EN ISO 5529-2010 en Wheat - Determination of the sedimentation index - Zeleny test《小麦 沉降指数测定 沉降值试验》.pdf

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1、BRITISH STANDARDBS EN ISO 5529:2010Wheat Determination of the sedimentation index Zeleny testICS 67.060g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36

2、g58National forewordThis British Standard is the UK implementation of EN ISO 5529:2010. It is identical to ISO 5529:2007. It supersedes BS ISO 5529:2007 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee AW/4, Cereals and pulses.A list of organizations re

3、presented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.BS EN IS

4、O 5529:2010This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 September 2007 BSI 2010Amendments/corrigenda issued since publicationDate Comments 30 June 2010 This corrigendum renumbers BS ISO 5529:2007 as BS EN ISO 5529:2010 ISBN 978 0 580 69

5、804 0EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 5529 April 2010 ICS 67.060 English Version Wheat - Determination of the sedimentation index - Zeleny test (ISO 5529:2007) Bl tendre - Dtermination de lindice de sdimentation - Test de Zlny (ISO 5529:2007) Weizen - Bestimmung des Sedimenta

6、tionswertes - Zeleny-Test (ISO 5529:2007) This European Standard was approved by CEN on 13 March 2010. 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.

7、Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN 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

8、 under the responsibility of a CEN member into its own language and notified to the CEN 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, France, Ger

9、many, 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 COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUN

10、G Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 5529:2010: EForeword The text of ISO 5529:2007 has been prepared by Technical Committee ISO/TC 34 “Food products” of th

11、e International Organization for Standardization (ISO) and has been taken over as EN ISO 5529:2010 by 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

12、of an identical text or by endorsement, at the latest by October 2010, and conflicting national standards shall be withdrawn at the latest by October 2010. 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 n

13、ot 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 implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark

14、, 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. Endorsement notice The text of ISO 5529:2007 has been approved b

15、y CEN as a EN ISO 5529:2010 without any modification. BS EN ISO 5529:2010EN ISO 5529:2010 (E)iiiContents Page 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle. 1 5 Reagents 2 5.1 Reagents for the sedimentation test. 2 5.2 Preparation of the solutions 2 6 Apparatus 3 7 Sa

16、mpling 3 8 Preparation of the test flour. 4 9 Procedure 4 9.1 Test portion . 4 9.2 Determination 4 10 Expression of results . 4 11 Precision 5 11.1 Interlaboratory test . 5 11.2 Repeatability limit . 5 11.3 Reproducibility limit . 5 11.4 Critical difference 5 12 Test report . 6 Annex A (normative) S

17、ample grinding and sieving conditions according to the different types of mills 7 Annex B (informative) Interlaboratory test results . 9 Bibliography . 12 BS EN ISO 5529:2010EN ISO 5529:2010 (E)This page deliberately set blank1Wheat Determination of the sedimentation index Zeleny test 1 Scope This I

18、nternational Standard describes a method, known as the Zeleny sedimentation test, for assessing one of the factors determining the quality of wheat as a means of predicting the baking strength of the flour which can be made from it. The method is applicable only to Triticum aestivum L. wheat. 2 Norm

19、ative 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 565, Test sieves Metal wire

20、cloth, perforated metal plate and electroformed sheet Nominal sizes of openings ISO 648, Laboratory glassware One-mark pipettes ISO 3696, Water for analytical laboratory use Specification and test methods 3 Terms and definitions For the purposes of this document, the following terms and definitions

21、apply. 3.1 sedimentation index number indicating the volume of the sediment obtained, under the conditions specified in this International Standard, from a suspension of test flour, prepared from the wheat, in a solution of lactic acid and propan-2-ol NOTE 1 The sedimentation index is determined by

22、the Zeleny test. NOTE 2 The volume is expressed in millilitres. 4 Principle The measurement principle is based on the ability of the flour proteins to swell in an acid medium. Test flour, prepared from wheat under specified grinding and sieving conditions, is suspended in a solution of lactic acid a

23、nd propan-2-ol in the presence of a dye. After specified shaking and rest times, the obtained sediment volume corresponds to the sedimentation of the flour particles. BS EN ISO 5529:2010EN ISO 5529:2010 (E)2 5 Reagents Use reagents of recognized analytical grade, unless otherwise specified, and wate

24、r complying with grade 2 in accordance with ISO 3696, unless otherwise stated. 5.1 Reagents for the sedimentation test 5.1.1 Lactic (2-hydroxypropanoic) acid solution, at an aqueous volume fraction of 90 %, M = 90,08 g/mol, d = 1,20 to 1,22. 5.1.2 Propan-2-ol, at a volume fraction of 99 % to 100 %,

25、M = 60,10 g/mol. 5.1.3 Sodium hydroxide, standard solution, (NaOH) = 40 g/l. 5.1.4 Bromophenol blue, C19H10Br4O5S, solution. In a 1 000 ml volumetric flask (6.6), dissolve 4 mg of bromophenol blue in water, then make up to the mark with water. 5.1.5 Phenolphthalein, C20H14O4, solution. In a 100 ml v

26、olumetric flask (6.7), dissolve 1 g of phenolphthalein in ethanol at an aqueous volume fraction of 95 % to 96 %, then make up to the mark with ethanol. 5.2 Preparation of the solutions 5.2.1 Lactic acid stock solution Pour 235 ml of lactic acid solution (5.1.1) into a 1 000 ml volumetric flask (6.6)

27、 and adjust to the mark with water. Transfer the solution to the flask (6.8) and place the latter on the heating mantle (6.9). Bring to the boil and reflux for 6 h. Concentrated lactic acid solution contains associated molecules which, on dilution, dissociate slowly to equilibrium. Boiling accelerat

28、es this dissociation process which is essential in order to obtain reproducible sedimentation values. Leave to cool for at least 2 h prior to titration. Then titrate (6.12) 10 ml of this solution against sodium hydroxide (5.1.3) using phenolphthalein (5.1.5) as indicator (10 ml of lactic acid soluti

29、on require about 28 ml of sodium hydroxide). The concentration found shall be between 2,7 mol/l and 2,8 mol/l. Store the lactic acid stock solution in a tinted glass bottle. 5.2.2 Test solution In a 1 000 ml volumetric flask (6.6), mix 180 ml of the lactic acid stock solution (5.2.1) and 200 ml of p

30、ropan-2-ol (5.1.2), then make up to the mark with water. Store in a stoppered bottle. After preparation, only use the reagent after it has stood for a minimum of 48 h and within a maximum period of 15 days. BS EN ISO 5529:2010EN ISO 5529:2010 (E)36 Apparatus Usual laboratory apparatus and, in partic

31、ular, the following. 6.1 Test mill1)(see Annex A). 6.2 Woven metal wire sieve2), in accordance with the specifications of ISO 565, of nominal aperture size 150 m, of diameter 200 mm, moved by an appropriate automatic vibration device of eccentricity 50 mm and rotational frequency 200 min1. 6.3 Labor

32、atory sample divider. 6.4 Flat-bottom cylinders, of capacity 100 ml, graduated in millilitres, with a distance of 180 mm to 185 mm between the bottom and the 100 ml mark, and equipped with plastic or glass stoppers. 6.5 Cylinder shaker, fitted with a time switch and providing a shaking frequency of

33、40 min1; each cycle shall be through 60 (30 above and below the horizontal). 6.6 One-mark volumetric flasks, of capacity 1 000 ml. 6.7 One-mark volumetric flask, of capacity 100 ml. 6.8 Flask, of capacity 1 500 ml, equipped with a reflux condenser. 6.9 Heating mantle. 6.10 One-mark pipettes, of capa

34、city 25 ml and 50 ml, conforming to ISO 648, or automatic dispensers. 6.11 Analytical balance, capable of weighing to the nearest 0,01 g, with a readability of 0,001 g. 6.12 Equipment used for the titration of the lactic acid stock solution (5.2.1). 6.12.1 Two-mark pipette, of capacity 10 ml. 6.12.2

35、 Burette, of capacity 50 ml, graduated in 0,1 ml increments. 6.12.3 Beaker, of capacity 50 ml. 6.12.4 Magnetic stirrer and stirrer bar. 6.13 Stopwatch. 7 Sampling A representative sample should have been sent to the laboratory. It should not have been damaged or changed during transport or storage.

36、Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 13690. 1) The Miag-Grobschrotmhle; Brabender-Sedimat; Strand-Roll, model SRM; Straube, model W.1; and Tag-Heppenstall are examples of suitable products available commercially. T

37、his information is given for the convenience of users of this International Standard and does not constitute an endorsement by ISO of these products. 2) The Brabender-Sedimat mill incorporates a sieving device (see A.3). BS EN ISO 5529:2010EN ISO 5529:2010 (E)4 8 Preparation of the test flour Discar

38、d all the impurities from the wheat, either manually or using a mechanical grain cleaning machine. Mix, then divide the laboratory sample using a divider (6.3) until a mass corresponding to the type of mill (6.1) used for grinding (see Annex A) is obtained. Grind the grain and sieve the ground produ

39、ct as described in Annex A. Repeat this operation to obtain a second test sample. Grinding conditions differ according to the type of mill, but in all cases the particle size of the test flour shall be u150 m and the extracted mass W10 % of the mass of wheat used. 9 Procedure 9.1 Test portion Mix bo

40、th test flour samples (Clause 8). Weigh (6.11), to the nearest 0,05 g, two test portions of 3,2 g from each of the test samples. NOTE If there is any reason to think that the moisture content of the test flour is outside the range 13 % to 15 %, determine its value in accordance with ISO 712, then we

41、igh a quantity of test flour corresponding to 3,20 g 0,05 g at a moisture mass fraction of 14 % (i.e. 2,75 g 0,04 g of dry matter). 9.2 Determination Carry out the tests under normal lighting conditions, out of direct sunlight. Place the test portion (9.1) in a measuring cylinder (6.4). Using a pipe

42、tte or an automatic dispenser (6.10), add (50 0,5) ml of the bromophenol blue solution (5.1.4) to the test portion. Stopper the cylinder, and maintaining it in a horizontal position, shake it longitudinally from right to left, through approximately 18 cm to 20 cm, 12 times in each direction within a

43、pproximately 5 s. Place the cylinder in the shaker (6.5), then start the stopwatch (6.13) and the shaker. After 5 min, remove the cylinder from the shaker and using a pipette or the automatic dispenser (6.10) add to its contents 25 ml 0,2 ml of the test solution (5.2.2). Replace the cylinder in the

44、shaker and continue shaking for 5 min to give a total shaking time of 10 min. Remove the cylinder and place it in an upright position. Leave the contents of the cylinder to stand for 300 s 5 s, then note the volume of the deposit to the nearest 1 ml. 10 Expression of results The number indicating th

45、e volume, expressed in millilitres, of the deposit noted in 9.2 represents the sedimentation index. Take as the result the arithmetic mean of the results if the limit of repeatability is correct. If the difference exceeds the repeatability limit, r (11.2), repeat the operations described in 9.1 and

46、9.2. If the difference between the two new determinations does not exceed the repeatability limit, take the arithmetic mean of the two new determinations and discard the two first results. In the opposite case, take the arithmetic mean of the four individual determinations. Express the result as a w

47、hole number. BS EN ISO 5529:2010EN ISO 5529:2010 (E)511 Precision 11.1 Interlaboratory test Details of an interlaboratory test on the precision of the method are summarized in Annex B. The values derived from this interlaboratory test cannot be applied to other matrix and concentration ranges than t

48、hose given. 11.2 Repeatability limit The absolute difference between two independent single test results, obtained using the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, will in not more than 5 % of cases

49、 exceed the repeatability limit, r, calculated from the following equation: Z(0,009 8 0,317 9) 2,77rV=+ where ZV is the mean of the two test results, expressed in millilitres. 11.3 Reproducibility limit The absolute difference between two independent single test results, obtained using the same method on identical test material in different laboratories with different operators using different equipment, will in not more than 5 % of cases exceed the reproducibility limit, R, calculated from the following equation: Z(0,037 2 0,266 5) 2,77RV=+