Fiber closes the dietary deficit
May 1, 2013
by Donna Berry
Seldom does a day pass without hearing about the country’s budget deficit. Unfortunately, the average person has very little influence on how to rectify the financial shortfall. There is, however, another deficit dilemma in which Americans can take an active role — one that “minds the gap” between recommended daily intakes of fiber and actual consumption.
In 2002, the Institute of Medicine (IOM) established an Adequate Intake (AI) level for fiber as part of its Dietary Reference Intake recommendations for macronutrients. AIs for total fiber are based on amounts that have been observed to protect against heart disease. IOM recommended that people of all ages consume 14 g of fiber for every 1,000 Cal. This translates into varying levels of fiber based on recommended daily caloric intakes.
What good are recommended intakes if most Americans do not even come close to meeting them? This is why the 2010 Dietary Guidelines for Americans identified fiber as one of four “nutrients of concern” in the American diet; current intakes are low enough to be a public health issue.
Filling this gap is a challenge because Americans consume too many calories already. It’s not realistic to tell them simply to eat more foods inherently rich in dietary fiber. Instead, fortify the foods they already eat — and like — with fiber.
Grain fibers’ healthful halo
Formulators can select from more than 50 different fiber food ingredients, according to the recently released report “Fiber Food Ingredients in the US: Soluble, Insoluble, and Digestive-Resistant Types, 2nd ed.” from Packaged Facts, Rockville, MD.
“The introduction of some fiber food ingredients, specifically many of those categorized as novel, has allowed the development of entire new categories of fiber-enriched foods, which is helping drive the growth of specific fiber food ingredients,” said David Sprinkle, the company’s research director. “The strongest trend is with boosting the fiber content of grain-based foods, in particular those marketed as ‘made with whole grains.’ ”
Kati Ledbetter, product development scientist, ADM, Decatur, IL, suggested there has been a push during the past several years to educate consumers to choose products that contain whole grains and are a decent source of fiber. “Bakers need to understand that not all whole grains are equivalent in fiber content,” she noted. “Fortification is sometimes necessary to increase the overall fiber content of the finished product in order to make a content claim.”
Fiber food ingredients are isolated from many plants, including grains such as corn and wheat. Adding grain-based fibers to grain-based foods makes sense to both formulators and consumers.
“Label friendliness is always a consideration,” said Jeff Casper, R&D manager, Horizon Milling, Minneapolis. “Some consumers are wary of ingredients that suggest they are derived from paper or wood. There are consumer activist websites that actually use verbiage to that effect.”
Grain-based fibers impart a healthful halo effect to grain-based foods, complementing consumers’ desire for whole grains and natural products, according to Shawn Sprankle, senior food scientist, technical services, Tate & Lyle, Hoffman Estates, IL. “Many grain-based fibers not only add fiber to the product formulation, but they also help reduce calories and sugars, both of which are very desirable functions in today’s baked foods industry,” he explained.
Bakers adopt grain-based fibers for numerous reasons, said Rhonda Witwer, senior business development manager, nutrition, Ingredion, Westchester, IL. “Some bakers add grain-based fibers for their specific health benefits, whereas others want to boost total fiber content in order to make a content claim,” she observed. “Sometimes it is for both reasons.”
Offering optimal options
Because most baked foods contain grains, bakers need to rely on fibers that are compatible from a taste and functionality consideration, advised Carl Jaundoo, PhD, senior applications specialist, Roquette America Inc., Geneva, IL. “We offer soluble fibers isolated from non-genetically modified corn or wheat. Classified as dextrins, they are obtained by rearranging some of the linkages from the traditional alpha 1-4 and alpha 1-6 linkages of glucose polymers to include non-digestible linkages,” he said. “The dextrins produced are refined, purified and dried. The result is an agglomerated soluble dextrin with high dietary fiber and very low sugars content.”
The composition of the fiber ingredient is approximately 85% soluble fiber with digestible carbohydrates, protein, fats and minerals accounting for the remaining constituents. It has an energy value of 2.1 Cal per g.
Label declaration options include dextrin, resistant dextrin and, depending on the origin, soluble corn fiber or soluble wheat fiber.
“The small amount of reducing sugars in this soluble fiber ingredient contributes to the desirable browning reaction in sugar-free baked foods while still allowing a sugar-free claim,” Dr. Jaundoo said.
Ingredion uses a proprietary hybrid of identity-preserved, high-amylose corn to manufacture two grain-based fiber ingredients. Whole grain corn flour, which comes in three different particle sizes, will meet customers’ varying application needs. “The corn undergoes a live steam treatment to disable the naturally occurring enzymes that cause rancidity, enabling a nine-month shelf life,” Ms. Witwer explained. “The resulting flour is yellow, much like corn, and has a corn flavor that blends well into multi-grain foods. It contributes about 2.7 Cal per g.”
Ingredion’s second grain-based fiber ingredient is resistant starch, made from cornstarch extracted from high-amylose corn using a traditional wet-milling process. “It then undergoes proprietary physical treatment that helps align the long, linear amylose chains within the starch granule,” Ms. Witwer said.
This increases the dietary fiber content (as measured by AOAC 991.43) from less than 20% to a minimum of 54%. This resistant starch contains less than 1% fat and less than 1% protein. “It easily replaces up to 20% of the flour in baked foods, depending on the specific formulation, with minimal impact on taste or texture,” Ms. Witwer said. “Thus, it enables the development of high-fiber white bread that is still white in color and high-fiber baked foods that still look and taste like unfortified baked foods.”
Bakers can use resistant starch in breads, cookies, muffins, crackers, cakes and other snacks. Its functionality is similar to flour without significantly changing the taste or texture of the baked product, according to Ms. Witwer. “And its water-holding capacity is only slightly more than flour, making its impact on dough minimal,” she added. “A new sensory study published in the March issue of Food Science & Nutrition demonstrates that RS2 resistant starch from high-amylose corn increased the dietary fiber content of muffins and focaccia bread with minimal impact on sensory characteristics.”
The ingredient is labeled as resistant cornstarch, cornstarch or insoluble corn fiber. In the US market, it is recognized as contributing 1.4 Cal per g.
Usage rates depend upon the desired labeling claims. Some bakers use Ingredion’s whole grain corn flour and RS2 resistant starch to boost the fiber and whole grain content to qualify for a nutrient content labeling claim, while others deliver higher quantities of RS2 resistant starch in order to communicate its specific health benefits.
“Generally, if a product serving contains 9 g of RS2 resistant starch, which provides 5 g of dietary fiber, structure/function labeling claims backed with substantial clinical evidence, such as ‘promotes energy balance,’ ‘helps maintain healthy blood sugar levels in healthy individuals,’ ‘supports a healthy weight’ and ‘promotes digestive health’ can be made,” she explained. “These innovative labeling claims help attract customers who may be otherwise worried about the health impact of carbohydrates.”
Don’t forget the wheat
MGP Ingredients, Inc., Atchison, KS, offers two wheat-based fibers produced by patented technology from Kansas State University and licensed exclusively to MGP. “The technology involves modifying wheat starch with sodium trimetaphosphate and sodium tripolyphosphate, washing the modified starch and drying it to yield RS4 resistant wheat starch,” said Ody Maningat, PhD, MGP’s vice-president of applications technology and technical services. “One RS4 resistant wheat starch is a cook-up version, and the other is pregelatinized.”
The cook-up product is primarily used for fiber fortification and calorie reduction. The pregelatinized version provides three benefits: fiber fortification, calorie reduction and fat replacement. Both are labeled as modified wheat starch on ingredient legends. The cook-up version has a minimum of 85% total dietary fiber while the pregelatinized ingredient has a minimum of 75% total dietary fiber. They contribute 0.4 Cal and 1.1 Cal per g, respectively, as calculated from the nutritional information.
The wheat starch in MGP’s RS4 resistant starches has the same surface property, size, shape and distribution of sizes as the wheat starch in wheat flour, making it a suitable replacement for up to 20% of the wheat flour in most baked foods formulations, according to Dr. Maningat. “It also has the same water-holding capacity as wheat flour, which means that the bakery product requires little or no formulation changes with respect to water absorption, mixing time and baking time,” he said. “Both versions are white in color and, therefore, will not detract from the visual appearance of bread, cake or cookie products.”
Horizon Milling’s grain-based fiber ingredients are also sourced from wheat. Not only are they a source of insoluble fiber, but they also are a concentrated source of many important micronutrients.
“Wheat aleurone is a natural partner for baked foods, ready-to-eat breakfast cereals and extruded and baked snacks. It can be blended into any product where the nutrition of whole grains is desired but reduced caloric density is needed,” Mr. Casper said. “By replacing 20% of white flour in a standard bread recipe, it is possible to achieve a ‘good source’ of fiber claim. Interestingly, the taste and texture of the bread has improvements over standard whole wheat bread while possessing similar nutrition.”
Wheat aleurone is naturally derived from wheat bran using a proprietary process that physically separates the aleurone cells from the outer bran layers. Nothing is added during the process, according to Mr. Casper. It is declared on ingredient statements as wheat bran fraction or wheat aleurone.
Compared with standard commercial wheat bran, wheat aleurone is considerably lower in starch, Mr. Casper noted. “It is approximately 54% total dietary fiber, which comprises primarily arabinoxylans, beta-glucans and some fructans,” he said. “The protein content is 18% and is of much better quality than the protein found in gluten since it contains higher levels of the essential amino acids. Also, the phenolic content of aleurone is the primary contributor to the antioxidant potency of the wheat berry.” Betaine and choline are two unique functional food materials that can be found at high levels in wheat aleurone.”
Wheat aleurone contains about 1.5 Cal per g. It can be added as 20% of the flour in baked foods, but some adjustments for water will be needed. In breads, other adjustments may be required to maintain the desired baked volume and texture.
Until most consumers meet the recommended intake for fiber, fiber addition will remain a strong trend. “Finding fibers that have protective benefits will continue to be of interest, but the most important consideration is using the right fiber for each application so that taste and texture are not compromised,” Mr. Casper noted.
“Bakers should be adding more dietary fiber to their products to keep them relevant to the needs and preferences of today’s consumers,” Ms. Witwer advised. “The challenge is in selecting the right marketing language to communicate the most appropriate message for the brand and the specific product,” she said. “In many cases, it goes far beyond simple communication of dietary fiber content.”