The USDA Dietary Guidelines for Americans recommend consumption of 25g-38g of fiber per day, but Americans receive only 15g/day on average. This difference between actual and recommended consumption is now popularly known in the food industry as the “fiber gap.”

“Of the nutrients we consume, dietary fiber consumption lags the most,” says Steven Young, principal of Steven Young Worldwide, a dairy and food consulting firm. He estimates there is a fiber gap of approximately three billion pounds of TDF (total dietary fiber) equivalent.

Young suggests that beverages are the perfect vehicles to deliver the missing TDF. Traditionally, fiber-enhanced beverages have been formulated with viscous fibers such as psyllium, for example; in some instances, the label warns consumers that it could cause a choking hazard. It is difficult to easily translate fiber into refreshing beverages like juices, teas and sports drinks, which consumers are more accustomed to drinking daily.

Solubility Above All

Typical insoluble fibers are unsuitable for light, clear beverage applications due to their lack of solubility, as well as their color and flavor limitations. They tend to separate and precipitate during storage. Even when “stabilized,” water-insoluble fibers can result in thick, grainy, coarse beverages with less than acceptable sensory characteristics.

“The most desirable fibers for use in beverages are soluble in water and do not need stabilization or suspension,” says Schmelzer.

The benefits of soluble fiber include: reduction of LDL and total cholesterol; prebiotic effects; and potential beneficial effects on glycemic control, triglycerides and blood pressure. Some soluble fibers have a laxation effect, and others like inulin, for example, help boost calcium absorption.

“Soluble viscous fibers such as psyllium or other high molecular weight hydrocolloids and gums tend to be slimy and give an undesirable mouthfeel,” observes Schmelzer. There are several different types of pectic substances (e.g., pectin, low-methoxyl pectins, and polygalacturonic acid) that could be used in beverage applications. However, many of these pectic substances create high viscosities and gel under certain conditions, warns Young.

Some also have the ability under certain conditions to tie up minerals like calcium. In addition, adding pectic substances at the levels necessary to make dietary fiber claims can be cost prohibitive, Young adds. Recently, however, researchers at the University of Florida's College of Medicine have re-engineered certain pectins by complexing proteins to them, significantly reducing viscosity.

“An optimal soluble fiber must not add color or flavor of its own, nor modify naturally occurring or added colors, add possible “gastric distress” when consumed, or be microbiologically incompatible (for example, with cold-filled carbonated beverages) with the applications at hand,” says Young. Most importantly, fiber should provide a regulatory basis for a nutrient content or similar claim without changing the aforementioned sensory features of the product. Not all fiber sources are compatible with these needs.

To spur an onslaught of fiber-enriched foods, the FDA recently announced that whole-grain barley and barley-containing products are allowed to claim they reduce the risk of coronary heart disease (CHD). To qualify for the health claim, the barley-containing foods must provide at least 0.75g of soluble fiber per serving of the food.

Beta-glucan is the soluble fiber found in barley. Traditionally, beta-glucan-containing ingredients have imparted a significant increase in viscosity of beverages, resulting in an undesirable mouthfeel and texture. A new, highly concentrated (70% purity) barley beta-glucan product has been developed, which can be readily formulated into low-viscosity juice drinks. “This barley beta-glucan does not contain any insoluble material; therefore, it does not precipitate over time,” offers Janice Johnson, a principal food scientist working on the new product. Clear beverages containing this ingredient will have a faint cloudy appearance.

Staking a Fiber Claim

When selecting fibers for a fiber-fortified beverage, manufacturers should consider the robustness of the flavor system, says Schmelzer. Some fiber sources can contribute off-flavors, such as cereal or citrus notes, which may not be compatible with the beverage.

Color is one of the key challenges of adding fiber to a clear beverage application. The problem is particularly noticeable when fiber is added at levels necessary to make nutrient content or structure/function claims. If the fiber ingredient consists of only 50% fiber, then 5g must be added to get 2.5g of fiber. At greater than 5g of fiber per serving, a product can be marketed as “high in,” “enriched” or “enhanced” with fiber.

“Many times, fiber ingredients that are water-white [i.e., clear and colorless] at low levels, are not so at levels necessary to make an appropriate nutritional claim,” says Young. “It may be clear; it just may not be water-white.” Digestion-resistant maltodextrin (DRM) is a domestic source of water-soluble fiber that generally will not interact with other nutrients or constituents of juices, including naturally occurring or added colors or flavors.

DRM is a clear, colorless, flavorless and odorless dietary fiber that is 90%+ indigestible in humans. The product is made by modifying the amount of heat and acid that is applied during the manufacturing of maltodextrin. During this process, a high percentage of digestion-resistant chemical bonds is created, making the final product indigestible by human digestive enzymes; it also is heat and acid stable.

Fiber in Function

It is absolutely possible to formulate fiber into a clear carbonated beverage, says Young, but manufacturers should keep in mind that soft drinks are only preserved by acid and carbonation (pH levels in the range of 4.0-4.5 need added anti-mycotics). “Considering processes such as standard pasteurization, UHT processing, retorting and hot filling, heat and acid stability is incredibly important to beverages and other foods as well.

“Natural fiber 'extracts' aren't typically manufactured under rigorous thermal and/or acid treatments and, therefore, can be quite labile, or sensitive to standard heat and/or acid processing,” he says. In an acidic product like orange juice, for example, dietary fibers can break down during and after manufacturing. This results in lower than expected TDF levels (fiber hydrolysis) and higher than expected sugar levels (release of simple sugars during fiber hydrolysis). Thus, the finished food could be out of regulatory compliance both on TDF and sugars, and sweeter than expected. This, in turn, can cause changes in finished product flavor and other sensory attributes.

Neutral pH beverages have a wider array of fiber options, while acidic beverages (less than 4.1 pH) will require a fiber with good acid stability. “Also, certain fibers and gums can interact with proteins, causing sedimentation or phase separation, which can be exacerbated closer to the isoelectric point of the protein,” says Schmelzer.

Lower pH beverages can be more challenging for fiber fortification. “In particular, carbonated beverages manufactured from concentrated throw syrup can provide a unique challenge,” states Schmelzer. Factors to consider in concentrated syrups include the solubility of the fiber, its susceptibility to lower pH and its impact on the overall viscosity of the syrup. Generally, if a fiber is susceptible, product developers will need to account for the impact of the time/temperature profile during beverage processing, as well as the product's pH. The new barley beta-glucan product performs very well in all typical pH levels associated with beverages.

Since these reactions can occur inside the beverage container after manufacturing, package-to-package variation can occur. Thus, one ends up with differing sensory characteristics and out-of-compliance packs. “The ultimate challenge is trying to deliver the consistent sensory and nutritional declarations serving-to-serving; package-to-package; lot-to-lot throughout the full, intended shelflife of the product,” says Young.

De-stressing Fiber

“One could make the case that DRM has the physical ingredient properties of a 100% water-soluble fiber source yet shows many of the nutritional benefits of both water-soluble and water-insoluble dietary fibers,” says Young. Since DRM is only partially fermented in the colon, slower development of acid and gas in the colon means virtually no “gastric distress” on consumption of large amounts of DRM, he explains. “This is a clear mark of differentiation between DRM and other soluble fibers.” In addition, DRM's ultra-high indigestibility has virtually no effect on blood sugar. This, in turn, results in an ingredient with an ultra-low Glycemic Index (GI < 5 vs. glucose = 100).

Both barley beta-glucan and inulin are fermented in the colon. The amount of barley beta-glucan that is needed for a health claim is 3g per day. In a recent clinical study, individuals consumed either 3 or 5g of barley beta-glucan daily, via cereal and juice drinks. “Among the 155 subjects in the study, a few initially experienced mild gastrointestinal effects (e.g., mild gas, bloating),” says Lore Kolberg, a regulatory and scientific affairs manager at a barley beta-glucan company. These effects disappeared after the first couple of weeks of the study. “Such side effects are common when fiber intake is increased,” adds Kolberg. “The body generally adapts to the increased fiber intake.”

Inulin and fructo-oligosaccharides (FOS) sourced from banana, chicory and other extracts are very popular and widely available. In addition, inulin promotes satiety and digestive health because of its prebiotic characteristics, says Joe O'Neill, national sales manager at an inulin supplier.

However, although they are naturally occurring, some forms are very aggressively fermented (nearly 100% fermented) in the colon, states Young. “This can cause rapid development of acid and gas with little opportunity for that acid and gas to dissipate, resulting in gastric distress.” Formulators should thus take care to use such ingredients at appropriate levels.

Flipping over Fiber

Hydrocolloids are not particularly suitable for clear, refreshing beverages because they have incredibly large molecular weights and want to bind lots of water. “This is good as a functional ingredient at low use rates, but not desirable at higher use rates when fortifying a beverage for a fiber claim,” Young adds. DRM does not bind water well but in systems where it does, it gives up that water easily and quickly, whereas many gums will not release any bound water.

Fiber can be added to beverages of all types: water- or milk-based drinks, tea or coffee, juices or sports drinks. Formulating fiber into beverages is a straightforward and easy execution if the proper dietary fiber source is selected. This is especially true when compared to fortifying other foods with fibers that might require “processing gymnastics” to obtain nutrient content or other similar claims.

“There is a true need for dietary fiber supplementation in the American diet. Eating fruits and vegetables is highly preferable, but you can't expect people to literally double up on consumption of fruits, vegetables or salads during the course of a day,” offers Young. “With the right dietary fiber ingredient, it is possible to deliver a lot of dietary fiber in a small volume. Beverages can play a huge role to help fill the fiber 'gap' by providing dietary fiber in a concentrated and pleasing way.”

Showcase: Alternative Sweeteners; Dietary Fiber and Bulking Agents

ORAFTI offers groundbreaking nutritional and functional properties with the soluble, all-natural fiber Beneo™ (inulin, oligofructose) and Beneo Synergy 1. Healthy benefits include improved calcium absorption, “invisible” fiber enrichment, improved mouthfeel and enhanced gastrointestinal health through prebiotic abilities. Beneo replaces fat and sugar in food, beverage and nutraceutical applications, without adversely affecting taste or mouthfeel. Beneo Synergy 1 offers enhanced calcium absorption at lower use levels. ORAFTI operates in more than 75 countries globally. ORAFTI, Kathy Niness, 610-889-9828, www.orafti.com

Low-glycemic index (GI) foods frequently are high in dietary fiber, and can assist in maintaining healthy blood sugar and serum insulin levels. Fibersol-2, a 90% soluble dietary fiber/digestion-resistant

maltodextrin marketed and sold by Matsutani America Inc., has a low GI index—a value of less than 5 based on glucose having a value of 100. Its presence can help lower the GI value of a finished product. Low-GI foods can help with weight loss, diabetes, hypoglycemia and coronary heart

disease. The ingredient is odorless, tasteless and stable in virtually all

processing conditions. Matsutani America Inc., Bob Heard, 217-875-4490, bheard97@aol.com

Pizzey's SelectGrad and BevGrad Milled Flaxseed ingredients offer ALA omega-3 fatty acids (22%), lignans, dietary fiber (27%), antioxidants and other phytonutrients. Flaxseed now qualifies for a nutrient content claim (only 260mg of ALA omega-3 is required for a “Good,” “Excellent,” “Rich” or “High” source of omega-3) and structure function claims such as “ALA omega-3 fatty acids support cardiovascular health,” among others. BevGrad, a finely milled, pasteurized flaxseed powder, is an ideal nutritional enhancement for beverages, and provides a smooth, creamy texture. Pizzey's Milling, Mary Ekman, 847-775-1400, mary@pizzeys.com

GTC Nutrition offers NutraFlora® short-chain fructo-oligosaccharides (scFOS®) natural prebiotic fiber, which is uniquely capable of promoting health by improving the absorption of calcium, magnesium and soy isoflavones, and maintaining healthy digestive function and immune response. NutraFlora also provides many positive functional benefits including adding fiber, enriching flavors, improving moistness, lowering carbohydrate content, and increasing the shelflife of a wide variety of products. GTC Nutrition, John Musselman, 303-216-2489, jmusselman@gtcnutrition.com

Frutalose‚ L85 from Sensus America is a sweet liquid inulin, extracted from chicory roots, consisting of 85% soluble dietary fiber. A natural ingredient, it has a pleasant sweetness (50% vs. sucrose: 100), a low caloric value (1.9 Kcal/g, dry basis), and a low glycemic index (20 vs. glucose: 100). It can replace sugars and sugar alcohols to develop reduced-sugar, low-calorie and fiber-enriched food products, and masks the aftertaste of high-intensity sweeteners. Food products containing this ingredient can make claims like “fiber-enriched,” “good/excellent source of fiber,” “sugar-reduced,” “prebiotic” and “low-calorie.” Sensus America LLC, Connie Lin, 646-452-6146, connie.lin@sensus.us, www.sensus.us

Chr. Hansen produces natural sweeteners including molasses, malt, rice, oat, honey, invert sugar and reaction syrups. All-natural ingredients are ideal for natural foods. Also, organically certified malt extracts and rice syrups and grain conversion products offer high nutritional value. The hypoallergenic rice syrup is ideal for bakery, cereal, confection, beverage, soup and sauce applications. The company provides technical assistance and competitive pricing. Customized blends for specific customer applications are available. Chr. Hansen, Jim Funk, 800-558-0802, jfunk@chr-hansen-us.com, www.chr-hansen.com

Tate & Lyle's Beverage Rebalance™ 601 solution set provides well-balanced sweetness for fresh, fruity flavored waters that taste great and are low in sugar. Beverages made with the set contain up to 85% fewer calories per serving, when compared to sugared beverages of comparable sweetness. This set is compatible with calcium citrate and additional vitamins, which allows for more targeted nutritive benefits, and can be used in a variety of beverages. Tate & Lyle, U.S. consumer inquiries, 800-526-5728

Low-moisture apple fiber from Tree Top's Ingredient Group is an excellent source of dietary fiber. This shelf-stable, free-flowing powder gives food and beverages the added benefit of fiber, as well as a palatable texture and neutral flavor. Additionally, with the release of the 2005 Dietary Guidelines, Tree Top created the Fruit Serving Calculation Guide to help processors calculate how many grams of fruit ingredients to add to a formula to achieve a portion or a whole serving of fruit. Tree Top Ingredient Group, Jeannie Swedberg, 509-698-1435

CAVAMAX® W6 is a new, colorless, soluble dietary fiber with exceptional properties. This natural soluble fiber is not digestible, yet fully fermentable. Solutions are clear, colorless, with low viscosity and neutral taste. CAVAMAX W6 is heat stable, even under strongly acidic conditions, stable in carbonated beverages, and no browning is seen in complex food systems. In comparison to many soluble fibers, CAVAMAX W6 is not hygroscopic. Initial clinical studies show the effect of CAVAMAX W6 in lowering the Glycemic Index of starch-containing foods. Wacker Chemical Corporation, Helmut Reuscher, 517-264-8794,

helmut.reuscher@wacker.com

All the benefits of starch-based sweeteners are now available for organic and non-GMO beverages with the use of neutral-flavored BriesSweet™ Tapioca Syrups. Increased body and mouthfeel with a variety of sweetness intensities and profiles are available from 28, 42 and 63 dextrose equivalents as well as high maltose. The company also offers the bulking agents BriesSweet Tapioca Maltodextrin 3 DE and 10 DE. These all-natural, non-GMO powders can easily be incorporated into wet or dry beverage formulations. They provide bulking and nutritive solids to beverages while maintaining low osmolarity to aid in proper water absorption. Briess, Ann Heus, 920-849-7711, info@briess.com

Danisco Sweeteners offers Litesse® polydextrose, a prebiotic fiber that is also widely used to reduce calories and replace sugar. Unlike some other prebiotics, Litesse has a sustained effect throughout the entire intestine, is less likely to cause the lactic acid accumulation that can lead to gastric discomfort, and is well tolerated. Litesse is an effective prebiotic applicable to a variety of nutritious foods for optimal digestive health. Danisco Sweeteners, Donna Brooks, 800-255-6837, ext. 2521, donna.brooks@danisco.com, www.danisco.com/sweeteners