SIST EN ISO 27971:2015

Cereals and cereal products - Common wheat (Triticum aestivum L.) - Determination of alveograph properties of dough at constant hydration from commercial or test flours and test milling methodology (ISO 27971:2015)

This International Standard specifies a method of determining, using an alveograph, the rheological
properties of different types of dough obtained from common wheat flour (Triticum aestivum L.)
produced by industrial milling or laboratory 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, including breaking between 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).

Getreide und Getreideerzeugnisse - Weizen (Triticum aestivum L.) - Bestimmung der Eigenschaften von Teig bei konstanter Flüssigkeitszufuhr zu handelsüblichen Mehlen oder Versuchsmehlen bei gleichen Versuchsmahlverfahren mittels Alveograph (ISO 27971:2015)

Diese Internationale Norm legt ein Verfahren zur Bestimmung der rheologischen Eigenschaften verschiedener Teigarten mittels eines Alveographen fest, die aus Mehl von Weichweizen (Triticum aestivum L.) erhalten wurden, das durch industrielles Vermahlen oder Laborvermahlung hergestellt wurde.
Sie beschreibt das alveographische Prüfverfahren sowie die Art und Weise der Anwendung einer Labormühle zur Herstellung von Mehl in zwei Stufen:
-   Stufe 1: Vorbereitung des Weizens zum Vermahlen, damit die Kleie leichter vom Endosperm getrennt werden kann (siehe Abschnitt 7);
-   Stufe 2: die Vermahlung, einschließlich der Schrotung zwischen drei Riffelwalzen, der Verringerung der Korngröße zwischen zwei Glattwalzen sowie der Verwendung einer Zentrifugalsiebmaschine zur Klassierung der Erzeugnisse (siehe Abschnitt 8).

Céréales et produits céréaliers - Blé tendre (Triticum aestivum L.) - Détermination des propriétés alvéographiques d'une pâte à hydratation constante de farine industrielle ou d'essai et méthodologie pour la mouture d'essai (ISO 27971:2015)

ISO 27971:2015 spécifie une méthode de détermination, au moyen d'un alvéographe, des caractéristiques rhéologiques de différents types de pâtes obtenues à partir de farines de blés tendres (Triticum aestivum L.) issues de mouture industrielle ou de mouture d'essai.

Žito in proizvodi iz žita - Navadna pšenica (Triticum aestivum L.) - Določevanje lastnosti testa iz običajnih komercialnih ali preskusnih mok z alveografom ob stalnem dodajanju vode in s preskusnim postopkom mletja (ISO 27971:2015)

Ta mednarodni standard določa metodo za določanje – z alveografom – reoloških lastnosti različnih tipov testa iz običajne pšenične moke (Triticum aestivum L.), pridobljene z industrijskim ali laboratorijskim mletjem.
Opisuje preskus z alveografom in kako uporabiti laboratorijski mlin za izdelavo moke v dveh korakih:
– 1. korak: priprava pšeničnega zrnja za mletje za lažje ločevanje lupine od
endosperma (glej točko 7)
– 2. korak: postopek mletja, vključno z lomljenjem med tremi rebrastimi valji, zmanjšanjem velikosti delcev med dvema gladkima valjema in uporabo centrifugalnega stroja za presejanje za razvrščanje izdelka.
(glej točko 8.)

General Information

• Status: Withdrawn
• Public Enquiry End Date: 14-Apr-2014
• Publication Date: 04-Aug-2015
• Withdrawal Date: 15-Aug-2023
• ICS: 67.060 - Cereals, pulses and derived products
• Technical Committee: KŽP - Agricultural food products
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 05-Jul-2023
• Due Date: 28-Jul-2023
• Completion Date: 16-Aug-2023
• Ref Project: EN ISO 27971:2015 - Cereals and cereal products - Common wheat (Triticum aestivum L.) - Determination of alveograph properties of dough at constant hydration from commercial or test flours and test milling methodology (ISO 27971:2015)

Relations

• Replaces: SIST EN ISO 27971:2008 - Cereals and cereal products - Common wheat (Triticum aestivum L.) - Determination of alveograph properties of dough at constant hydration from commercial or test flours and test milling methodology (ISO 27971:2008)
• Effective Date: 01-Sep-2015
• Replaced By: SIST EN ISO 27971:2023 - Cereals and cereal products - Common wheat (Triticum aestivum L.) - Determination of alveograph properties of dough at constant hydration from commercial or test flours and test milling methodology (ISO 27971:2023)
• Effective Date: 01-Sep-2023

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 27971:2015
01-september-2015
1DGRPHãþD
SIST EN ISO 27971:2008
äLWRLQSURL]YRGLL]åLWD1DYDGQDSãHQLFD7ULWLFXPDHVWLYXP/'RORþHYDQMH
ODVWQRVWLWHVWDL]RELþDMQLKNRPHUFLDOQLKDOLSUHVNXVQLKPRN]DOYHRJUDIRPRE
VWDOQHPGRGDMDQMXYRGHLQVSUHVNXVQLPSRVWRSNRPPOHWMD,62
Cereals and cereal products - Common wheat (Triticum aestivum L.) - Determination of
alveograph properties of dough at constant hydration from commercial or test flours and
test milling methodology (ISO 27971:2015)
Getreide und Getreideerzeugnisse - Weizen (Triticum aestivum L.) - Bestimmung der
Eigenschaften von Teig bei konstanter Flüssigkeitszufuhr zu handelsüblichen Mehlen
oder Versuchsmehlen bei gleichen Versuchsmahlverfahren mittels Alveograph (ISO
27971:2015)
Céréales et produits céréaliers - Blé tendre (Triticum aestivum L.) - Détermination des
propriétés alvéographiques d'une pâte à hydratation constante de farine industrielle ou
d'essai et méthodologie pour la mouture d'essai (ISO 27971:2015)
Ta slovenski standard je istoveten z: EN ISO 27971:2015
ICS:
67.060 äLWDVWURþQLFHLQSURL]YRGLL] Cereals, pulses and derived
QMLK products
SIST EN ISO 27971:2015 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 27971:2015

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SIST EN ISO 27971:2015

EUROPEAN STANDARD
EN ISO 27971

NORME EUROPÉENNE

EUROPÄISCHE NORM
June 2015
ICS 67.060 Supersedes EN ISO 27971:2008
English Version
Cereals and cereal products - Common wheat (Triticum
aestivum L.) - Determination of alveograph properties of dough
at constant hydration from commercial or test flours and test
milling methodology (ISO 27971:2015)
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 de konstanter Flüssigkeitszufuhr zu handelsüblichen Mehlen
farine industrielle ou d'essai et méthodologie pour la oder Versuchsmehlen bei gleichen Versuchsmahlverfahren
mouture d'essai (ISO 27971:2015) mittels Alveograph (ISO 27971:2015)
This European Standard was approved by CEN on 16 April 2015.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 27971:2015 E
worldwide for CEN national Members.

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SIST EN ISO 27971:2015
EN ISO 27971:2015 (E)
Contents Page
Foreword .3

2

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SIST EN ISO 27971:2015
EN ISO 27971:2015 (E)
Foreword
This document (EN ISO 27971:2015) has been prepared by Technical Committee ISO/TC 34 "Food products"
in collaboration with Technical Committee CEN/TC 338 “Cereal and cereal products” the secretariat of which
is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by December 2015, and conflicting national standards shall be withdrawn
at the latest by December 2015.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 27971:2008.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 27971:2015 has been approved by CEN as EN ISO 27971:2015 without any modification.
3

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SIST EN ISO 27971:2015

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SIST EN ISO 27971:2015
INTERNATIONAL ISO
STANDARD 27971
Second edition
2015-06-01
Cereals and cereal products —
Common wheat (Triticum
aestivum L.) — Determination of
alveograph properties of dough at
constant hydration from commercial
or test flours and test milling
methodology
Céréales et produits céréaliers — Blé tendre (Triticum aestivum
L.) — Détermination des propriétés alvéographiques d’une
pâte à hydratation constante de farine industrielle ou d’essai et
méthodologie pour la mouture d’essai
Reference number
ISO 27971:2015(E)
©
ISO 2015

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SIST EN ISO 27971:2015
ISO 27971:2015(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

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SIST EN ISO 27971:2015
ISO 27971:2015(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Principle . 1
4 Reagents . 1
5 Apparatus . 2
6 Sampling . 9
7 Preparation of the wheat for laboratory milling. .10
7.1 Cleaning the laboratory sample .10
7.2 Test portion .10
7.3 Wheat moisture content determination .10
7.4 Wheat preparation.10
7.4.1 General.10
7.4.2 Wheat with initial moisture content between 13 % and 15 % (one-
stage moistening) .10
7.4.3 Wheat with a moisture content less than 13 % (two-stage moistening) . .10
7.4.4 Wheat with a moisture content greater than 15 % (preliminary drying
followed by moistening, as described above) .11
8 Laboratory milling .11
8.1 General .11
8.2 Milling procedure .11
8.2.1 Breaking .11
8.2.2 Reduction .11
8.2.3 Flour homogenization .12
8.2.4 Storage of the flour.12
8.3 Expression of milling results.12
9 Preparation and alveograph test .13
9.1 Preliminary checks .13
9.2 Preliminary operations .14
9.3 Kneading .15
9.4 Preparation of dough test pieces .16
9.5 Alveograph test .20
9.5.1 Initial preparation.20
9.5.2 First operation: Adjusting the dough test piece .21
9.5.3 Second operation: biaxial extension .22
9.6 Expression of alveograph test results .23
9.6.1 General.23
9.6.2 Maximum pressure parameter, P . 23
9.6.3 Mean abscissa at rupture, L . 23
9.6.4 Swelling index, G . 24
9.6.5 Elasticity index .24
9.6.6 Curve configuration ratio, P/L . 24
9.6.7 Deformation work, W . 24
10 Precision .24
10.1 Interlaboratory tests .24
10.2 Repeatability limits .25
10.2.1 Commercial flour: limits established by the interlaboratory test .25
10.2.2 Flour obtained from laboratory milling .25
10.3 Reproducibility limits .25
© ISO 2015 – All rights reserved iii

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SIST EN ISO 27971:2015
ISO 27971:2015(E)

10.3.1 Commercial flour: Limits established by the proficiency tests .25
10.3.2 Flour obtained from laboratory milling .26
10.4 Uncertainty .26
11 Test report .26
Annex A (informative) Characteristics of the Chopin-Dubois CD1 mill .27
Annex B (normative) Quantity of water to be added to wheat for conditioning.29
Annex C (informative) Sample milling sheet .31
Annex D (informative) Conversion table from L to G .32
Annex E (informative) Interlaboratory and proficiency test data for commercial flours .34
Annex F (informative) Interlaboratory data for laboratory milled flour .44
Annex G (informative) Routine maintenance instructions for the alveograph .61
Annex H (informative) Assessment of proteolytic activity in wheat (T. aestivum L.) or flour .63
Bibliography .65
iv © ISO 2015 – All rights reserved

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SIST EN ISO 27971:2015
ISO 27971:2015(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 34, Food products, Subcommittee SC 4,
Cereals and pulse.
This second edition cancels and replaces the first edition (ISO 27971:2008), which has been
technically revised.
© ISO 2015 – All rights reserved v

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SIST EN ISO 27971:2015
ISO 27971:2015(E)

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, and biscuits.
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) 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 it ruptures provides information on the following:
a) the resistance of the dough to deformation, or its strength. It is expressed by the maximum pressure
parameter, P;
b) the extensibility or the possibility of inflating the dough to form a bubble; It is expressed by the
parameters of extensibility, L, or swelling, G;
c) the elasticity of the dough during biaxial extension. It is expressed by the elasticity index, I ;
e
d) the work required to deform the dough bubble until it ruptures, which is proportional to the area
of the alveogram (sum of the pressures throughout the deformation process). It is expressed by the
parameter, W.
The P/L ratio is a measurement of the balance between strength 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 wheat varieties and on the downstream side throughout the baking industries (see
Bibliography).
vi © ISO 2015 – All rights reserved

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SIST EN ISO 27971:2015
INTERNATIONAL STANDARD ISO 27971:2015(E)
Cereals and cereal products — Common wheat (Triticum
aestivum L.) — Determination of alveograph properties of
dough at constant hydration from commercial or test flours
and test milling methodology
1 Scope
This International Standard specifies a method of determining, using an alveograph, the rheological
properties of different types of dough obtained from common wheat flour (Triticum aestivum L.)
produced by industrial milling or laboratory 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, including breaking between 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 documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 660, Animal and vegetable fats and oils — Determination of acid value and acidity
ISO 712, Cereals and cereal products — Determination of moisture content — Reference method
ISO 12099, Animal feeding stuffs, cereals and milled cereal products — Guidelines for the application of near
infrared spectrometry
3 Principle
The behaviour of dough obtained from a mixture of different types of flour and salt water is evaluated
during deformation. A dough disk is subjected to a constant air flow; at first it withstands the pressure.
Subsequently, it inflates 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.
4 Reagents
Unless otherwise specified, use only reagents of recognized analytical grade, and only distilled or
demineralized water or water of equivalent purity.
4.1 Sodium chloride solution, obtained by dissolving (25 ± 0,2) g of sodium chloride (NaCl) in water
and then making the volume up to 1 000 ml. This solution shall not be stored for more than 15 d and its
temperature shall be (20 ± 2) °C when used.
© ISO 2015 – All rights reserved 1

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SIST EN ISO 27971:2015
ISO 27971:2015(E)

4.2 Refined vegetable oil, low in polyunsaturates, such as peanut oil. It is possible to use olive oil if its
acid value is less than 0,4 (determined according to ISO 660). Store in a dark place in a closed container
and replace regularly (at least every three months).
Alternatively, liquid paraffin (also known as “soft petroleum paraffin”), with an acid value of less than
or equal to 0,05 and the lowest possible viscosity [maximum 60 mPa·s (60 cP) at 20 °C].
4.3 Cold degreasing agent, optimum safety.
5 Apparatus
Usual laboratory apparatus and, in particular, the following.
5.1 Mechanical cleaner, fitted with sieves for wheat cleaning, in accordance with the manufacturer’s
instructions.
5.2 Conical or riffle sample divider.
5.3 Analytical balance, accurate to 0,01 g.
5.4 Glass burette, of 50 ml in capacity, graduated in 1 ml divisions.
1)
5.5 Rotary blender , for grain conditioning and flour homogenization, including the following components:
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 homogenization).
5.5.3 Several wide-necked plastic flasks, 2 l capacity.
5.6 Test mill (laboratory mill), manually or automatically operated (see Annex A).
5.7 Complete alveograph system (see Table 1 for specifications and characteristics of the accessories)
including the following devices:
5.7.1 Kneading machine [for models MA 82, MA 87, and MA 95, see Figure 1 a); for model NG, see label
a in Figure 2 and Figure 3], with accurate temperature control, for dough sample preparation.
2)
5.7.2 Hydraulic manometer or Alveolink [for models MA 82, MA 87, and MA 95, see Figure 1 b); for
model NG, see label b in Figure 2 and Figure 3] for recording the pressure curve.
3)
5.7.3 Alveograph [for models MA 82, MA 87, and MA 95, see Figure 1 c); for model NG, see label
c in Figures 2 and Figure 3] with accurate temperature control, for biaxial deformation of the dough
1) The Chopin MR 2 l rotary blender is an example of a suitable product available commercially. This information
is given for the convenience of users of this International Standard and does not constitute an endorsement by ISO
of this product.
2) Alveolink is an example of a suitable product available commercially. This information is given for the
convenience of users of this International Standard and does not constitute an endorsement by ISO of this product.
3) The methods specified in this International Standard are based on the use of the MA 82, MA 87, MA 95 and NG
models of Chopin alveograph which are examples of suitable products commercially available This information is
given for the convenience of users of this International Standard and does not constitute an endorsement by ISO of
this product.
2 © ISO 2015 – All rights reserved

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SIST EN ISO 27971:2015
ISO 27971:2015(E)

test pieces. It has two rest chambers, each containing five plates on which the dough test pieces can be
arranged prior to deformation.
5.8 Burette with stopcock, supplied with the apparatus, 160 ml capacity, graduated in divisions of
0,1 % of moisture content.
NOTE Throughout this International Standard, “content” is expressed as a “mass fraction” (see ISO 80000-9,
[6]
12 ), i.e. the ratio of the mass of substance in a mixture to the total mass of the mixture.
5.9 Timer, for use with model MA 82 only.
5.10 Planimetric scales, supplied with the apparatus where an Alveolink is not included.
5.11 System for recording the test environment conditions (temperature and relative air humidity)
as specified in 8.1 and 9.1.
5.12 Volumetric flask, 1 000 ml capacity, complying with the requirements of ISO 1042, class A.
5.13 Pipette, 25 ml capacity, graduated in divisions of 0,1 ml, complying with the requirements of
ISO 835, class A.
© ISO 2015 – All rights reserved 3

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SIST EN ISO 27971:2015
ISO 27971:2015(E)

a) Kneading machine
4 © ISO 2015 – All rights reserved

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SIST EN ISO 27971:2015
ISO 27971:2015(E)

b) Manometer
© ISO 2015 – All rights reserved 5

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SIST EN ISO 27971:2015
ISO 27971:2015(E)

c) Alveograph
Key
1 handle A in position 2
2 pump potentiometer
3 micrometric valve for air flow adjustment
F
...

SLOVENSKI STANDARD
oSIST prEN ISO 27971:2014
01-marec-2014
äLWRLQSURL]YRGLL]åLWD6NXSQDSãHQLFD7ULWLFXPDHVWLYXP/'RORþHYDQMH
ODVWQRVWLWHVWDL]RELþDMQLKNRPHUFLDOQLKDOLSUHVNXVQLKPRN]DOYHRJUDIRPRE
VWDOQLKLGUDFLMLLQVSUHVNXVQLPSRVWRSNRPPOHWMD,62',6
Cereals and cereal products - Common wheat (Triticum aestivum L.) - Determination of
alveograph properties of dough at constant hydration from commercial or test flours and
test milling methodology (ISO/DIS 27971:2014)
Getreide und Getreideerzeugnisse - Weizen (Triticum aestivum L.) - Bestimmung der
Eigenschaften von Teig bei konstanter Flüssigkeitszufuhr zu handelsüblichen Mehlen
oder Versuchsmehlen bei gleichen Versuchsmahlverfahren mittels Alveograph (ISO/DIS
27971:2014)
Céréales et produits céréaliers - Blé tendre (Triticum aestivum L.) - Détermination des
propriétés alvéographiques d'une pâte à hydratation constante de farine industrielle ou
d'essai et méthodologie pour la mouture d'essai (ISO/DIS 27971:2014)
Ta slovenski standard je istoveten z: prEN ISO 27971
ICS:
67.060 äLWDVWURþQLFHLQSURL]YRGLL] Cereals, pulses and derived
QMLK products
oSIST prEN ISO 27971:2014 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 27971:2014

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oSIST prEN ISO 27971:2014
DRAFT INTERNATIONAL STANDARD
ISO/DIS 27971
ISO/TC 34/SC 4 Secretariat: SAC
Voting begins on: Voting terminates on:
2014-01-09 2014-06-09
Cereals and cereal products — Common wheat (Triticum
aestivum L.) — Determination of alveograph properties of
dough at constant hydration from commercial or test flours
and test milling methodology
Céréales et produits céréaliers — Blé tendre (Triticum aestivum L.) — Détermination des propriétés
alvéographiques d’une pâte à hydratation constante de farine industrielle ou d’essai et méthodologie pour
la mouture d’essai
[Revision of first edition (ISO 27971:2008)]
ICS: 67.060
ISO/CEN PARALLEL PROCESSING
This draft has been developed within the International Organization for
Standardization (ISO), and processed under the ISO lead mode of collaboration
as defined in the Vienna Agreement.
This draft is hereby submitted to the ISO member bodies and to the CEN member
bodies for a parallel five month enquiry.
Should this draft be accepted, a final draft, established on the basis of comments
received, will be submitted to a parallel two-month approval vote in ISO and
THIS DOCUMENT IS A DRAFT CIRCULATED
formal vote in CEN.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
To expedite distribution, this document is circulated as received from the
IN ADDITION TO THEIR EVALUATION AS
committee secretariat. ISO Central Secretariat work of editing and text
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Copyright notice
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oSIST prEN ISO 27971:2014
ISO/DIS 27971
Contents Page
Foreword. v
Introduction . vi
1 Scope. 1
2 Normative references. 1
3 Principle. 1
4 Reagents. 2
5 Apparatus. 2
6 Sampling. 3
7 Preparation of the wheat for laboratory milling. 7
7.1 Cleaning the laboratory sample . 7
7.2 Test portion . 7
7.3 Wheat moisture content determination. 7
7.4 Wheat preparation. 8
7.4.1 General. 8
7.4.2 Wheat with initial moisture content between 13 % and 15 % (one-stage moistening). 8
7.4.3 Wheat with a moisture content less than 13 % (two-stage moistening) . 9
7.4.4 Wheat with a moisture content greater than 15 % (preliminary drying followed by moistening,
as described above).9
8 Laboratory milling. 9
8.1 General. 9
8.2 Milling procedure. 10
8.2.1 Breaking. 10
8.2.2 Reduction . 10
8.2.3 Flour homogenization . 10
8.2.4 Storage of the flour. 10
8.3 Expression of milling results. 11
9 Preparation and alveograph test. 11
9.1 Preliminary checks. 11
9.2 Preliminary operations. 14
9.3 Kneading. 14
9.4 Preparation of dough test pieces. 14
9.5 Alveograph test. 17
9.5.1 Initial preparation. 17
9.5.2 First operation: adjusting the dough test piece . 17
9.5.3 Second operation: biaxial extension . 19
9.6 Expression of alveograph test results. 19
9.6.1 General. 19
9.6.2 Maximum pressure parameter, P . 19
9.6.3 Mean abscissa at rupture, L. 19
9.6.4 Swelling index, G .20
9.6.5 Elasticity index. 20
9.6.6 Curve configuration ratio, P/L . 21
9.6.7 Deformation work, W . 21
10 Precision. 21
10.1 Interlaboratory tests . 21
10.2 Repeatability limits. 22
10.2.1 Commercial flour: Limits established by the interlaboratory test. 22
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10.2.2 Flour obtained from laboratory milling. 22
10.3 Reproducibility limits. 22
10.3.1 Commercial flour: Limits established by the proficiency tests . 22
10.3.2 Flour obtained from laboratory milling. 23
10.4 Uncertainty. 23
11 Test report. 23
Annex A (informative) Characteristics of the Chopin-Dubois CD1 mill . 24
A.1 Breaking. 24
A.2 Reduction. 24
A.3 Sieve material. 24
A.3.1 Post-break. 24
A.3.2 Post-reduction. 24
A.4 Milling. 25
A.5 Break performance indicator . 25
A.6 Reduction performance indicator . 25
A.7 Maintenance operations . 25
Annex B (normative) Quantity of water to be added to wheat for conditioning . 26
Annex C (informative) Sample milling sheet. 27
Annex D (informative) Conversion table from L to G . 28
Annex E (informative) Interlaboratory and proficiency test data for commercial flours. 30
Annex F (informative) Interlaboratory data for laboratory milled flour. 35
Annex G (informative) Routine maintenance instructions for the alveograph . 48
G.1 Before every test . 48
G.2 Every day. 48
G.3 Every week. 48
G.4 Every month. 49
G.5 Every year. 49
Annex H (informative) Assessment of proteolytic activity  in wheat (T. aestivum L.) or flour . 50
H.1 General. 50
H.2 Principle. 50
H.3 Reagents. 50
H.4 Apparatus. 50
H.5 Sampling and sample preparation . 50
H.6 Preparation and alveograph test . 50
H.6.2 Expression of alveograph results . 51
Bibliography . 52

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oSIST prEN ISO 27971:2014
ISO/DIS 27971
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 27971 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 4, cereals
and pulse.
This second edition cancels and replaces the first edition, which has been technically revised.
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oSIST prEN ISO 27971:2014
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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, and biscuits.
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) 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 it
ruptures provides information on:
� the resistance of the dough to deformation, or its strength. It is expressed by the maximum pressure
parameter, P;
� the extensibility or the possibility of inflating the dough to form a bubble; It is expressed by the
parameters of extensibility, L, or swelling, G;
� the elasticity of the dough during biaxial extension. It is expressed by the elasticity index, I ;
e
� the work required to deform the dough bubble until it ruptures, which is proportional to the area of the
alveogram (sum of the pressures throughout the deformation process). It is expressed by the parameter,
W.
The P/L ratio is a measurement of the balance between strength 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 wheat varieties and on the downstream side throughout the baking industries (see Bibliography).
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oSIST prEN ISO 27971:2014
DRAFT INTERNATIONAL STANDARD ISO/DIS 27971

Cereals and cereal products — Common wheat (Triticum
aestivum L.) — Determination of alveograph properties of
dough at constant hydration from commercial or test flours and
test milling methodology
1 Scope
This International Standard specifies a method of determining, using an alveograph, the rheological properties
of different types of dough obtained from "soft" to "hard" wheat flour (Triticum aestivum L.) produced by
industrial milling or laboratory 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, including breaking between 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 385, Laboratory glassware — Burettes.
ISO 660, Animal and vegetable fats and oils — Determination of acid value and acidity.
ISO 712, Cereals and cereal products — Determination of moisture content - Reference method.
ISO 835, Laboratory glassware — Graduated pipettes.
ISO 1042, Laboratory glassware — One-mark volumetric flasks.
ISO 7700-1, Checking the performance of moisture meters in use — Part 1: Moisture meters for cereals.
3 Principle
The behaviour of dough obtained from a mixture of different types of flour and salt water is evaluated during
deformation. A dough disk is subjected to a constant air flow; at first it withstands the pressure. Subsequently,
it inflates 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 recognized analytical grade, and only distilled or
demineralized water or water of equivalent purity.
4.1 Sodium chloride solution, obtained by dissolving (25 � 0,2) g of sodium chloride (NaCl) in water and
then making the volume 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
value is less than 0,4 (determined according to ISO 660). Store in a dark place in a closed container and
replace regularly (at least every 3 months).
Alternatively, liquid paraffin (also known as "soft petroleum paraffin"), with an acid 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
Usual laboratory apparatus, and in particular the following.
5.1 Mechanical cleaner, fitted with sieves for wheat cleaning, in accordance with the manufacturer's
instructions.
5.2 Conical or riffle sample divider.
5.3 Analytical balance, accurate to 0,01 g.
5.4 Glass burette, 50 ml capacity, graduated in 0,1 ml divisions, complying with the requirements of
ISO 385, Class A, stand-mounted.
2)
5.5 Rotary blender for grain conditioning and flour homogenization, including the following components:
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 homogenization).
5.5.3 Several wide-necked plastic flasks, 2 l capacity.
3)
5.6 Test mill (laboratory mill), manually or automatically operated (see Annex A).
5.7 Complete alveograph system (see Table 1 for specifications and characteristics of the accessories)
including the following devices:

1)
ITECMA "Securclean ER" is an example of a suitable product available commercially. This information is given for the
convenience of users of this International Standard and does not constitute an endorsement by ISO of this product.
2)
The Chopin MR 2 l rotary blender is an example of a suitable product available commercially. This information is given
for the convenience of users of this International Standard and does not constitute an endorsement by ISO of 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 International Standard and does not constitute an endorsement by ISO of this product.
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5.7.1 Kneading machine [for models MA 82, MA 87 and MA 95, see Figure 1 a); for model NG, see label a
in Figure 2 and Figure 3], with accurate temperature control, for dough sample preparation.
4)
5.7.2 Hydraulic manometer or Alveolink [for models MA 82, MA 87 and MA 95, see Figure 1 b); for
model NG, see label b in Figure 2 and Figure 3] for recording the pressure curve.
5)
5.7.3 Alveograph [for models MA 82, MA 87 and MA 95, see Figure 1 c); for model NG, see label c in
Figures 2 and Figure 3] with accurate temperature control, for biaxial deformation of the dough test pieces. It
has two rest chambers, each containing five plates on which the dough test pieces can be arranged prior to
deformation.
5.8 Burette with stopcock, supplied with the apparatus, 160 ml capacity, graduated in divisions of 0,1 %
6)
of moisture content .
5.9 Timer, for use with model MA 82 only.
5.10 Planimetric scales, supplied with the apparatus where an Alveolink is not included.
5.11 System for recording the test environment conditions (temperature and relative air humidity) as
specified in 8.1 and 9.1.
5.12 Volumetric flask, 1 000 ml capacity, complying with the requirements of ISO 1042, class A.
5.13 Pipette, 25 ml capacity, graduated in divisions of 0,1 ml, complying with the requirements of ISO 835,
class A.
6 Sampling
A representative wheat or flour sample should have been sent to the laboratory. It shall not have been
damaged or changed during transport or storage.
Sampling is not part of the method specified in this International Standard. Recommended sampling methods
[1]
are given in ISO 24333 .

4)
Alveolink is an example of a suitable product available commercially. This information is given for the convenience of
users of this International Standard and does not constitute an endorsement by ISO of this product.
5)
The methods specified in this International Standard are based on the use of the MA 82, MA 87, MA 95 and NG
models of Chopin alveograph.
6)
Throughout this International Standard, "content" is to be understood as a "mass fraction" (see EN ISO 80000-9[6],
12), i.e. the ratio of the mass of substance in a mixture to the total mass of the mixture.
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a) Kneading machine


b) Manometer c) Alveograph
Key
1 handle A in position 2
2 pump potentiometer
3 micrometric valve for air flow adjustment
Figure 1 — Model MA 82, MA 87 and MA 95 alveograph assemblies
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Key
1 micrometric valve for air flow adjustment
a
NG kneading machine.
b
NG integrator-recorder.
c
NG alveograph (with NG integrator-recorder).
Figure 2 — NG alveograph assembly with Alveolink integrator-recorder
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Key
1 micrometric valve for air flow adjustment
a
 NG kneading machine.
b
NG recording manometer.
c
NG alveograph (with hydraulic recording manometer).
Figure 3 — NG alveograph assembly with hydraulic recording manometer
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Table 1 — Specifications and characteristics of the accessories required for the test
Value and
Quantity
tolerance
Rotational frequency of the kneading machine blade
(60 � 2) Hz
Height of sheeting guides (12,0 � 0,1) mm
Large diameter of the sheeting roller (40,0 � 0,1) mm
Small diameter of the sheeting roller (33,3 � 0,1) mm
Inside diameter of the dough cutter (46,0 � 0,5) mm
Diameter of the aperture created when the moving plate opens (which determines the effective
(55,0 � 0,1) mm
diameter of the test piece)
Theoretical di
...