BS DD CEN TS 15731-2008 Cereals and cereal products - Common wheat (Triticum aestivum L ) - Determination of alveograph properties of dough at adapted hydration from commercial or .pdf

1、DD CEN/TS15731:2008ICS 67.060NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWDRAFT FOR DEVELOPMENTCereals and cerealproducts Commonwheat (Triticumaestivum L.) Determination ofalveograph propertiesof dough at adaptedhydration fromcommercial or testflours and test millingmethodol

2、ogyLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/09/2009 07:28, Uncontrolled Copy, (c) BSIThis Draft for Developmentwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 May 2009 BSI 2009ISBN 978 0 580 60107 1Amendments/corrigenda issued since publicationDat

3、e CommentsDD CEN/TS 15731:2008National forewordThis Draft for Development is the UK implementation of CEN/TS15731:2008.This publication is not to be regarded as a British Standard.It is being issued in the Draft for Development series of publications andis of a provisional nature. It should be appli

4、ed on this provisional basis,so that information and experience of its practical application can beobtained.Comments arising from the use of this Draft for Development arerequested so that UK experience can be reported to the internationalorganization responsible for its conversion to an internation

5、al standard.A review of this publication will be initiated not later than 3 years afterits publication by the international organization so that a decision can betaken on its status. Notification of the start of the review period will bemade in an announcement in the appropriate issue of Update Stan

6、dards.According to the replies received by the end of the review period,the responsible BSI Committee will decide whether to support theconversion into an international Standard, to extend the life of theTechnical Specification or to withdraw it. Comments should be sent tothe Secretary of the respon

7、sible BSI Technical Committee at BritishStandards House, 389 Chiswick High Road, London W4 4AL.The UK participation in its preparation was entrusted to TechnicalCommittee AW/4, Cereals and pulses.A list of organizations represented on this committee can be obtained onrequest to its secretary.This pu

8、blication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/09/2009 07:28, Uncontrolled Cop

9、y, (c) BSIDD CEN/TS 15731:2008TECHNICAL SPECIFICATIONSPCIFICATION TECHNIQUETECHNISCHE SPEZIFIKATIONCEN/TS 15731August 2008ICS 67.060English VersionCereals and cereal products - Common wheat (Triticumaestivum L.) - Determination of alveograph properties of doughat adapted hydration from commercial or

10、 test flours and testmilling methodologyCrales et produits craliers - Bl tendre (Triticumaestivum L.) - Dtermination des propritsalvographiques dune pte hydratation constanteadapte de farine industrielle ou dessai et mthodologiepour la mouture dessaiGetreide und Getreideerzeugnisse - Weizen (Triticu

11、maestivum L.) - Bestimmung der Eigenschaften von Teig beiadaptierter Flssigkeitszufuhr zu handelsblichen Mehlenoder Versuchsmehlen bei gleichen Versuchsmahlverfahrenmittels AlveographThis Technical Specification (CEN/TS) was approved by CEN on 9 March 2008 for provisional application.The period of v

12、alidity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit theircomments, 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

13、 same way as for an EN and to make the CEN/TS availablepromptly 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 member

14、s 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, Swit

15、zerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. CEN

16、/TS 15731:2008: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/09/2009 07:28, Uncontrolled Copy, (c) BSIDD CEN/TS 15731:2008CEN/TS 15731:2008 (E) 2 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 Pr

17、eparation 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)

18、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.

19、 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

20、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 “Ie

21、c” 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 perfor

22、mance indicator. 31 A.6 Conversion performance indicator . 31 A.7 Maintenance operations. 31 Annex B (normative) Moisture required to condition wheat 32 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/09/2009 07:28, Uncontrolled Copy, (c) BSIDD CEN/TS 15731:2008CEN/TS 15731:2008 (E) 3 Anne

23、x 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 day36 E.3 Every week .36 E.4 Every month .36 E.5 Every year.37 Bibliography38 Licensed Copy

24、: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/09/2009 07:28, Uncontrolled Copy, (c) BSIDD CEN/TS 15731:2008CEN/TS 15731:2008 (E) 4 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. A

25、ttention 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 followi

26、ng 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, S

27、lovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/09/2009 07:28, Uncontrolled Copy, (c) BSIDD CEN/TS 15731:2008CEN/TS 15731:2008 (E) 5 Introduction The end-use value of wheat is determined by a number of properties that are useful i

28、n 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 bia

29、xial 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 provid

30、es 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

31、 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 i

32、s 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

33、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 pr

34、oportional 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). Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/09/2009

35、 07:28, Uncontrolled Copy, (c) BSIDD CEN/TS 15731:2008CEN/TS 15731:2008 (E) 6 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.) pr

36、oduced 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 millin

37、g 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 ap

38、plication 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,

39、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 constan

40、t 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. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/09/2009 07:28, Uncontroll

41、ed Copy, (c) BSIDD CEN/TS 15731:2008CEN/TS 15731:2008 (E) 7 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 chlori

42、de 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

43、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)

44、 at 20 C). 4.3 Cold degreasing agent - optimum safety.1)5 Apparatus Common laboratory equipment, including the following: 5.1 Mechanical cleaner fitted with sieves for wheat cleaning, in accordance with the manufacturers requirements. 5.2 Conical or riffle sample divider. 5.3 Analytical balance accu

45、rate to 0,01 g. 5.4 50 ml glass burette graduated in 0,1 ml increments, stand-mounted. 5.5 Rotary blender2)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 fo

46、r wheat preparation, the other for flour homogenisation). 5.5.3 Several wide-necked 2-litre plastic flasks. 5.6 Test mill3)(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 conveni

47、ence 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 a

48、nd 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 th

49、is this product. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 11/09/2009 07:28, Uncontrolled Copy, (c) BSIDD CEN/TS 15731:2008CEN/TS 15731:2008 (E) 8 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