Something to Chew On: Fiber Fortification with Gums and Starches

The revised dietary guidelines from the USDA give fiber foods a hearty endorsement. Continued research continues to link consumption of foods high in soluble and insoluble fiber with a host of health benefits ranging from good gastrointestinal health to resistance to cancer and heart disease.

“We’re witnessing a tremendous amount of activity around fiber,” says Dorothy Peterson, product line consultant for starch and derivatives at Minneapolis-based Cargill Inc. (www.cargill.com). With much of its $40-plus billion in sales in milling and processed foods, Cargill sees enormous possibilities for fiber profit as both an ingredient provider and a value-added food manufacturer. “A lot of the activity is in response to the new dietary guidelines,” Peterson admits.

Decades of research link heart health and cancer-preventive properties to fiber consumption. What’s added to the growing interest in fiber by consumers and processors is the rapidly growing understanding of the mechanisms by which fiber works and a lengthening list of health benefits.

A Matter of Structure

Fiber is a carbohydrate not digested by enzymes in the upper intestine but fermented by bacteria in the lower intestine. Probiotic bacteria in the lower intestine need to be fed, and fiber is their favorite food. Without adequate fiber consumption, these bacteria cannot fulfill their function. Some research indicates a dearth of such probiotic bacteria could leave the colon susceptible to cancer.

Fiber also slows absorption of glucose, the usable energy product created by the breakdown of starches, into the bloodstream. With a rapidly growing number of Americans concerned with obesity and diabetes, controlling glycemic load has become a primary health initiative.

Makers of cereal and bakery products have been phasing fiber into their products for years, yielding robust sales in the consumer acceptance of the hearty flavor and wholesome, “natural” image of fiber-rich baked goods.

With all the forms of fiber available, the potential to fortify a wide range of products, including beverages and meats, opens health-based marketing opportunities. Add fiber’s abundant functional qualities to the mix and you can easily imagine fiber-added products streaming down the new product pipeline at a mind-boggling rate.

Gumming Up the Works

The functional qualities that put fiber processing formulations can also make them problematic in certain applications. Adding even small amounts of fiber to a formulation may gum up equipment or alter flavor or texture in an established product. Furthermore, to reap both the health and market benefits of fiber-rich products, the foods must contain a critical amount of fiber.

“You face matters of taste and functionality when you deal with fiber in food products,” explains Richard Black, vice president of global nutrition for Kraft Foods, Northfield, Ill. (www.kraftfoods.com). “If you use too much, you may destroy the taste. If you use too little, what’s the value? You won’t be able to make a label claim. You must overcome consumer expectations. A lot of consumers equate high fiber with cardboard taste. And functionality is always important.”

Cereal processors like General Mills and Kraft’s Post brand are pursuing fiber via the “whole grain” route, banking on the flavor reputation and health connotation of the easy-to-grasp equation: whole grain equals goodness. But adding fiber to products outside of bakery and cereal poses frequent and substantial formulation challenges.

“Manufacturers are after ‘invisible’ fiber,” says Cargill’s Peterson. She defines invisible fiber as one that has virtually no effect on flavor, texture or the process. A fourth characteristic might be label invisibility – fiber’s appearance under a commonplace ingredient name. A resistant starch, for example, might be subsumed under the label listing of a common starch. In the invisible category are resistant starches, fructooligosaccharides, cellulose and gums.

Function Follows Form

Gums and starches are mainstream categories of fiber-bearing ingredients. They’ve been customized into literally hundreds of forms. In the right formulation and combination, they can offer significant fiber benefits with minimal effect on formulation or variation from the end product standard.

How the various fibers and their customized variants interact with water is often the key to their selection. Gum arabic, an emulsifier soluble in water, keeps beverage products from separating into layers. Other gums add viscosity or pleasing texture or mouthfeel.

Most fat-reduced products rely on starches and gums and their ability to regulate moisture to help simulate the bulk and mouthfeel of the removed fat.

The solubility of gums has made them useful ingredients for adding fiber to beverages and other foods with minimal effect on formulation. Soluble fiber binds the bile acids made from cholesterol and used to digest fats. Trapping and removing bile acids indirectly reduces blood cholesterol levels. Gums – guar and acacia, for example — are comprised largely of soluble fiber.