By Jeanne Yacoubou, MS
VRG Research Director
An online reader at www.vrg.org recently asked us if the oligofructose and the fructooligosaccharides she noticed listed as ingredients in a few cereal bars were vegan. She also wondered what these ingredients were and what they were doing in cereal bars.
Oligofructose and fructooligosaccharides (FOS) are soluble (i.e., able to dissolve in water) dietary fibers. A definition of “fiber” developed in 2001 by the Dietary Fiber Technical Committee of the American Association of Cereal Chemists reads as follows:
“Dietary fiber is the edible parts of plants or analogous carbohydrates that are resistant to digestion and absorption in the human small intestine with complete or partial fermentation in the large intestine. Dietary fiber includes polysaccharides, oligosaccharides, lignin, and associated plant substances…”
Natural sources of soluble dietary fibers include legumes, oats, citrus fruits, apples, and root vegetables. Bananas, garlic, onions, leeks, and artichokes contain high levels of oligofructose and FOS.
Because oligofructose and FOS remain unchanged in the body until they reach the large intestine where they undergo fermentation, they act as food sources for probiotic (i.e., beneficial) microorganisms. As a result, oligofructose and FOS are considered “prebiotics.” The fermentation of oligofructose and FOS yields short-chain fatty acids which aid in digestive health by lowering the pH, making it difficult for pathogenic bacteria (E. coli and Salmonella) to survive while the “good” microorganisms continue to live. There are some studies that report that oligofructose and FOS also lead to increased calcium absorption because calcium remains soluble longer at lower pH.
Oligofructose and FOS often serve as sweeteners, replacing sugar or used in combination with soy, whey, or artificial sweeteners to reduce the bitter aftertaste sometimes associated with these ingredients. They may act as humectants (i.e., retaining moisture) to keep the foods (such as cereal bars) pliable and chewy. Because of their low caloric value, longer-chain oligofructose and FOS are also used as fat replacers in a variety of spreads and dairy beverages.
Oligofructose and FOS are linear chains (known as polymers) of fructose molecules, usually between two to ten units. Fructooligosaccharides always terminate with a glucose molecule while oligofructose most often contains only fructose molecules but may end with a glucose molecule. (Fructose and glucose are sugars. Fructose, found in fruits, vegetables, and honey, is considered the sweetest of all natural sugars.)
What oligofructose and FOS have in common is a very specific type of bonding (beta (2,1) glycosidic linkage) between individual molecules that is not broken by human enzymes or gastric juices.
A common commercial source of oligofructose and FOS is inulin, a fructose polymer, (also referred to as fructan or a polysaccharide), containing between 2 and 60 units, derived from chicory root. Longer-chained inulins work better at replacing fats (in yogurt, spreads and dressings) while shorter ones function well as sugar replacers or sweetener enhancers (in chocolate or confections). They all may be purchased as dietary supplements.
One type of oligofructose supplement is branded Orafti™ by Beneo. Chicory root is used as their starting material: http://www.beneo-orafti.com/Our-Products/Natural-Food-Ingredients Inulin is extracted from chicory root by hot water. Then inulin is split into shorter fragments of oligofructose by enzymes. Activated carbon is used to decolorize.
Beneo’s oligofructose received Generally Recognized as Safe (GRAS) status for use in infant formula by the United States Food and Drug Administration (FDA) in 2012. The document linked below details production methods. (GRAS status means an ingredient may be used in all food categories, following good manufacturing practices, with only a few exceptions).
Another company, Sensus America, received similar FDA GRAS status approval in 2002 for its inulin product derived from chicory root: http://www.accessdata.fda.gov/scripts/fcn/gras_notices/219363a.pdf
The VRG contacted other companies in August 2012 about their FOS starting materials. Source Naturals, UAS Labs, Jarrow, and Food Science of Vermont use chicory root in their FOS products.
For more on oligofructose derived from chicory root:
It is possible to create in a lab through a fermentation process short-chain fructans between two and five units long known as scFOS. These are derived from sucrose (from cane or beet sugar) and consist of fructose chains that always terminate in a glucose molecule. Of the companies that The VRG contacted in August 2012, Nutricology and American Ingredients stated that their source is sugar cane. VegLife (under Solaray) told us “sugar” but could not be more specific. NOW Foods said “sucrose.”
Interested readers may note that cane sugar and sugar beets are the two leading sources of sucrose (table sugar). The large majority of sugar produced globally is derived from sugar cane. As The VRG reported in 2007, most cane sugar is decolorized using cow bone char filter. http://www.vrg.org/journal/vj2007issue4/2007_issue4_sugar.php
Readers who wish to learn more about inulin, oligofructose, and fructooligosaccharides may view:
The contents of this article, our website, and our other publications, including The Vegetarian Journal, are not intended to provide personal medical advice. Medical advice should be obtained from a qualified health professional. We often depend on product and ingredient information from company employees or company statements. Information does change and mistakes are always possible. Please use your own best judgment about whether a product is suitable for you. Further research or confirmation may be warranted.
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