1. Introduction
The definitions of dietary fibre adopted by Codex and EU include
resistant carbohydrates naturally occurring in products and
have the potential to include a range of extracted and synthesised
resistant carbohydrate ingredients (FAO/WHO, 1985/2011; EU,
2008). In terms of dietary fibre analysis, two distinct approaches
are possible, applying either rational methods that tend to determine
specific components as their monosaccharide constituents
after hydrolysis, or empirical methods that measure unspecified
intact components as a gravimetric residue and by size exclusion
HPLC (Englyst, Liu, & Englyst, 2007; AOAC, 2011). Within each of
these approaches there are further options for the selection of
methods that differ in what they measure and in their applicability.
There is a lack of information on how different analytical methods
for determination of dietary fiber and its components compare.
This has been addressed by the present study where a range of
challenging test products were selected and prepared, which included
products with added RS, RO and NSP ingredients. These
were used to evaluate a selection of methods, including their
recovery of the added ingredients and a comparison of the dietary
fiber values obtained by the analytical approaches using rational
and empirical methods.