title: Evaluation of methods of analysis for dietary fibre using real foods and model foods.
abstract: OBJECTIVE
  There are several rational and empirical methods for the measurement of dietary fibre and its components. A selection of these methods were evaluated by investigation of a range of real foods and model foods with added resistant starch (RS), non-starch polysaccharides (NSP) and resistant oligosaccharide (RO) ingredients.
  
  
  METHODS
  A range of rational methods were applied in determining specific carbohydrate constituents: RS, NSP and RO, including fructans. For comparison, empirical methods AOAC 991.43 (2001.03) and AOAC 2009.01 were applied, based on determination of gravimetric residues for high molecular weight and size-exclusion HPLC analysis of the ethanol filtrate for low molecular weight components.
  
  
  RESULTS
  In general there was agreement between different rational methods for the analysis of RS and fructans, though there were notable exceptions for some product types. Comparison of methods for total RS and those that only measure the RS3 fraction, from retrograded starch, indicated that RS3 was the only type present for most processed products. This also explains the similar results obtained by AOAC 991.43 (2001.03) and AOAC 2009.01, though the latter is intended to recover other RS types as well. For many products there was agreement between results obtained by rational and empirical methods, though there were exceptions and the reasons for these are discussed.
  
  
  CONCLUSIONS
  Rational and empirical methods can both be used to determine dietary fibre in most situations. The information provided by rational methods is useful in identifying the specific carbohydrate constituents present in foods and can assist in determining whether added extracted and synthesised ingredients are ones that conform to the Codex and EU dietary fibre definition.
authors.affiliation: Englyst Carbohydrates Ltd., 2 Venture Road, Southampton Science Park, Southampton SO16 7NP, UK. Klaus@englyst.co.uk
authors.forename: Klaus
authors.initials: K
authors.lastname: Englyst
authors.forename: Michael
authors.initials: M
authors.lastname: Quigley
authors.forename: Hans
authors.initials: H
authors.lastname: Englyst
authors.forename: Bhavna
authors.initials: B
authors.lastname: Parmar
authors.forename: Andrew
authors.initials: A
authors.lastname: Damant
authors.forename: Selvarani
authors.initials: S
authors.lastname: Elahi
authors.forename: Paul
authors.initials: P
authors.lastname: Lawrance
mesh_terms: D002241:Carbohydrates / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004043:Dietary Fiber / Q000032:analysis*; D005504:Food Analysis / Q000379:methods*; D008970:Molecular Weight
chemical_list: D002241:Carbohydrates; D004043:Dietary Fiber