Fiber with a cause
October 1, 2008
Thanks to advancements in carbohydrate chemistry, boosting the fiber content of grain-based foods has never been easier. But what if dietary fiber ingredients provided more than just fiber? Well, today a number of such value-added options are available to commercial bakers.
FIBER 101.Dietary fiber has traditionally been described as the portion of edible plant foods that humans lack the enzymes to digest and absorb. The two most well-known types of such fiber are referred to as soluble and insoluble. Instead of entering the bloodstream, these two fibers pass through the body and contribute no calories.
Insoluble fiber passes through the intestines largely intact as bulk. Thus, it has earned itself a reputation as being a gastrointestinal regulator. By increasing stool volume and aiding normal bowel contractions, insoluble fiber promotes regularity, reduces constipation and removes toxic wastes from the digestive system.
Soluble fiber functions somewhat differently because it has the ability to absorb water. When doing so, it is able to trap fats, cholesterol, dietary sugars and bile to slow their absorption by the digestive tract and carry them out of the body as waste. Further, soluble fibers are often fermented by bacteria in the large intestine, which assists in promoting intestinal health. Such fibers are said to exert a prebiotic effect.
OPTIONS FOR BAKERS. Bakers looking for more than simply soluble or insoluble fiber ingredients will be interested to know that it is now possible to create a point of differentiation in the crowded “fiber enriched” marketplace. Because consumers are more educated and more discerning when it comes to choosing better-for-you foods, it is the ideal time to formulate with a specialty fiber that does more than just add fiber grams to the Nutrition Facts panel.
ADM, Decatur, IL, recently introduced a line of natural bean powders that contribute not only fiber but also protein. They are made from cooked, ground black, red, navy and pinto beans. According to the company, these bean powders can be added to baked foods without af- fecting taste or texture.
The bean powders provide a convenient way for bakers to take advantage of the many nutritional benefits of beans. Indeed, beans are the only food to appear twice on the USDA Food Guide Pyramid, in both the “meat and bean” and “vegetable” categories. When incorporated into formulations, the bean powders not only provide a source of protein and fiber but can also add up to a full serving of vegetables, even in sandwich bread and grainbased snack items.
Working with beans as food ingredients has historically been quite challenging. Beans must be soaked and cooked for hours before they can be used, which require food manufacturers to invest in time and expensive equipment. ADM’s bean ingredients, on the other hand, come ready-to-use. They are prewashed, soaked and cooked and can be reconstituted in just five minutes with a product yield comparable to other bean products.
Therefore, food manufacturers who typically would not have been able to use beans because of time and expense can now easily incorporate them into many formulations.
In baked foods, the bean powders can replace 10 to 30% of the flour in a formula on a 1:1 basis. In extruded snack foods, replacement levels can be 20 to 40% of the flour. Bean powders contain slightly less moisture (9.5%) than most flours, so additional water and dough retention time may be needed.
ConAgra Mills, Omaha, NE, markets all-natural identity-preserved barley in whole-grain flour, flake and kernel forms. The ingredients have about three times the total dietary fiber and beta-glucan soluble fiber of conventional whole oats and less than half the starch of other cereal grains. “Our barley can be formulated into a wide variety of foods, including breads, tortillas, muffins, bars, crackers, cookies, for its higher fiber content and flavorful wholesome appeal,” said Elizabeth Arndt, manager of research and development, ConAgra Mills.
The Food and Drug Administration (FDA) has approved a health claim for foods providing beta-glucan soluble fiber from barley based on clinical evidence indicating a reduction in coronary heart disease risk. To qualify for the health claim, the barley-containing food must provide at least 0.75 g of beta-glucan soluble fiber and meet other claim criteria.
An example of the health claim that may be used is: “Soluble fiber from foods such as [name of food], as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. A serving of [name of food] supplies [x] grams of the soluble fiber necessary per day to have this effect.”
Beyond heart health, the higher fiber whole-grain barley ingredient can help maintain digestive health and provides satiety. Further, it can help with blood sugar management, because this barley ingredient is one of the lowest glycemic index grains available to commercial bakers.
The original health claim associating beta-glucan soluble fiber with improved cardiovascular health was limited to oat bran, rolled oats/oatmeal, whole oat flour and psyllium seed husk. Oat ingredients continue to be a value-added source of dietary fiber.
For example, Natraceutical Canada, Edmonton, AB, markets a fiber ingredient derived from oat grain. This ingredient provides the highest-quality concentrated source of soluble fiber available to commercial bakers, according to the company. Made using a gentle production process developed by scientists at the University of Alberta, Canada, the ingredient retains its natural qualities while delivering up to 12 times the soluble fiber found in a similar amount of oat bran. It takes four bowls of oatmeal to meet the FDA recommended daily intake of fiber provided by only 6 g of this ingredient.
Its production involves a patented extraction method. Enzymes and alcohol washes extract starch and protein while leaving the soluble fiber intact within the cell walls. This preserves its viscosity and ensures its effectiveness. Clinical trials have shown that the higher the soluble fiber content in a food product, the easier it is to achieve the health benefits, which include binding dietary cholesterol, providing sustained energy, prolonging the emptying of the stomach so that one feels full longer and slowing the absorption of glucose to help avoid spiking blood sugar.
Although no health claim is specifically associated with corn or corn-based ingredients, it still makes an attractive fiber ingredient option for baked foods, because certain corn ingredients can provide desirable color, flavor and texture. A corn bran ingredient from Grain Processing Corp., Muscatine, IA, is finely milled 100% natural yellow corn. It contains a minimum of 75% dietary fiber and is heat treated for stability.
“Since the ingredient is goldenbrown in color, it works best in applications that have a similar color profile such as grain-based snacks, baked goods and nutrition bars,” said Tonya Armstrong, senior applications scientist. “In these applications, the corn bran ingredient can be added from 5 to 15% without affecting the flavor or texture of the product.
“When added to a snack or baked food, the corn bran performs well in the oven and in the fryer,” Ms. Armstrong continued. “For example, in a fried snack such as tortilla chips, the addition of this corn bran ingredient helps improve structure and crunchiness. In tortilla chip formulations, 5 to 7% of corn bran can be added, which equates to about 5 g per 30-g serving. In baked foods such as an oatmeal breakfast cookie, adding 4 to 7% will ensure a good source of fiber at 4 g per 55-g serving, while maintaining a clean flavor profile and a smooth mouthfeel.”
“With interest in whole grains quickly growing, many commercial bakeries are exploring unique grain combinations to optimize the appeal, nutritional profile, functionality and sensory properties of their baked foods,” Ms. Arndt added. To assist, ConAgra Mills now offers a collection of ancient grains. The line of wholegrain ingredients includes flours, multigrain blends and eye-catching seed inclusions combining amaranth, millet, quinoa, sorghum and teff. As with the mainstream grains, these grains also provide fiber, protein, vitamins, minerals and phytonutrients but with an appealing exotic twist.”
STARCH AS FIBER. Although soluble and insoluble fibers may be the most commonly known fiber ingredients, resistant starch, a third class of dietary fiber, is gaining recognition in the food formulating world ... and with consumers.
Like soluble and insoluble fibers, resistant starch escapes digestion in the small intestine. Interestingly, resistant starch provides some of the health benefits of both soluble and insoluble fibers. For example, resistant starch is insoluble, yet it functions like a soluble prebiotic fiber, because bacteria in the large intestine can ferment it. Unlike soluble and insoluble fibers, resistant starch’s fermentation has been shown to improve metabolism.
National Starch Food Innovation, Bridgewater, NJ, markets a line of natural resistant starches that enable food formulators to create high-fiber baked foods and grain-based snacks. There are a number of types of resistant starches such as a natural granular form. National Starch offers such an ingredient based on high-amylose corn hybrids produced through traditional plant breeding. A mild heat/moisture treatment helps to align the amylose chains within the natural starch granule.
“Numerous studies have demonstrated that natural granular resistant starches derived from high-amylose corn promote intestinal/colonic health through their fermentation and action as prebiotic fibers,” said Rhonda Witwer, senior business development manager, nutrition, National Starch. “They encourage the growth of healthpromoting bacteria, reduce pH and increase the production of butyrate via fermentation. This fermentation is believed responsible for increased fat burning, decreased insulin sensitivity, increased satiety as well as improved colonic health. Research has not confirmed if other sources of resistant starch contribute similar benefits.”
Unlike soluble and insoluble fiber, resistant starch does contribute some calories. The energy value is 2 to 3 Cal per g, depending on an individual’s metabolism. By comparison, digestible starch such as flour delivers 4 Cal per g. However, consumers may not see “resistant starch” on food ingredient lists. Different types of resistant starch are labeled in various ways as food ingredients. Some analyze as dietary fiber and are listed simply as fiber on ingredient statements. Other common descriptors are starch and corn starch.
Resistant starches have application in a range of grainbased foods including breads, cakes and snack foods. They can be used as a direct replacement for 3 to 20% of the flour in a dry mix, depending on application.
Resistant starch’s low-water-holding capacity and very-fine particle size makes it easy to incorporate into dry mixes. Further, it is process tolerant. In some applications such as breads, cakes and pastries, resistant starch can improve crumb characteristics, and in sheeted baked snacks and crackers, as well as extruded snacks, it increases crispiness while reducing cracking and breakage.
MGP Ingredients, Atchison, KS, has introduced a next-generation resistant starch that not only boosts the dietary fiber content of grain-based foods but, from a functional perspective, allows enhanced crispness of snacks because of its low-water-holding capacity. “Processors can add at higher levels of inclusion, as compared with some fiber ingredients, to achieve ‘excellent source of fiber’ label claims on certain grain-based snack foods,” said Steve Ham, director of marketing, MGP.
Tate & Lyle, Decatur, IL, also markets a line of resistant starches. “A typical diet in the US and Europe does not meet the daily recommended intake of fiber and this may be linked to low consumer expectations surrounding the taste and texture of high or added-fiber products,” said Harvey Chimoff, director of marketing, Tate & Lyle Americas. “Our research shows that consumers clearly understand that fiber can be good for their health. But we also know that the consumers’ eating experience must be about the product they’ve chosen not the fiber that’s in it.”
Resistant starch is well-tolerated and has a low glycemic response. In fried foods, it has the added benefit of reducing oil pickup by 15 to 20%, which means fewer calories and less fat in the end product, according to the company.
Fiber ingredients do so much more than contribute fiber grams to the Nutrition Facts of grain-based foods. They can add protein, aid digestion, assist with satiety and improve metabolism. And today’s dietary fiber ingredients make it easier than ever to increase the fiber content in baked foods and snacks.