All prebiotics are not created equal. Origin and structure will affect fermentability by a given group of bugs. These differences can also yield additional health benefits, including improved mineral absorption and immune system function, increased resistance to infec-tion, and reduced risk factors for colorectal diseases.
Thermal polymerization of glucose yields polydextrose, an oligosaccharide (a chain of sugar molecules ranging from 3 to 10 units in length) often utilized to provide bulk, especially in reduced-fat and lower-sugar formulations. Partial hydrolysis in the small intestines yields low-molecular-weight polydextrose fragments, which probiotic organisms ferment into disease-fighting SCFAs such as acetate, butyrate and isobutyrate.
Bugs do not live by glucose alone, though. Exclusive enzymatic processing of lactose transforms individual sugar units into galacto-oligosaccharides (GOS), notes Sarah Staley, vice president, business development, Friesland Foods Domo USA Inc., Chicago. One uniquely processed GOS provides prebiotic benefits in a sturdy form that “requires no special handling,” she says. “It is extremely heat- and acid-stable, unlike many prebiotics, which can be prone to breaking down on exposure to heat and low pH.”
Staley notes that this specialized GOS, available in both syrup and powder forms, can be used in a variety of applications. “It is extremely versatile and can handle harsh processing conditions,” she says. “Globally, GOS is often used in infant formula due to its simi-larity to human-milk oligosaccharides, as well as dairy products, juice and juice drinks, bars, and dietary supplements.”
Powdered corn starch provides the starting material for digestion-resistant maltodextrin. According to Allan Buck, director of research and development, food ingredient research, ADM, Decatur, IL, one unique form of maltodextrin is over 90% soluble dietary fiber that escapes digestion in the small intestine and is available for utilization by intestinal bacteria in the large intestine. “Although it is functionally and structurally maltodextrin, the linkages are not broken down by our digestive enzyme,” he says.
Resistant maltodextrin has been shown to be a versatile option for increasing fiber content in an array of applications, including all types of beverages, cultured dairy products, frozen dairy desserts, confections, baked goods and other processed foods. “It is highly soluble, with high clarity and low viscosity, and stability to high-temperature processing, even at low pH,” Buck adds. “This makes it ideal for clear, fortified beverages.”