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procedures. Several methods for specifically measuring resistant starch are now under evaluation, and some approaches are likely to measure that fraction resistant to the actions of the human stomach and small intestine and therefore, be suitable for application to all foods. Consideration should be given to methods that not only determine resistant starch, but also measure digestible or total starch in the same assay so that a portion of the total starch is not recovered in more than one starch fraction. Naturally occurring oligosaccharides inherent in foods containing Dietary Fiber need to be captured during analysis. Since most oligosaccharides are not recovered by ethanol precipitation, it may be necessary to recover them from the ethanol soluble fraction on the basis of molecular weight by chromatography or dialysis.

Current fiber analysis methods recover animal polysaccharides as dietary fiber. Thus, for those foods containing any animal carbohydrates, methods for their analysis are needed so they can be subtracted from the Dietary Fiber value. A general method applicable to all animal carbohydrates that would distinguish them from plant carbohydrates is difficult to envision. For those Dietary Fibers containing animal carbohydrates, however, it may be possible to use specific enzymatic steps to hydrolyze glycosaminoglycans (i.e., mucopolysaccharides), glycoproteins, or other carbohydrates in cartilage for subsequent quantitation. Perhaps an amount of animal-derived carbohydrates in Dietary Fiber could be defined below which the animal carbohydrate could be disregarded. For example, if 10 percent or less of the Dietary Fiber were from animals, it would not have to be determined and subtracted from the Dietary Fiber.

Some possible approaches for analyzing for Dietary Fiber that utilize unmodified current methods of analysis include:

  • a. Using gravimetric methods:
  • 1. gravimetric methods (AOAC methods 985.29, 991.43, 992.16, 993.21)
  • 2. subtract resistant starch
  • 3. subtract nondigestible, animal-derived carbohydrate
  • 4. add naturally occurring resistant starch
  • 5. add naturally occurring oligosaccharides
  • b. Using the method of Theander:
  • 1. method of Theander
  • 2. subtract resistant starch
  • 3. subtract nondigestible, animal-derived carbohydrate
  • 4. add naturally occurring resistant starch
  • 5. add naturally occurring oligosaccharides


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