By Kimberly J. Decker, Contributing Editor
Our understanding of the chemistry, physics and behavior of fiber has advanced considerably over the years. “Fiber is much more than what you think it is,” says Rajen Mehta, director of fiber applications, SunOpta Ingredients Group, Chelmsford, MA. Far from an impediment to successful product development—a limiting factor to design around—today’s fibers not only promise recognized and marketable health benefits, but function, too.
Chicory root fiber is a label-friendly term for the fructo-oligosaccharide inulin. Extracted from foods like chicory, garlic, onion, agave and Jerusalem artichoke, inulin is something of a grab-bag term for a whole host of fructose polymers, which can range in size from thousands of fructose units down to fewer than a dozen, as is the case with the subgroup of inulin known as oligofructose. It’s easy to work with, inconspicuous in taste and texture, and a nutritional multitasker, with a soluble-fiber content of roughly 90 to 92 grams per 100 grams, according to Mar Nieto, Ph.D., senior principal scientist, TIC Gums, White Marsh, MD.
“Probably 60% to 70% of all the fiber fortification today is around inulin,” says Bill Bonner, senior vice president, R&D and technical sales, 21st Century Grain Processing, Kansas City, MO, whether an inulin syrup, powder or an expanded, crisped piece of inulin.
“The functionality and versatility of low-viscosity soluble fibers such as inulin has been instrumental in continuing to meet consumer demand,” says Wade Schmelzer, principle food scientist, Cargill Health & Nutrition, Minneapolis. “Inulin has also been known in the scientific arena as a prebiotic for many years. Prebiotics are beneficial for digestive health, but this benefit has not been effectively communicated to consumers in the past. This offers manufacturers the potential to differentiate their products from the competition and leverage more than just a fiber claim.”
Isomalto-oligosaccharide (IMO) shares some functionality with fructo-oligosaccharides, particularly its prebiotic effect and low calorie level (1.5 kcal per gram), but it has distinct differences. Inulin is a long-chain polysaccharide and “oligofructane consists of long chains of fructose units, having sweet taste up to 10% compared to that of sucrose/sugar,” explains Bruce Howe, CEO/president, Select Ingredients, San Diego. “However, the short-chain version available in market is FOS, which has 2 to 4 glucose units and sweetness of 30% to 50%. The maximum tolerable use per day is 15 grams. IMO is a short-chain oligosaccharide and oligoglucane, consisting of short chains of glucose units, which are linked through a specific alpha 1-6 linkage, that confer many functional and physiological health properties to the molecule. IMO is about 50% to 60% sweet compared to sucrose. The maximum tolerable use per day is about 45 grams without any adverse effect.”
The level that effectively provides prebiotic advantages is 8 to10 grams per serving, according to Howe—a level that should not adversely affect finished-product viscosity or moisture. In addition to prebiotic prowess, he notes, IMO increases intestinal mineral absorption and regulates bowel movement to relieve constipation.