248x Filetype PDF File size 0.45 MB Source: cdnmedia.eurofins.com
Dietary fibre: What is it and how to measure it correctly
Introduction
It is generally recognized that dietary fibre is an inulins/FOS, polydextroses, and GOS. Also
essential part of the human food. In our western resistant starch and resistant maltodextrins are
world the daily intake of dietary fibre is considered as dietary fibre and applied in food
considerably less than the recommended daily products.
intake (about 35 g). The different categories of
dietary fibre have shown to benefit amongst others A correct measurement of the dietary fibre content
diabetes, blood cholesterol levels, body weight is important for:
control (obesity) and reduction of the risk of 1. Correct labeling of the product
coronary heart disease. 2. Decisive for granting label and health
claims
Dietary fibre is strongly associated with natural 3. Erroneous to low dietary fibre content is
constituents in food. However, apart from the always accompanied with too high
dietary fibre which is naturally present in our food, energetics value of the product
nowadays also a whole range of a new generation
industrially prepared dietary fibre products are In this brochure the subdivision of dietary fibres in
commercially available. Many new products are different categories is given, the most frequently
launched with claims about their dietary fibre used analytical methods for the determination of
content and beneficial health effects. (different categories) dietary fibre are shortly
Manufacturers enrich their product with different discussed and a decision tree is presented in order
types of soluble or insoluble high molar weight to select the correct analytical method(s) for the
fibres, or low molar weight prebiotics like determination of the total dietary fibre content
DIETARY FIBRE
(DF)
High Molar Weigth Resistant Starch Low Molar Weight
(HMWDF) (RS) (LMWDF = prebiotic)
- Inulin
Insoluble HMW Soluble HMW
(IHMWDF) (SHMWDF) - Fructose oligosaccharide (FOS)
- RS 1
- Cellulose - Hydrocolloids Physical inaccessible starch
- Lignin - Carrageenan - RS2 - Galactose oligosaccharide (GOS)
- Insoluble pentosan - Gums Resistant starch granules
- Insoluble pectin - Guar - RS3 - Polydextrose
- β- glucans - Locust bean Retrograded Starch
(yeast/moulds) - Cassia - RS4 - Resistant Maltodextrin
- … - Arabic Chemically modified starch
- …
- Soluble pentosans
- Soluble pectins
- Cereal β- glucan
1 2012-10-18 revised dietary fibre testing - version 2012-05
starch are distinguished, Analytical
Dietary fibre being RS1, RS2, RS3, and
definition RS4. methods
And thirdly there is the A lot of different methods
In principle dietary fibre is category of low molar have been applied for total
a term that refers to a weight dietary fibres. All dietary fibre analyses in
group of food constituents different prebiotics belong food. Since a large
that pass through the to this group. number of different types
stomach and the small The scheme shows which of DF ingredients are
intestine undigested and typical dietary fibre nowadays available on the
reach the large intestine constituents belongs to the market. For this reason the
virtually unchanged. It is different categories. so called Prosky method
made up of indigestible Energetic value (AOAC 985.29) is not
parts of plants and is always the golden method
mainly composed of and health of choice for the
different types of non- claims measurement of total
starch polysaccharides dietary fiber analysis.
(NSP) and lignin. Dietary fibres play an
The exact definition of important role in the AOAC 2009.01
dietary fibre has been human nutrition. It has a
subject of much discussion energetic value of 2 kcal/g dietary fibre analysis
and controversy. In 2008 (8kJ/g). Erroneously too In the AOAC 2009.01
the CODEX Committee on low established dietary analysis both the total high
Nutrition and Foods for fibre contents are always molar weight dietary fibre
Special Uses updated the accompanied by (HMWDF) content,
terminology of the dietary erroneously too high including the resistant
fibre definition. The EU (calculated) carbohydrate starches RS1, RS2, RS3
adopted the definition of contents and thus with a and RS4 and the low
the CODEX Alimentarius too high energetic value of molar weight dietary fibre
with the remark that the product. (LMWDF) content are
carbohydrate polymers in Depending on the total measured and reported.
the dietary fibre should dietary fibre content and The sum of both results is
consist of at least three or its specific constituents the total dietary fibre
more monomeric units different health claims are content.
(2008/100/EC, annex II, allowed. Depending on
October 28, 2008). As the DF content, AOAC 2009.01
visualized in the above products can be
mentioned scheme, claimed with ‘source of DIETARY FIBRE
dietary fibre constituents (DF)
can be sub-divided in fibre’ or ‘high fibre’ Result 1
(EU1924/2006). Also Result 2
different categories High Molar Weight Resistant starch Low Molar Weight
depending on their molar various health claims (HMWDF) + (RS) (LMWDF )
weight and solubility. related to blood Insoluble HMW Soluble HMW
Firstly, the high molar cholesterol, bowel (IHMWDF) (SHMWDF)
function and feacal - Cellulose - Hydrocolloids - RS 1 - Inulin
weight dietary fibres which - Lignin - carrageenan Physical inaccessible starch - Fructose oligosaccharide (FOS)
bulking are already - Insoluble pentosan - gums - RS 2 - Galactose oligosaccharide (GOS)
- Insoluble pectin - guar Resistant starch granules - Polydextrose
can be subdivided again - ß-glucans - cassia - RS 3 - Resistant maltodextrin
accepted by EFSA. For (yeast/moulds) - arabic Retrograded starch - . . .
- . . . - . . . - RS4
into soluble and insoluble Chemically modified starch
this reason it is - Soluble pentosans
high molar weight dietary - Soluble pectins
- Cereal ß-glucan
fibers. Secondly resistant important to measure - . . .
starch. Four different products with the right 2 results, discriminates in HMWDF including RS, and in LMWDF
categories of resistant method.
2 2012-10-18 revised dietary fibre testing - version 2012-05
AOAC 2011.25 AOAC 985.29 / 991.43
DIETARY FIBRE DIETARY FIBRE
(DF) (DF)
High Molar Weight Result 1 Resistant starch Low Molar Weight High Molar Weight Resistant starch Low Molar Weight
(HMWDF) + (RS) (LMWDF ) Result 3 (HMWDF) (RS) (LMWDF )
Insoluble HMW Soluble HMW Insoluble HMW Soluble HMW
(IHMWDF) (SHMWDF) (IHMWDF) (SHMWDF)
Result 2 Result 1 Result 2
- Cellulose - Hydrocolloids - RS 1 - Inulin - Cellulose - Hydrocolloids - RS 1 - Inulin
- Lignin - carrageenan Physical inaccessible starch - Fructose oligosaccharide (FOS) - Lignin - carrageenan Physical inaccessible starch - Fructose oligosaccharide (FOS)
- Insoluble pentosan - gums - RS 2 - Galactose oligosaccharide (GOS) - Insoluble pentosan - gums - RS 2 - Galactose oligosaccharide (GOS)
- Insoluble pectin - guar Resistant starch granules - Polydextrose - Insoluble pectin - guar Resistant starch granules - Polydextrose
- RS 3 - RS 3
- ß-glucans - cassia Retrograded starch - Resistant maltodextrin - ß-glucans - cassia - RS 3 - Resistant maltodextrin
Retrograded starch
(yeast/moulds) - arabic - RS4 - . . . (yeast/moulds) - arabic Retrograded starch - . . .
- . . . - . . . - . . . - . . . - RS4
Chemically modified starch Chemically modified starch
- Soluble pentosans - Soluble pentosans
- Soluble pectins - Soluble pectins
- Cereal ß-glucan - Cereal ß-glucan
- . . . - . . .
3 results, discriminates in IHMWDF including RS, SHMWDF and in LMWDF 2 results, discriminates in IHMWDF, including retrograded starch RS3, and SHMWDF
AOAC 2011.25 dietary fibre. However one ingredient used in the
dietary fibre analysis should be aware that this material.
In the AOAC 2011.25, test excludes the resistant Below you will find a
which is an extended starch categories RS1, decision tree which allows
AOAC 2009.01 method, a RS2, and RS4 and the low you to choose the right
sub-division will be made molar weight DF. Only method in case of several
between 3 categories of RS3 will be incorporated in ingredients are applied in
dietary fibres, being (1) the test result. food products.
insoluble high molar The AOAC 985.29 can
weight dietary fibres Classical AOAC sometimes be used as a
(IHMWDF) including the 991.43 total dietary first result on the condition
resistant staches, (2), the fibre analysis that the product/sample
soluble high molar weight The same counts for the does not contain low molar
dietary fibre (SHMWDF), classical AOAC 991.43 weight dietary fibre
and (3) the low molar determination of the constituents.
weight dietary fibres insoluble and soluble high Some products contains
(LMWDF)or prebiotics. molar weight dietary fibre. by nature low molar weight
This method excludes dietary fibre constituents
Classical AOAC most types of the resistant as non-starch
985.29 total dietary starch dietary fibre. oligosaccharides and/or
fibre analysis inulins. In case a mixture
Decision tree of different dietary fibers is
For samples for which is present in the food sample
known that they don’t analytical methods we advise always to use
contain low molar weight Eurofins developed a AOAC 2009.01 (or AOAC
dietary fibres, it is possible decision tree for the best 2011.25).
to use the classical AOAC choice of methodology
985.29 determination of based on what is known
the total high molar weight about the dietary fiber
3 2012-10-18 revised dietary fibre testing - version 2012-05
In agreement with the new
(2008) definition of dietary
fibre, both with the AOAC
2009.01 and the AOAC
2011.25 analyses methods
for the total dietary fibre
content only the low molar
weight dietary fibre
constituent with DP3 and
higher are quantified. This
means that for example in
contrast with the dedicated
AOAC 2001.02 GOS
analyses, the DP2 GOS
constituents are not
quantified with these new
total dietary fibre methods.
And the same is valid for
the di-fructose FOS
constituents. Those will
only be quantified by the
dedicated AOAC 997.08
inulin/FOS method and not can also perform several the different prebiotics as
with the AOAC 2009.01 dedicated analyses for inulin/FOS, galactose-
and AOAC 2011.25 total specific dietary fibre and/or oligosaccharides,
dietary fibre methods. prebiotic constituents, as polydextroses and
for example: (branched) ß- resistant maltodextrins.
Other dietary fibre glucans from yeast and For most of these tests
tests moulds, linear ß-glucans dedicated product
Besides these packages from cereals (e.g. oats), information sheets are
and tests, Eurofins Food total resistant starch, and available.
4 2012-10-18 revised dietary fibre testing - version 2012-05
no reviews yet
Please Login to review.