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January 5, 2006
We know it’s good for us, but most of us are getting less than half of FDA’s Daily Reference Value for fiber. Rather than the recommended 25 grams of fiber in a 2,000-calorie diet, we struggle to reach 13 grams. Our consumption is so low that the USDA’s Dietary Guidelines for Americans report published in 2005 cites fiber as a nutrient whose consumption is low enough to be of concern and states efforts are warranted to promote increased dietary intake. USDA recognizes that a diet rich in dietary fiber promotes healthy laxation, reduces the risk of type 2 diabetes and decreases the risk of coronary heart disease.
While the government and health agencies such as the American Heart Association, Dallas; the Mayo Clinic, Rochester, MN; and the American Dietetic Association, Chicago, urge Americans to eat more fruits, vegetables and whole grains to increase general fiber consumption, how can the food industry help?
Rhonda Witwer, business development manager, National Starch Food Innovation, Bridgewater, NJ, sees it clearly. “We’ve got to build the fiber intake in this country,” she notes, “and baked goods have got a tremendous opportunity to deliver those products.”
But adding fiber to baked goods brings a host of challenges, both from a product-development standpoint and from a consumer standpoint. The developer must choose a fiber source that blends well with the product concept, as well as the other ingredients. Texture, flavor, color and particle size are attributes that should be considered. With the inclusion of one new fiber ingredient, the finished baked good might brown undesirably or become grainy.
Fiber’s water-holding capacity can impact the machinability of the dough, as well the finished mouth-feel, be it crisp or chewy. The final product must align with consumer expectations, or it is destined for failure. Consider a dense, bran-laden angel food cake for an example of fiber fortification gone awry.
It’s sometimes called bulk. Old-timers call it roughage. Essentially, fiber is an indigestible complex carbohydrate. Simply put, it’s the parts of plant foods that the body can’t absorb.
There are two types of fiber: water-insoluble and water-soluble. Insoluble fibers — those that do not dissolve in water — include cellulose, hemicellulose and lingnin. Soluble fibers include gums and pectin. In general, soluble fibers can greatly increase a product’s viscosity and water requirements compared to insoluble fibers. The texture imparted by soluble fibers is best described as “gummy.” Insoluble fibers, on the other hand, tend to give a drier mouth-feel. In baked goods, “soluble fibers can often inhibit fermentation and proofing processes in breads,” says Jit Ang, executive vice president, International Fiber Corporation, North Tonawanda, NY. “Most breads use insoluble fibers. Soluble fibers are not normally used in bread applications.”
From a health standpoint, solublee and insoluble fibers have different roles. As insoluble fiber passes through the body, it moves waste quickly, possibly reducing the risk of colon cancer. Insoluble fiber is found in grains, nuts and vegetables. Soluble fiber helps lower blood-cholesterol and glucose levels. Good sources of soluble fiber are fruits, vegetables and certain grains, such as oats and barley. All fiber takes up space in the stomach and adds to the feeling of fullness, making it important to weight loss. High-fiber diets are usually less “energy dense,” meaning that they have fewer calories per volume of food.
The American diet is fiber-deficient partly because we don’t consume enough fruits and vegetables. The majority of us eat less whole foods in favor of the more-processed variety. This is especially true from a baked-goods standpoint. Refined white flour, from which the bran, germ and endosperm have been stripped away, has predominated in the market. The dietary fiber in 100 grams of enriched, bleached, all-purpose white flour is just 2.7 grams. Compare this to 100 grams of 100% whole-grain wheat flour, at 12.2 grams of fiber, and one path to fiber inclusion in baked goods is clear.
Replacing some or all of the wheat flour with a whole grain can add fiber to breads, cookies and crackers. “Usage level could be anywhere from 30% to 100% substitution with whole-grain flour,” says Tania Sant, R&D project manager, The Hain Celestial Group, Inc., Azusa, CA.
Many common flours beat the fiber content of white wheat flour: Rye flour has 14.6 grams of fiber per 100 grams. Oat flour has 11.5 grams, barley flour has 10.1 grams, corn flour has 10 grams and buckwheat flour has 10 grams. Besides boosting the fiber content of baked goods, they provide valuable nutrients. “Nutritionally, these flours contribute B vitamins and phytonutrients present in the bran layer of the grain,” says Sant. “Protein and vitamin E are present in the germ of the grain.”
Unique grains like quinoa, amaranth, spelt and kamut (with 5.9%, 15.2%, 11.4% and 19.2% fiber, respectively) are finding use in breads, crackers, bagels and tortillas. “We’re seeing more uses of exotic grains,” says Cynthia Harriman, director of food and nutrition strategies, Oldways Preservation Trust and the Whole Grains Council, Boston. “These are realistically only available to small producers, as the big guys would swallow the worldwide supply of some of these niche grains with three weeks production!”
Sant is optimistic about the future supply of whole grains. “I am sure suppliers will rise to the occasion if there is a demand,” she says. “There is a trend toward making whole-grain claims and, therefore, using whole-grain flours as a partial or full substitution will be more commonplace in the coming years.”
Some grains shine in certain applications but not in others. Most everyone is familiar with the flavor and desirable texture that oats can add to certain cookies and cakes. Brown rice flour is less well known, but could be an important tool in applications where crispness is desired. In cakes and cookies, however, brown rice flour can make the product gritty if used as a complete replacement for white flour.
When using whole grains, “texturally, the product will be denser, but one can overcome some of that with clever use of leavening agents,” says Sant. “The flavor contributed by the wheat, barley and oat flours could be favorable or unfavorable, depending on the application. Tannins in the bran contribute to that.” The stronger flavor and texture could mesh well in a bran muffin or multigrain bread. However, it might prove offensive in a yellow cake or sugar cookie. In applications where reliance on gluten development is high, such as breads, it is recommended to add gluten to a formula low in wheat flour to maintain dough consistency.
For many kids, not to mention adults with white-bread tastes, the flavor and/or textural perception of whole grain is a turnoff. However, one breakthrough ingredient might provide a solution. “It’s a 100%-whole-grain wheat flour that combines the nutritional benefits of whole grains with a taste and texture similar to white-flour products,” according to Garth Neuffer, spokesperson, ConAgra Food Ingredients, Omaha, NE. “Because it has a lighter color, sweeter, milder taste and is ground to a finer texture similar the refined white flour, Ultragrain can be used as 100% substitute for traditional white flour in any number of products, including breads, buns, bagels, rolls, wraps, tortillas, muffins, noodles, pizza crusts, waffles, French-toast sticks, snack and cereal bars. As such, it will deliver all the whole-grain nutrition — fiber, B vitamins, minerals and phytonutrients — as any 100% whole-wheat product. As a replacement for refined white flour, many foodservice and food manufacturers have begun using Ultragrain in a mix with white flour to deliver a taste as close as possible to what consumers have come to expect from the products they have grown to love.”
Sara Lee’s Soft & Smooth “Made With Whole Grain” white bread utilizes 30% white whole-grain flour in place of traditional white flour. A tortilla used for whole-grain burritos replaces 50% of the regular flour with this ingredient. In a line of whole-grain pizzas dubbed “The Max,” white whole-wheat flour replaces 50% of the white flour. “Kids can’t tell a difference,” Neuffer says. “Each slice of pizza contains at least one serving of whole grain.” More than 2,600 U.S. school districts are serving these pizzas.
Eventually, Neuffer sees white whole-wheat flour completely replacing refined white flour: “This may well evolve over time as consumers grow accustomed to Ultragrain, which has a taste and texture similar to refined white flour but does have its own discernable character. When used as a replacement for whole-wheat flour or in new products, we expect more manufacturers will use Ultragrain closer to the 100% level to get the full benefit of its whole-grain goodness.” The flour is available in hard white wheat (12% minimum protein) and soft white wheat (9% minimum protein).
Just switching to whole grains will make a dent in our fiber deficit, but it won’t take us all the way there. “Whole grains make an important contribution to our fiber needs, but it’s important to remember they can’t carry the entire fiber load for our diets,” says Harriman. “Most adults are advised by the new guidelines to eat about six ‘ounce-equivalents’ of grain daily. This means an ounce of finished product, containing on average 16 grams of grain ingredients. If someone ate the minimum 3 servings of whole grains — 3 times 16 equals 48 grams — he or she would get 5.9 grams of fiber if the products were made with whole-wheat flour. If someone ate all six grain servings as whole grains — rather than half and half refined and whole grain — he or she would get almost 12 grams of fiber from these whole grains.”
Rather than add fiber-rich whole grains, product designers can add fiber itself — and they have many reasons to do so. “You might be using fiber to give a higher fiber content so you can label it as a ‘good source’ or an ‘excellent source’ of fiber,” says Ang. For any fiber claim, a food must be low in fat or it must state total fat content in conjunction with the fiber claim. A good source of fiber must contain at least 10% of the RDI per reference amount; 25 grams is the RDI for fiber in a 2,000-calorie diet. An excellent source of fiber must contain at least 20% of the reference amount.
Besides health reasons, designers might add fibers to food products in order to garner a reduced- or low-calorie claim. “Fibers take up bulk but don’t contribute any calories,” Ang says. “The legal caloric content of a fiber is dependent on its insoluble-fiber content. Insoluble fiber is considered to be zero calories while soluble fiber is considered to contribute 4 kcal per gram. Cellulose, cottonseed, wheat and bamboo fibers contribute zero calories. Sugar-beet fiber provides 0.6 kcal per gram.”
Special processing can create functional fibers that might add to the nutritional profile of the finished product, but they probably won’t bring the level up to a health claim. “We produce a whole line of products that deliver specific functions when used in a food product, but the amount that is used in a food product is relatively small, which means that although you are adding fiber in your formulation, you really can get no fiber claim from it,” Ang says. A fiber might be used as a fat mimetic to replace some of the functions of fats, or a product designer might used a functional fiber in a muffin or a cake-type product to improve texture, shrink control, volume or color. Typically, 1% of the functional fiber is used in bakery applications. “Cakes, muffins, donuts and other similar food products tend to use functional fibers to give them a certain advantage that would improve a certain property in the final food product,” he continues. “That has nothing to do with fiber fortification.”
When seeking fibers to add nutritional impact to baked goods, Ang suggests thinking first about the marketing parameters. “If you only care about having the fiber claim, then you have more choices to work with, including cellulose,” he suggests. “Normally, cellulose is the most-economical source of fiber.” However, marketing might dictate the inclusion of a certain fiber to attract purchase interest — for example, wheat fiber.
It’s also important to consider compatibility. If making a cake, cookie or muffin, try to pair it with a fiber that has the right particle size, Ang advises. “Typically, if you’re going for fiber fortification, a relatively fine powder or a relatively fine, small-particle-size fiber works well,” he says. “A fine particle size is typically between 20 to 40 microns in fiber length.”
Color might affect the fiber choice, such as when making a white sandwich bread. “Some fibers are creamy-colored, some are yellowish and some are real white,” says Ang. Wheat, oat and soy fibers typically have a yellow cast. Cellulose is the whitest, followed by bamboo and cottonseed.
It may also be important to take into account the water-retention properties of the fiber. “If you’re trying to make a crunchy product, you definitely want a fiber that doesn’t hold onto as much liquid as, say, if you are trying to make a soft, moist, chewy cookie,” says Ang. “With insoluble fibers that are cellulosic in nature, longer fibers tend to hold onto more water than shorter ones.” Most fibers hold at least three times their weight, though longer fibers might retain as high as 10 times their weight in water. A gram of wheat fiber with an average length of 35 microns will retain 3.5 grams of water. If that same fiber is processed to a length of 400 microns, it will retain 10 grams of water.
Bamboo, a relatively new fiber ingredient, functions much the same as other fibers in bakery applications, but it is unique in that it works well in frostings or icings. “Due to its flexible nature, the bamboo fiber tends to give you a creamier mouth-feel,” says Ang. “Most other fibers give you a chalky, gritty mouth-feel. But with bamboo, the amount of chalkiness or grittiness is reduced significantly.”
Consumer perception can be a factor. Consumers are becoming more accepting of labels that list “cellulose” as an ingredient, suggests Ang. “More and more consumers are getting educated,” he says. “They are beginning to understand that there is really no difference between cellulose and some other fibers, except in what you call the ingredients. Cottonseed is sometimes labeled ‘vegetable fiber.’” Cottonseed fiber is very commonly used in bakery products.
If the ability to label a product natural is important, then sugar-beet fiber is recommended. Ang says that many fibers may be labeled as ‘fiber from a natural source,’ but most of these have come into contact with chemicals. For those who want to have a natural and organic claim, an organic version of sugar-beet fiber is available. What further differentiates sugar-beet fiber is its high content of soluble fiber. “When you look at the composition of wheat, bamboo or cottonseed, they are mostly insoluble,” he says. “The sugar-beet fiber is made of two different kinds of fiber. It contains an insoluble-fiber fraction, as well as a soluble fiber.”
Usage levels of fiber will vary based on labeling requirement, application and finished-product attributes. But, as a general rule, insoluble fibers can make up from 4% to 9% of the formula. “If you add multiple types of fibers, you can probably, in some cases, approach 15% to 20%,” Ang says. “It is really dependent on the product you are trying to make. My advice is, if you can, use more than one source of fiber in your product. Typically, if you go very high with one kind of fiber, chances are, you can get to where you want. But you can get a better product if you don’t just concentrate all the fiber in one source.”
Adding prebiotic fiber to baked goods can provide both nutritional and functional benefits. From a health standpoint, these fibers increase beneficial microflora. Additionally, they offer the health benefits of soluble fiber. Inulin is a naturally occurring carbohydrate — fructooligosaccharides (FOS) — typically derived from chicory root. “Inulin is a general term used to describe chains of fructose molecules with anywhere from 2 to 60 units connected with beta 2-1 bonds,” explains Hilary Hursh, food and nutrition scientist, Orafti Active Food Ingredients, Malvern, PA. “FOS or oligofructose is a more-specific term to describe short chains of fructose with 2 to 10 units. All FOS is technically inulin, but not all inulin is technically FOS.”
Both inulin and FOS can be added to baked goods. “These fibers can be used for sugar replacement or for replacing a portion of flour to boost fiber content,” Hursh continues. “Inulin is best suited for yeast-raised applications, while both ingredients work well with chemical-leavened systems.” Usually, inulin and FOS are added to baked goods at a level needed to achieve a fiber claim. “Inulin is commonly added to whole-grain breads at a level of 2% to 6% of flour weight to increase rise and improve texture,” she notes. “Inulin and oligofructose contribute nutritional benefits without a negative impact on texture or flavor. These fibers work very well in conjunction with highintensity sweeteners and polyols and even contribute to Maillard browning, which is often lost in reduced-sugar or sugar-free products. Additionally, inulin and oligofructose do not absorb water like other fibers, making it possible to achieve a crisp cookie with an excellent source of fiber.”
Litesse® polydextrose from Danisco Sweeteners, Ardsley, NY, is a polysaccharide digested as a dietary fiber that does not impart any sweetness. This nonglycemic specialty carbohydrate yields a wide variety of physiological benefits, such as a sustained prebiotic action. “It is frequently used in sugar-free and reduced-sugar cakes, cookies and other sweet baked goods,” says Donna Brooks, product manager, Danisco Sweeteners. “It works well in combination with other polyols, such as lactitol, and with high-intensity sweeteners. Litesse alters the thermal setting properties of baked goods by delaying the gelatinization of starch and, therefore, serves as a very effective low-calorie replacement for sucrose. Litesse will undergo Maillard browning reactions similar to reducing sugars and, therefore, has potential as a browning agent in baked goods.”
In cake mixes, sugar-replacement levels above 50% might reduce the air-holding capacity of the batter and increase the batter flow tendencies. Biscuit dough containing this polydextrose will also see some increase in flow, and the resultant product will be slightly harder, producing crisp and light eating characteristics in thin products. It is labeled as “polydextrose” in the ingredient statement.
Arabinogalactan, extracted from larch trees, is a relatively new ingredient. “It’s a dietary fiber greater than 90% soluble fiber as measured by AOAC method,” says Lori Siegler, marketing manager, Larex, Inc., White Bear Lake, MN. “For anyone who’s looking at adding fiber to a baked good, it also can help with moisture retention. It can be effective in helping to lower water activity. It has some filmforming properties that can help to extend shelf life. It can help with texture improvement in baked goods, improve dough handling by reducing stickiness of the dough and improve external symmetry.”
Designers have used arabinogalactan at 2% to 10% in bakery products, depending on the product. “What differentiates our prebiotic fiber from some of the others on the market is that it ferments very slowly, so you don’t get some of the negative side effects that you can get from fibers or prebiotic fibers, such as gas and bloating,” says Siegler. “Some of the FOS ferment very quickly, and it’s the fermentation that causes some of the discomfort that you can get from fibers.”
In the world of fiber, resistant starches are shaking things up. Though usually labeled as “starch,” they are unique. “Resistant starch resists alpha-amylase digestion in the body and passes to the large intestine where it is broken down similar to dietary fiber,” says Steve Ham, director of marketing specialty ingredients, MGP Ingredients, Inc., Atchison, KS. Resistant starches fall into the following classes: RS1, a physically inaccessible starch found in seeds and legumes; RS2, a granular, ungelatinized starch found in green bananas, potatoes or high-amylose starch; RS3, a retrograded starch formed after gelatinization; and RS4, a chemically modified starch that resists digestion.
Resistant starch has some characteristics that simplify its use in baked products. “Visually, there’s a difference between a traditional fiber and resistant starch,” says Ham. “Resistant starch is a very fine white powder, whereas most traditional fibers, like bran or other plant-based fibers, are more visually apparent in foods. These visual aspects help make the resistant starch attractive in applications that may not be traditional high-fiber products, like a blueberry muffin or a waffle. Using resistant starches, a formulator can convert those products to a high-fiber version while still maintaining the sensory properties that consumers expect. We refer to it internally as the ‘invisible fiber,’ because it performs like a fiber but it doesn’t have the appearance or texture of a traditional fiber, which lends some real benefits to a wide range of applications.” He feels the most-obvious benefits of these that resistant starches are sensory qualities: the smooth texture, the very white color and the neutral taste.
The company’s wheat-based resistant starch is 70% dietary fiber, and its potato-based product has 80% dietary fiber. Compared to some other resistant starches, Ham stresses that these products have a low water-holding capacity, making them easier to incorporate into some formulas. “It helps in achieving added crispness in snack foods, baked crackers and applications where crispness is desired,” he says. “The water-holding capacities are very similar to wheat flour. It can be used at a 1:1 replacement for wheat flour.”
Usage levels depend on what the customer desires in their application. “If they’re trying to achieve, for example, a ‘good source’ of fiber or ‘excellent source’ of fiber, there are levels that need to be achieved,” Ham says. “A good source would be 2.5 grams and high source would be 5 grams per serving. Higher levels can easily be used. At higher levels, there are opportunities to add a wheat protein isolate. When replacing a high percentage of flour, which contains protein, it’s necessary to add back protein, and a wheat protein isolate is an excellent way to maintain strength in the formula and enhance processing tolerance.”
Resistant high-amylose corn starch, suggests Witwer, is widely applicable to just about any baked goods, but she notes the upper limit might depend on the application. “We know that when it was being used in low-carb foods at 70% flour replacement,” she says, “we got a loss of quality.”
Gale Gand, executive pastry chef, Tru, Chicago, and host of the Food Network show “Sweet Dreams,” was recently challenged to create desserts using National Starch’s natural highamylose resistant corn starch. “It was surprisingly easy and uneventful,” she says. “I found that I could use it instead of flour in my pastries, and it replaced wheat flour very easily. I would replace 20% to 25% of the flour in the recipe. I used it in some recipes that I would normally use corn starch to soften the wheat starch. When I made shortbread, in order to make a finer texture, I usually cut my wheat flour with a little bit of corn starch. I just used the resistant starch instead and it functioned exactly the same.”
In Gand’s experimentation, she didn’t find the ingredient’s use-level threshold. “I used a substantial amount, like 25%,” she says. “I didn’t actually find the limit of how much I could switch out. I kept going higher and higher with every recipe and I never found where the ceiling was.” She notes that when making a madeleine (a type of spongy, shell-shaped cake), she went to about 35%. “I think I could have kept going,” she suggests. “It provided a really nice, fine-textured crumb. A lot of times you might use cake flour to achieve that kind of texture, which is usually made from a softer wheat, but this way I didn’t have to have a special, different flour to get that texture. I just added the resistant starch and sort of created my own.” In effect, she used the resistant starch to “cut” the gluten level in the flour, turning an all-purpose flour to a pastry flour.
A benefit of high-amylose resistant corn starch, an RS2 starch, is that it has been widely studied from a health perspective. “It has more than 120 published studies supporting the health benefits of the ingredient,” says Witwer. It’s unclear whether other resistant starches would behave the same. “Until those studies are completed and published in journals, it’s a question,” she continues. “The resistant wheat starch would work in applications where they’re just looking for a fiber-content claim, but would not be able to make assertions or benefit statements beyond that until the work’s done.”
Products containing high-amylose resistant corn starch might provide five health benefits. The first centers on glycemic management. Energy management is the basis for the second benefit. The third one is on weight management. The fourth benefit relates to digestive health, colonic health. The fifth benefit focuses on tolerance. “We’ve shown in people in numerous trials, you can eat a lot of natural high-amylose resistant corn starch without getting digestive side effects, because it’s basically insoluble fiber and it is fermented slowly,” Witwer says.
Consumers are learning the differences between the quality of carbohydrates in their diet, suggests Witwer. “They’re looking for positive benefits such as whole grain, such as reduced glycemic, such as blood-sugar management and energy management and digestive health,” she says. “They can choose the carbohydrate that will fit in for their nutritional needs.”
From a public-health perspective, we want to be able to help deliver functional bakery products that people will want to buy. The answer to that might not be putting high fiber on the front banner of that baked good. In a lot of populations, an energy claim or a blood-sugar claim might prove more appealing to consumers. We’ve got to meet consumers where they are in language that they understand. If fiber becomes the nutritional fact that delivers the benefit and is the emotional hook for consumers, then that’s where the greatest opportunity lies.
The answer, according to Witwer, is the combination: “It’s the fiber claim. It’s the tolerance. It’s the health benefits. It’s the taste impact. You’ve got to have all of it together to really maximize the opportunity.”
Thankfully, the food industry has available a number of ingredients to meet the challenge of adding fiber to baked goods. If the finished products appeal to consumers, perhaps even satisfy a sweet tooth, health advocates might no longer feel the need to encourage consumers to get enough fiber in their diets.
Cindy Hazen, a 20-year veteran of the food industry, is a freelance writer based in Memphis, TN. She can be reached at [email protected].
Cindy Hazen has more than 25 years of experience developing seasonings, dry blends, beverages and more. Today, when not writing or consulting, she expands her knowledge of food safety as a food safety officer for a Memphis-based produce distributor.
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