation standpoint, fiber fits so well into most bakery and snack products that it’s practically invisible to the product and the process. Experts agree that soluble and insoluble dietary fiber can be readily added to many foods, especially baked products.
THE SCIENCE PART.
Dietary fiber is good for the body, a fact well supported by scientific research. Extensive research also supports the safety and effectiveness of fiber-fortification ingredients in foods. National Starch Food Innovation, Bridgewater, NJ, reported more than 370 published studies involving its corn-based resistant starches and 200 studies on the health effects of short-chain fructooligosaccharides (scFOS). Numerous clinical studies verify the nutritional benefits of the soluble corn and wheat fibers offered by Roquette America, Inc., Keokuk, IA. Danisco noted more than 25 years of research and 30-plus clinical studies with its polydextrose.
Basically, three distinct characteristics of dietary fiber shape their role in digestive health: bulking, fermentation and viscosity. (See “Fiber Mechanisms”
) Rhonda Witwer, senior business development manager, nutrition, Corn Products International/National Starch Food Innovation, Bridgewater, NJ, explained the activity involved and summarized recent scientific studies. National Starch supplies NutraFlora scFOS, Purimune galactooligosaccharides (GOS), Hi-maize resistant starch and Hi-maize whole-grain corn flour.
(A detailed examination that cites recent scientific studies supporting support fiber’s role in digestive health is available here
FIT FOR USE.
Ever since 1975, when British researchers first linked dietary fiber with a reduced risk of cancer, food manufacturers have been adding fiber to nearly every category of food products. However, the best opportunities are in baked foods and snacks because of their frequency of consumption by people worldwide. That includes everything from pasta and noodles to cookies, crackers and pretzels as well as bread, buns, bagels, English muffins and tortillas.
“There aren’t many baked foods or snacks that can’t use all the fiber they can hold,” said Judy Turner, manager, food ingredient applications, Tate & Lyle (Americas), Decatur, IL. The company produces Promitor soluble corn fiber.
Consumers readily accept fiber fortification, according to Jit Ang, executive vice-president, technical services, International Fiber Corp. (IFC), North Tonawanda, NY. He even found it going into an important emerging category. “With the growing interest in gluten-free products, IFC’s fibers have been shown to improve texture, structure and taste of this product category,” he observed. IFC markets Solka-Floc powdered cellulose; JustFiber sourced from white wheat, bamboo, cottonseed, sugar cane, pea, oat and potato; and Fibrex sugar beet fiber.
Ms. Steele cited polydextrose’s low caloric load, low glycemic index and high tolerance by the body as important consumer benefits. “This allows formulation of high-fiber products that are also consumer-friendly and encourage repeat purchase,” she said. Danisco offers Litesse polydextrose.
How does fiber work in baked foods and snacks? “Fiber can be used for various reasons: cost reduction, texture, health. And there is a lot of reduction flexibility in what you can do with it,” Dr. Mehta said. He championed insoluble fiber — the kind that prevails in cereal grains — as particularly well suited to baked foods. SunOpta is best known for its Canadian Harvest oat fibers, but it also offers SunOpta soy and pea fibers; Barley-Balance beta-glucan concentrate; and Canadian Harvest stabilized oat, wheat and corn brans. “The fiber ingredients are basically flour-like and go into bakery products like flour,” he added. “Staying close to Mother Nature is good, and that’s what we do.”
High solubility, neutral taste and excellent stability qualify polydextrose for many food applications, according to Ms. Steele. It also has interesting functional properties. “It can act as a humectant in high-moisture products such as cakes and muffins, enabling them to maintain the characteristic moistness of such products for a longer period,” she said. “Conversely, thanks to its high glass-transition temperature, in low-moisture systems such as extruded snacks and breakfast cereals, it helps increase crispiness and bowl life.”
Resistant starch suppliers describe their ingredients as invisible, referring to the ease with which they can be added to bakery formulations. Neelesh Varde, PhD, senior project manager, fiber platform, Roquette America, Inc. credited this aspect to the fiber’s low viscosity and stability during thermal or shear processing.
Ms. Witwer observed that the fiber, a white powder with a bland taste, readily substitutes for a good portion of the flour in a formula, achieving “an invisible fiber boost.”
Wheat-based resistant starch has the same size, shape, surface and texture properties, flavor and sensory attributes as wheat flour, according to Ody Maningat, PhD, vice-president, applications technology and technical services, MGP Ingredients, Inc., Atchison, KS. MGP Ingredients produces Fibersym RW resistant wheat starch and its cooked version, FiberRite RW.
Whole-grain flour answers the fiber call, too. Now, micronized cereal fractions present a different approach, according to Michael K. Weibel, vice-president, R&D, Watson, Inc., West Haven, CT. The company developed Perfect Grains, a micronized blend of wheat germ and wheat bran, milled to colloidal dimensions by a proprietary process. “The milling industry has typically fractionated wheat into bran, germ and starch endosperm, recombining the bran and germ with refined endosperm to produce whole-grain flour,” he explained.
“Micronized cereal fractions are easy to use and readily incorporated into a variety of doughs,” Mr. Weibel said, noting that that fractionated cereal fibers improve both texture and consumer acceptance of finished products. The company recently extended the micronization process to high-fiber cereal fractions such as corn bran and others.
A deeper look into the wheat kernel resulted in Horizon Milling’s GrainWise wheat Aleurone. This ingredient enables incorporation of the nutritional benefits of whole grains into processed foods, according to Beth Peta, bakery marketing manager, Cargill, Wayzata, MN. In addition to its 45% dietary fiber content, it carries vitamins, minerals, antioxidants and other phytochemicals. “And it preserves the pleasing sensory qualities consumers enjoy in foods made from white flour — soft texture, high volume, mild taste and light color.” Cargill supplies a number of fiber-enhancing formulating choices: Actistar type 4 resistant starch, Oliggo-Fiber inulin, MaizeWise corn bran insoluble fiber and Barliv Betafiber concentrated beta-glucan soluble fiber.
With several exceptions such as resistant starches sourced from wheat and corn, the chief hurdle in bakery formulating will be absorption. “In general, fibers tend to absorb more water than other ingredients in the formula,” Mr. Ang said. Water levels will require adjustment depending on the type of fiber used. “Typically, longer fibers absorb and retain more water than shorter ones,” he added.
For this reason, he recommended adding fiber ingredients at the dough stage of sponge-and-dough processes, thus allowing formula water to hydrate the gluten, water that the fiber would otherwise have sequestered. Sometimes, additional gluten and emulsifiers may also be needed.
Fiber’s ability to absorb fluids works in a beneficial way, too. “In certain fried foods such as donuts, fiber can help reduce fat pickup, thus improving the nutritional properties of the end product,” Mr. Ang said. “Some fibers also improve structure and reduce breakage in baked snacks.”
Ms. Turner confirmed the usefulness of fiber in snacks foods for aiding texture as well cutting oil absorption. “We find a lot of customers using our fiber in snack chips, baked or fried,” she said.
Common formulation problems with adding fiber, according to Ms. Peta, include cardboard-like taste, dry texture, heat sensitivity, viscosity and density. “Our application scientists work closely with customers to overcome these challenges,” she said. “The best ingredient solution will always depend on the application and the customer’s product goals.”
In the end, it’s the formulator’s choice. As Dr. Mehta said, “You name it, by choosing the right fiber or fibers, you can achieve your goals.” Editor’s note: Many of the experts quoted here provided detailed explanations of fiber’s place in digestive health and bakery formulations. Watch for these expanded interviews to be featured in
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