SIST-TS CEN/TS 15731:2009

SLOVENSKI STANDARD
SIST-TS CEN/TS 15731:2009
01-januar-2009
Žito in žitni proizvodi - Skupna pšenica (Triticum aestivum L.) - Ugotavljanje
lastnosti testa z alveografom s prilagojeno hidratacijo za javno uporabo ali
preskušanje moke in preskušanje po metodologiji valjanja
Cereals and cereal products - Common wheat (Triticum aestivum L.) - Determination of
alveograph properties of dough at adapted hydration from commercial or test flours and
test milling methodology
Getreide und Getreideerzeugnisse - Weizen (Triticum aestivum L.) - Bestimmung der
Eigenschaften von Teig bei adaptierter Flüssigkeitszufuhr zu handelsüblichen Mehlen
oder Versuchsmehlen bei gleichen Versuchsmahlverfahren mittels Alveograph
Céréales et produits céréaliers - Blé tendre (Triticum aestivum L.) - Détermination des
propriétés alvéographiques d’une pâte à hydratation constante adaptée de farine
industrielle ou d’essai et méthodologie pour la mouture d’essai
Ta slovenski standard je istoveten z: CEN/TS 15731:2008
ICS:
67.060 äLWDVWURþQLFHLQSURL]YRGLL] Cereals, pulses and derived
QMLK products
SIST-TS CEN/TS 15731:2009 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TS CEN/TS 15731:2009

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SIST-TS CEN/TS 15731:2009
TECHNICAL SPECIFICATION
CEN/TS 15731
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
August 2008
ICS 67.060

English Version
Cereals and cereal products - Common wheat (Triticum
aestivum L.) - Determination of alveograph properties of dough
at adapted hydration from commercial or test flours and test
milling methodology
Céréales et produits céréaliers - Blé tendre (Triticum Getreide und Getreideerzeugnisse - Weizen (Triticum
aestivum L.) - Détermination des propriétés aestivum L.) - Bestimmung der Eigenschaften von Teig bei
alvéographiques d'une pâte à hydratation constante adaptierter Flüssigkeitszufuhr zu handelsüblichen Mehlen
adaptée de farine industrielle ou d'essai et méthodologie oder Versuchsmehlen bei gleichen Versuchsmahlverfahren
pour la mouture d'essai mittels Alveograph
This Technical Specification (CEN/TS) was approved by CEN on 9 March 2008 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15731:2008: E
worldwide for CEN national Members.

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Contents           Page
Foreword. 4
Introduction . 5
1 Scope. 6
2 Normative references. 6
3 Principle. 6
4 Reagents. 7
5 Apparatus. 7
6 Sampling. 12
7 Preparation of the wheat for test milling. 13
7.1 Cleaning the laboratory sample . 13
7.2 Test portion. 13
7.3 Determining the moisture content of wheat. 13
7.4 Wheat conditioning. 13
7.4.1 General. 13
7.4.2 Case of wheat with an initial moisture content of between 13 % and 15 %: (one-stage
moistening). 13
7.4.3 Case of wheat with a moisture content less than 13 %:( two-stage moistening). . 13
7.4.4 Wheat with a moisture content greater than 15 %: preliminary drying followed by conditioning,
as described above. 14
8 Laboratory milling. 14
8.1 General. 14
8.2 Milling procedure. 14
8.2.1 Break system. 14
8.2.2 Reduction system. 15
8.2.3 Flour homogenisation. 15
8.2.4 Storage of the flour. 15
8.3 Expression of milling results. 16
9 Preparation and Alveograph test. 16
9.1 Preliminary checks. 16
9.2 Preliminary operations. 20
9.3 Determination of flour water absorption capacity. 20
9.4 Kneading. 21
9.5 Preparation of dough test pieces. 21
9.6 Alveograph test. 23
9.7 Expression of the results of the Alveograph test at adapted hydration . 27
9.7.1 General. 27
9.7.2 Maximum pressure parameter “T”. 27
9.7.3 Average abscissa at rupture “A” . 28
9.7.4 Index of swelling “Ex”. 28
9.7.5 Elasticity index “Iec” . 28
9.7.6 “T/A” ratio. 28
9.7.7 Deformation energy “Fb”. 28
10 Test report. 29
Annex A (informative) Characteristics of the Chopin-Dubois CD1 mill. 30
A.1 Break system. 30
A.2 Reduction system. 30
A.3 Sieve material. 30
A.3.1 Post-break. 30
A.3.2 Post-reduction. 30
A.4 Milling. 31
A.5 Break performance indicator. 31
A.6 Conversion performance indicator. 31
A.7 Maintenance operations. 31
Annex B (normative) Moisture required to condition wheat. 32
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Annex C (informative) Example milling sheet .33
Annex D (informative) Calculated values of “Ex” .35
Annex E (informative) Routine maintenance instructions for the alveograph .36
E.1 Before every trial .36
E.2 Every day.36
E.3 Every week.36
E.4 Every month.36
E.5 Every year.37
Bibliography.38

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Foreword
This document (CEN/TS 15731:2008) has been prepared by Technical Committee CEN/TC 338 “Cereals and
cereal products”, the secretariat of which is held by AFNOR.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights.
CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden,
Switzerland and the United Kingdom.
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Introduction
The end-use value of wheat is determined by a number of properties that are useful in the manufacture of baked
products such as bread, rusks, biscuits, etc.
Such properties include the important viscoelastic (rheological) properties of dough formed as a result of flour
hydration and kneading. An alveograph is used to study the main parameters by subjecting a dough test piece to
biaxial extension (producing a dough bubble) at adapted hydration by inflating it with air, which is similar to the
deformation to which it is subjected during panary fermentation.
Recording the pressure generated inside the bubble throughout the deformation of the dough test piece until
rupture provides information on:
 resistance of the dough to deformation, or its strength (stiffness). It is expressed by the maximum pressure
parameter “T”;
 extensibility or the possibility of inflating the dough to form a bubble. It is expressed by the parameters of
extensibility “A” or swelling “Ex”;
 elasticity of the dough during biaxial extension. It is expressed by the elasticity index “Iec”;
 energy required to deform the dough bubble until it bursts, which is proportional to the area of the alveogram
(sum of the pressures throughout the deformation process). It is expressed by the parameter “Fb”.
It is generally accepted that the tenacity “T” and the extensibility “A” shall exceed a minimum level which can be
varied, depending on the particular end use to which the flour is to be put. The T/A ratio is a measurement of the
balance between tenacity and extensibility.
Alveographs are commonly used throughout the wheat and flour industry, for the following purposes:
 selecting and assessing different varieties of wheat and marketing batches of wheat;
 blending different batches of wheat or flour to produce a batch with given values for the alveographic criteria
(W, P and L) complying with the proportional laws of blending;
Alveographs are used both on the upstream side of the industry for marketing, selecting and assessing the different
varieties and on the downstream side throughout the baking industries (see Bibliography).

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1 Scope
This document specifies a method that uses an alveograph to determine the rheological properties of different
types of dough at adapted hydration obtained from “soft” to “hard” wheat flour (Triticum aestivum L.) produced
by industrial milling or laboratory test milling.
It describes the alveograph test and how to use a laboratory mill to produce flour in two stages:
− Stage 1: preparation of the wheat grain for milling to make it easier to separate the bran from the
endosperm (see Clause 7);
− Stage 2: the milling process itself, including the break system involving three fluted rollers, reduction of
particle size between two smooth rollers and the use of a centrifugal sieving machine to grade the
products (see Clause 8).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 712, Cereals and cereal products - Determination of moisture content - Routine reference method
ISO 7700-1, Check of the calibration of moisture meters -- Part 1: Moisture meters for cereals
3 Principle
The principle of measurement involves the evaluation, during deformation, of the behaviour of dough obtained
from a mixture of different types of flour and salt water. A dough disk is subjected to a constant air flow; at first
it withstands the pressure, then it swells into a bubble, according to its extensibility and ruptures. The change
in the dough is measured and recorded in the form of a curve called an alveogram.
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4 Reagents
Unless otherwise specified, use only reagents of recognised analytical quality, and distilled or demineralised
water, or water of equivalent purity.
4.1 Sodium chloride solution, obtained by dissolving (25 ± 0,2) g of sodium chloride in distilled water and
then making it up to 1 000 ml. This solution shall not be stored for more than 15 days and its temperature shall
be (20 ± 2)°C when used.
4.2 Refined vegetable oil, low in polyunsaturates such as peanut oil. It is possible to use olive oil if its acid
index value is less than 0,4 (determined according to EN ISO 660). Store in a dark place in a closed container
and replace regularly (every 3 months).
Alternatively, liquid paraffin (also known as “vaseline oil”), with an acid index value less than or equal to 0,05
and the lowest possible viscosity (maximum 60 mPa.s (60 cP) at 20 °C).
1)
4.3 Cold degreasing agent - optimum safety.
5 Apparatus
Common laboratory equipment, including the following:
5.1 Mechanical cleaner fitted with sieves for wheat cleaning, in accordance with the manufacturer's
requirements.
5.2 Conical or riffle sample divider.
5.3 Analytical balance accurate to 0,01 g.
5.4 50 ml glass burette graduated in 0,1 ml increments, stand-mounted.
)
2
5.5 Rotary blender for grain conditioning and flour homogenisation. It includes the following devices:
5.5.1 Constant speed stirrer.
5.5.2 Two worm screws integral with the flask, possibly via the stopper (one for wheat preparation, the other
for flour homogenisation).
5.5.3 Several wide-necked 2-litre plastic flasks.
)
3
5.6 Test mill (laboratory mill) manually operated (see Annex A).

1)
ITECMA “Securclean ER” is an example of a suitable product available commercially. This information is given for the
convenience of users of this Technical Specification and does not constitute an endorsement by CEN of this this product.

2
) The Chopin MR 2-litre rotary mixer is an example of a suitable product available commercially. This information is given
for the convenience of users of this Technical Specification and does not constitute an endorsement by CEN of this this
product.
3
) The Chopin-Dubois CD1 test mill is an example of a suitable product available commercially. This information is given
for the convenience of users of this Technical Specification and does not constitute an endorsement by CEN of this this
product.
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5.7 Complete alveograph system (the specifications and characteristics for some of the accessories are
given in Table 1) and include the following devices:
5.7.1 Kneading machine (see Figure 1 a) for models MA 82, MA 87 and MA 95 and Figures 2 a and 3 a
for model NG, with accurate temperature control, for dough sample preparation.
5.7.2 Hydraulic Manometeror Alveolink (See Figure 1 b) for models MA 82, MA 87 and MA 95 and
Figures 2 b and 3 b for model NG, for recording the pressure curve.
4)
5.7.3 Alveograph (see Figure 1 c) for models MA 82, MA 87 and MA 95 and Figures 2 c and 3 c)for the
NG model, with accurate temperature control, for test piece biaxial deformation of the dough pieces. It has two
rest chambers, each containing five plates on which the dough test pieces can be arranged prior to
deformation.
5)
5.8 Burette, capacity 160 ml, graduated in percentages of 0,1% of moisture content .
6)
5.9 Timer .
7)
5.10 Set of planimetric scales .
5.11 System for recording the test environment conditions (temperature and relative air humidity) as
specified in 8.1 and 9.1.
5.12 Class A 1000 ml volumetric flask (Grade A).
5.13 Pipette (25ml) graduated in 0,1 ml increments.



4)
This part of ISO 5530 was based on the CHOPIN alveograph, which is the only device of this type that is currently
available. It considers models MA 82, MA 87, MA 95 and the current Alveograph NG model.
5)
This burette is supplied with the apparatus.
6)
Only for MA82.
7)
The set of planimetric scales is supplied with the apparatus where an Alveolink is not included.
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Table 1 — Specifications and characteristics of the accessories required for the test

-1
60 ± 2
Rotational frequency of the kneading machine blade in seconds to the power of minus one (s ) ….

Height of sheeting guides, in millimetres (mm).………………………………………. 12,0 ± 0,1
Large diameter of the sheeting roller, in millimetres (mm).…………………………………. 40,0 ± 0,1
Small diameter of the sheeting roller, in millimetres (mm).……………………………. 33,3 ± 0,1
Inside diameter of the dough cutter, in millimetres (mm).………………………………… 46,0 ± 0,5
Diameter of the aperture created when the moving plate opens (which determines the effective
diameter of the specimen to be tested), in millimetres (mm) ………………………………………. 55,0 ± 0,1
Theoretical distance between the fixed and moving plates after clamping (equal to the thickness of the
test piece before inflation) in millimetres (mm) ………………………………………………………… 2,67 ± 0,01
Volume of air automatically injected to detach the test piece prior to inflating the bubble, in millilitres
a
18 ± 2
(ml) .
Linear speed of the periphery of the recording drum, in millimetres per second 5,5 ± 0,1
(mm/s).
b
96 ± 2
Air flow ensuring inflation in litres per hour (l/h).………………………………………………….
Rotation of the Manometer drum (from stop to stop) (s)……………………………………………… 55 ± 1
a
Some older devices are fitted with a pear-shaped rubber bulb for manual injection of the 18 ml required to detach the test piece.
b
To adjust the flow rate of the air generator used to inflate the bubble, fit the 12C nozzle to create a specified pressure drop (and obtain a
pressure corresponding to a height of 92 mm on the Manometer chart). The air flow rate is set with the standardised pressure drop to obtain a
pressure corresponding to a height of 60 mm on the Manometer chart, i.e. 96 l/h ± 2 l/h (see Figure 4 and Figure 5).

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Figure 1 a) — Kneading machine for Alveograph types MA-82, MA 87 and MA 95


Key
1 Handle A in position 2 2 Pump potentiometer
3 Air flow adjusting micrometric valve
Figure 1 b) — Manometer for Alveographs Figure 1 c) — Alveograph type MA-82, MA 87
types MA-82, MA 87 and MA 95 and MA 95

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Key
a NG type kneading machine 1 Air flow adjusting micrometric valve
b NG type integrator-recorder
c NG type alveograph (with NG type integrator-recorder)
Figure 2 — NG type Alveograph assembly with an “Alveolink” integrator-recorder
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Key
a NG type kneading machine 1 Air flow adjusting micrometric valve
b NG type recording pressure gauge
c NG type alveograph (with hydraulic recording pressure gauge)
Figure 3 - NG type Alveograph assembly with a hydraulic recording pressure gauge

6 Sampling
The wheat or flour sample provided to the laboratory should be truly representative; it shall not have been
damaged or modified during transport or storage.
Sampling is not included in the method specified in this Standard. Recommended sampling methods are given
in prEN ISO 24333 [1], EN ISO 6644 [2] and EN ISO 13690 [3].
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7 Preparation of the wheat for test milling
7.1 Cleaning the laboratory sample
Clean the laboratory sample with a mechanical cleaner (5.1). Ensure that all stones and metal fragments are
eliminated, as they would damage the rollers during the milling process. A magnetic device should be used to
remove the metal fragments.
7.2 Test portion
The test portion shall be representative of the initial wheat mass. Use the sample divider (5.2) to homogenise
and divide the laboratory sample until the mass required for test milling plus determining the moisture content
is obtained. The quantity of wheat mass for milling shall be at least 800 g.
7.3 Determining the moisture content of wheat
Determine the moisture content of the sample as specified in ISO 712, or using a rapid device whose
measurement does not differ from the reference value by more or less than 0,4 g water/ 100 g sample (see
ISO 7700-1).
7.4 Wheat conditioning
7.4.1 General
Conditioning the wheat for milling makes it easier to separate the bran from the endosperm. The target
moisture content is 16 % ± 0,5 %.
7.4.2 Case of wheat with an initial moisture content of between 13 % and 15 %: (one-stage
moistening).
Weigh (800 ± 1) g of wheat, using the balance (5.3) and pour it into the blender.
Add the required amount of water (see Table B.1 in Annex B) to the grain with the burette (5.4) directly, or
after weighing it to the nearest 0,1 g.
Immediately after adding the water, insert the stopper fitted with the worm screw provided for use with wheat
into the flask, shake vigorously for a few seconds and place on the rotary mixer (5.5).
Run the rotary mixer for 30 min ± 5 min (time required to distribute the water evenly across the surface of the
grains).
Allow the flask to rest for a period that brings the total time (shaking and resting) operations to 24 h ± 1 h.
7.4.3 Case of wheat with a moisture content less than 13 %:( two-stage moistening).
As a larger volume of water is required, divided it into two halves and add it in two stages during the
conditioning period.
Proceed as described in 7.4.2, using only half the total quantity of water required.
Shake the flask as described in 7.4 and allow it to rest for at least 6 h.
Then add the second half of the total quantity of water between hour 6 and hour 7.
After adding the second half, shake the flask again for 30 min ± 5 min, then allow it to rest for a period that
brings the total time of operations of moistening, shaking and resting to 24 h ± 1 h.
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7.4.4 Wheat with a moisture content greater than 15 %: preliminary drying followed by conditioning,
as described above.
Proceed imperatively to a drying in order to obtain a moisture content lower than 15 %.
The procedure is to spread the sample in a thin layer to optimise the exchange between the grain and the air.
Allow to dry in the open air in a dry place for at least 15 h.
Proceed to a new moisture determination (7.3).
Apply then the protocols as described in 7.4.2 or 7.4.3, depending on the new moisture content.
8 Laboratory milling
8.1 General
The test mill (5.6) shall be used with the manufacturer's settings.
The quality of the milling process depends on several factors:
- environmental conditions which allow the final moisture of the flour to be between 15,0 % and 15,8
...