Determinacion De Polisacaridos No Amilaceos A Traves De Gcl, Hplc Y Espectofotometria

View Article Online / Journal Homepage / Table of Contents for this issue

A nalyst, July 1994, Vol. 119

1497

Downloaded on 17 December 2012
Published on 01 January 1994 on http://pubs.rsc.org | doi:10.1039/AN9941901497

Determination of Dietary Fibre as Non-starch
Polysaccharides With Gas-Liquid
Chromatographic, High-performance Liquid
Chromatographic or SpectrophotometricMeasurement of Constituent Sugars

Hans N. Englyst, Michael E. Quigley and Geoffrey J. Hudson
Medical Research Council, D unn Clinical Nutrition Centre, Adden brookes
Hospital Site, Hills Road, Cambridge, U K
Methods for the measurement of dietary fibre as non-starch
polysaccharides (NSP) are described. A common enzymic
removal of starch and acid hydrolysis of the NSP to their
constituent sugarsare followed by one of three alternative
techniques, gas-liquid chromatography, high-performance
liquid chromatography or spectrophotometry, for
measurement of the released sugars. The results obtained by
the three methods are in good agreement for a wide range of
raw and processed foods. NSP compose approximately 90%
of the plant cell-wall material and are therefore a good index
of thismaterial. Values for NSP therefore provide a good
marker for a diet rich in fruit, vegetables and highextraction cereal products associated with health and
recommended in dietary guidelines. Values for total, soluble
and insoluble NSP may be obtained with any of the endpoint techniques, and the detailed information obtained from
the chromatographic methods is usehl in studies of therelationship between the intakes of various types of NSP and
health. The causes of some potential interferences in the
spectrophotometric assay, especially from processed foods,
have been identified and eliminated. The rapid
spectrophotometric version is suitable for food labelling
purposes and for quality control, and the changes described
have made it more robust.
Key words: N on -starch polysaccharide; gas-liq uid
chromatography;high-perf0 rmance liquid chromatography;
spectrophotometry; neutral sugar

Introduction
The original dietary fibre hypothesis was simply that eating a
diet rich in unrefined plant foods was protective against a
range of diseases that were common in Western societies,
where much of the ‘dietary fibre’ was removed by food
refining techniques. Over the years,a large body of evidence
has accumulated that tends to support the hypothesis.1 It is
now clear that the component of the diet for which the term
‘dietary fibre’ was coined is largely plant cell-wall material,
and that the several physiological effects of eating this material
depend on both its chemical identity and its physical structure.
This does not lead easily to a definition that willallow direct
quantification by analysis. However, recognition that the
majority (approximately 90%2) of the plant cell-wall material
in human foods can be defined chemically as non-starch
polysaccharides offers a solution. Plant foods contain a wide
variety of polysaccharides (polymers of sugars joined by
glycosidic linkages), which may be separated into two groups
on the basis of bothstructure and function. The starches are
storage polysaccharides and are chemically identifiable as

polymers of glucose with a-glucosidic linkages. The remainder, which contain no a-glucosidic linkages, are mostly
structural components of the plant cell walls, and may be
referred to conveniently as the non-starch polysaccharides
(NSP). The direct measurement of NSP in plant foods thusprovides a good index of the plant cell-wall material present in
the food. Dietary fibre measured as NSP provides useful
values for food labelling, because NSP are markers for the
type of diet rich in fruit, vegetables and high-extraction cereal
products advocated in dietary guidelines, thus providing the
consumer with valuable information. NSP values are obtained
by chemical analysis of a...