Also Known as Good Source of Fiber
What is High Fiber?
High fiber foods contain 5 grams or more of fiber per servings. The FDA regulates that the terms “high” may be used on the label when the food contains 20% or more of the RDI (Reference Daily Intake) or the DRV (Daily Reference Value) per reference amount customarily consumed.1
Comparatively, food with 5% Daily Value or less of dietary fiber per serving is low fiber. The Daily Value for fiber is 25 g per day based on 2,000 calories diet.2
The daily recommendation for fiber intake is 25 grams. Therefore, if an individual serving of a food product provides 5 grams or 20% of fiber for the consumer, then the product is considered high in fiber, and consequently, highly nutritious. On the other hand, if a food label denotes a product is “a good source of fiber,” the product must contain 10-19.6% of the daily value of fiber per individual serving. The 25-gram requirement of fiber intake is framed for those who consume roughly 1,800 calories per day. For individuals who consume a caloric intake of more or less than 1,800, a frame of reference posed by the United States Department of Agriculture is that for every 1,000 calories consumed, 14 grams of fiber should be consumed.
In the baking industry, whole-wheat or products containing oats are considered high in fiber. For instance, whole-wheat spaghetti contains over 6 grams of fiber and oatmeal contains 4 grams.
Dietary fiber is considered a “nutrient of public health concern” because low intakes are associated with potential health risks.2 A high intake of dietary fiber was associated with a reduced risk of colorectal cancer.3 Aune et al. (2011) found that for every 10 grams/day intake of total dietary fiber, the risk of colorectal cancer was reduced by 10% and reduces further with higher intake.3
The fiber can be non-starch polysaccharides and resistant oligosaccharides, analogous carbohydrates, and non-glucidic components:4
Non-starch polysaccharides and resistant oligosaccharides:
- Indigestible dextrins
- Resistant maltodextrins
- Resistant potato dextrins
- Synthesized carbohydrate
- Methyl cellulose
- Resistant starch
Sources of fiber for bakery products:
- Cereal and cereal byproducts: wheat, oat, barley and rice
- Non-cereal sources: nuts, pea, orange, sugar beet, peach, mongo, potato, and apple
- Commercial hydrocolloids: hydroxypropylmethylcellulose (HPMC), cellulose, gums (guar gum, locust bean gum, xanthan gum), oligosaccharides such as polydextrose and maltodextrins, and inulin
Effects of fiber on dough:4
- Increase in the water absorption of dough during mixing
- Increase in the development time and decrease in the mixing stability
- Decrease in dough development during proofing
- Change in the extensional properties i.e. decrease in dough extensibility
- Change in the viscous and elastic moduli i.e. dough becomes stiffer, or in some cases stickiness is increased
Effect of fiber on the properties of baked product:4
- Decrease loaf volume/spread ratio/height
- Affect texture (increases hardness of crumb, loss of crispiness)
- Changes appearance (color, surface properties, density)
- Affects taste
Ways to improve the quality of high fiber baked products:
- Add enzymes: alpha-amylase, xylanase: degrade cell wall polysaccharides
- Phytase: the crumb firmness is reduced in whole wheat bread by adding phytase and the effect of phytase is attributed to the activation of endogenous alpha-amylase5
- Sourdough fermentation: improve crumb texture and lower the rate of staling when bran is added, which attributes to an improved gluten network, changes in the water migration during staling, reduced starch retrogradation, and to degradation of cell wall components4
FDA regulates the nutrient content claiming for “high” in the article 21CFR101.54.1
- “21CFR101.54.” CFR – Code of Federal Regulations Title 21.
- “Dietary Fiber.” Accessdata. Fda. Gov. Food and Drug Administration, 6 June 2016.
- Aune, D., D. S. M. Chan, R. Lau, R. Vieira, D. C. Greenwood, E. Kampman, and T. Norat. “Dietary Fibre, Whole Grains, and Risk of Colorectal Cancer: Systematic Review and Dose-response Meta-analysis of Prospective Studies.” Bmj 343. Nov10 1 (2011): D6617.
- Ktenioudaki, Anastasia, and Eimear Gallagher. “Recent Advances in the Development of High-fibre Baked Products.” Trends in Food Science & Technology 28.1 (2012): 4-14.
- Haros, Mónica, Cristina M. Rosell, and Carmen Benedito. “Use of Fungal Phytase to Improve Breadmaking Performance of Whole Wheat Bread.”J. Agric. Food Chem. Journal of Agricultural and Food Chemistry 49.11 (2001): 5450-454.