DIN EN ISO 17715-2015 Flour from wheat (Triticum aestivum L ) - Amperometric method for starch damage measurement (ISO 17715 2013) German version EN ISO 17715 2014《小麦粉 (普通小麦Triticu.pdf

1、March 2015 Translation by DIN-Sprachendienst.English price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS

2、67.060!%Aa,“2306209www.din.deDDIN EN ISO 17715Flour from wheat (Triticum aestivum L.) Amperometric method for starch damage measurement(ISO 17715:2013);English version EN ISO 17715:2014,English translation of DIN EN ISO 17715:2015-03Weizenmehl (Triticum aestivum L.) Messung der Strkebeschdigung mitt

3、els amperometrischer Methode (ISO 17715:2013);Englische Fassung EN ISO 17715:2014,Englische bersetzung von DIN EN ISO 17715:2015-03Farine de bl tendre (Triticum aestivum L.) Mthode ampromtrique pour le mesurage de l endommagement de l amidon(ISO 17715:2013);Version anglaise EN ISO 17715:2014,Traduct

4、ion anglaise de DIN EN ISO 17715:2015-03www.beuth.deDocument comprises 19 pagesIn case of doubt, the German-language original shall be considered authoritative.03.15 DIN EN ISO 17715:2015-03 2 A comma is used as the decimal marker. National foreword The text of this document (ISO 17715:2013) has bee

5、n prepared by Technical Committee ISO/TC 34 “Food products” (Secretariat: AFNOR, France), Subcommittee SC 4 “Cereals and pulses” (Secretariat: SAC, China) and has been taken over as EN ISO 17715:2014 by Technical Committee CEN/TC 338 “Cereal and cereal products” (Secretariat: AFNOR, France). The res

6、ponsible German body involved in its preparation was the DIN-Normenausschuss Lebensmittel und landwirtschaftliche Produkte (DIN Standards Committee Food and Agricultural Products), Working Committee NA 057-05-06 AA Getreide und Getreideerzeugnisse. EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM E

7、N ISO 17715 December 2014 ICS 67.060 English Version Flour from wheat (Triticum aestivum L.) - Amperometric method for starch damage measurement (ISO 17715:2013) Farine de bl tendre (Triticum aestivum L.) - Mthode ampromtrique pour le mesurage de lendommagement de lamidon (ISO 17715:2013) Weizenmehl

8、 (Triticum aestivum L.) - Messung der Strkebeschdigung mittels amperometrischer Methode (ISO 17715:2013) This European Standard was approved by CEN on 16 December 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European S

9、tandard 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 (Eng

10、lish, 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,

11、 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, Switzerlan

12、d, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Mem

13、bers. Ref. No. EN ISO 17715:2014 EContents PageForeword 3Introduction 41 Scope . 52 Terms and definitions . 53 Principle 54 Reagents 55 Equipment . 66 Sampling 67 Procedure. 67.1 Reagent weighing and dissolution . 67.2 Sample weighing . 67.3 Test 67.4 Cleaning . 77.5 Number of determinations . 78 Ex

14、pression of results 79 Precision . 79.1 Interlaboratory tests 79.2 Repeatability limits, r .77879.3 Reproducibility limits, R 89.4 Critical difference, dC889.5 Uncertainty, u 910 Test report . 9Annex A (informative) Data from interlaboratory tests on wheat flour . 10Bibliography .172DIN EN ISO 17715

15、:2015-03 EN ISO 17715:2014 (E)Foreword The text of ISO 17715:2013 has been prepared by Technical Committee ISO/TC 34 “Food products” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 17715:2014 by Technical Committee CEN/TC 338 “Cereal and cereal products”

16、 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 June 2015, and conflicting national standards shall be withdrawn at the latest by June 2015. Attention i

17、s 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. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the fo

18、llowing 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

19、, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 17715:2013 has been approved by CEN as EN ISO 17715:2014 without any modification. 3DIN EN ISO 17715:2015-03 EN ISO 17715:2014 (E)IntroductionDamaged

20、 starch content is an important parameter in flour quality as it directly impacts the flour water absorption capacity and therefore its use in the agri-food industry.In the past, a number of methods based on various principles were developed to estimate such content, but comparing the results is dif

21、ficult due to the different principles and units of measurement used.A laboratory device is dedicated to the determination of damaged starch content using an amperometric method and which offers a choice of units of measurement according to individual references.4DIN EN ISO 17715:2015-03 EN ISO 1771

22、5:2014 (E)1 ScopeThis International Standard specifies the determination of the damage to starch using an amperometric method.It is applicable to all flour samples from industrial or laboratory milling of wheat (Triticum aestivum L.).NOTE 1 Wheat can be milled in the laboratory according to the meth

23、ods described in ISO 279719or in BIPEA guidance document BY.102.D.9302.10NOTE 2 In the absence of validity studies, the results on semi-wholemeal or wholemeal flour, although able to meet the conditions of repeatability given in Clause 9, require careful interpretation.2 Terms and definitionsFor the

24、 purposes of this document, the following terms and definitions apply.2.1damaged starchstarch granules present in wheat flour mechanically damaged during milling, leading to a greater capacity to absorb water and increasing susceptibility to amylolytic enzymesNote 1 to entry: Too high a damaged star

25、ch content has a negative effect on quality of flours.3 PrincipleDetermination of damaged starch content of a flour sample by measurement of iodine absorption kinetics in an aqueous medium using an amperometric electrode.The amperometric method is based on the existing proportionality between iodine

26、 absorption capacity and starch damage content.4 ReagentsUse only reagents of recognized analytical grade, unless otherwise specified.4.1 Water, osmosed or demineralized or at least equivalent grade.4.2 Boric acid or citric acid, powdered, for testing.WARNING The use of boric acid involves hazardous

27、 operations. This document does not purport to address all the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure complaince with any national regulatory conditions.4.3 Potassium iodide, powdered,

28、for testing.4.4 Sodium thiosulfate, solution in water at 0,1 mol/l prepared from a ready-to-use vial containing 0,1 mol sodium thiosulfate, to be diluted with water (4.1) in a 1 l flask. Powdered sodium thiosulfate can 5DIN EN ISO 17715:2015-03 EN ISO 17715:2014 (E)also be used where the concentrati

29、on of the final solution is 0,1 mol/l. Protect the solution from light and use within 3 months.5 EquipmentUsual laboratory apparatus and, in particular, the following.5.1 Chopin SDmatic,1)equipped with a reaction vessel and sample holder.NOTE This International Standard has been developed using the

30、Chopin SDmatic.1)It does not apply to the SD4 Chopin and Rapid FT devices which also measure damaged starch content, but using different technology.5.2 Laboratory scales, with a display accuracy of 102g enabling weighing at 101g accuracy.5.3 Laboratory scales, with a display accuracy of 104g enablin

31、g weighing at 103g accuracy.5.4 Piston distributor, delivering 120 ml distilled water to the nearest 0,5 ml.5.5 One-mark volumetric flask, capacity 1 000 ml, ISO 1042,2class A.6 SamplingSampling is not part of the method specified in this International Standard. A recommended sampling method is give

32、n in ISO 24333.8It is important the laboratory receive a truly representative sample which has not been damaged or changed during transport or storage.7 Procedure7.1 Reagent weighing and dissolutionWeigh (5.2), to the nearest 0,5 g, 3,0 g boric acid (4.2) or 1,5 g citric acid (4.2) and 3,0 g (4.3) p

33、otassium iodide and add to a clean and dry reaction vessel (5.1). Add one drop (about 0,04 ml) of sodium thiosulfate solution (4.4) and dispense (5.4) 120 ml distilled water (4.1) into the vessel.As the test begins with a heating and stirring phase, it is not necessary to obtain full dissolution of

34、the reagents at this stage. In order to minimize losses during transfer, add powdered reagents directly to the reaction vessel.7.2 Sample weighingWeigh (5.3), to the nearest 103g, 1,000 g 0,100 g of the test sample of flour and place it in the pre-cleaned sample holder (5.1).7.3 TestPlace the reacti

35、on vessel in the well on the device.Lower the head of the device, and insert the sample holder containing the flour (7.2) into the compartment.1) Chopin SDmaticis the trade name of a product supplied by Chopin Technologies. This information is given for the convenience of users of this document and

36、does not constitute an endorsement by ISO of the product named. Equivalent products may be used if they can be shown to lead to the same results.6DIN EN ISO 17715:2015-03 EN ISO 17715:2014 (E)Start the test. Indicate the exact mass of the test portion of flour weighed to the nearest 0,001 g. It is a

37、lso possible to indicate the water and protein content of the sample if a result corrected on this basis is to be obtained, otherwise the default values should be left (mass fractions of 14 % and 12 %, respectively) for the two components. Confirm the start of the test.The test lasts 6 min to 7 min.

38、 Ensure that all of the flour descends into the reaction vessel when the vibrator starts up. Use the tip of a brush or lightly blow to enable any remaining flour to fall.Wait for the beep at the end of the test at which point the result is displayed.7.4 CleaningRaise the head of the device and remov

39、e the reaction vessel. Rinse, then carefully and gently wipe the measuring electrode, the heating element and the stirrer.Remove any residue from the vessel (do not dispose of in the sink). Carefully wash and wipe dry the reaction vessel, which shall be free of all traces of reagent, sample or moist

40、ure, and which shall be left ready for use in a later test.7.5 Number of determinationsPerform two determinations on the same test sample.8 Expression of resultsThe result is expressed as AI% (iodine absorption percentage) converted into UCD (ChopinDubois units). Equations provided by the manufactur

41、er can be used to calculate the equivalence in another unit.The arithmetic mean of the two determinations (7.5) shall be taken as the result if they meet the conditions of repeatability specified in 9.2 or in Table A.5. Otherwise, perform two new determinations.NOTE It can be useful to calculate sta

42、rch damage on a constant water and protein content basis. In this case, flour moisture content and protein content can be determined in accordance with ISO 7121for moisture and ISO 204837or ISO/TS 16634-26for protein.9 Precision9.1 Interlaboratory testsTwo interlaboratory tests established the repea

43、tability and reproducibility limits of the method. The statistical results of the study are given in Annex A.The values of each of the studies apply to the concentration ranges and flours from wheat (Triticum aestivum L.).9.2 Repeatability limits, rRepeatability limit is the value below which the ab

44、solute value, of the difference between two test results obtained in conditions of repeatability is located, with a probability of 95 %.The repeatability limits, r, are obtained from Formulae (1) and (2). Some repeatability limit values are listed in Table A.5.For AI%:rA= +()0 007 0 787128,%I (1)whe

45、re AI%is the mean iodine absorption capacity.7DIN EN ISO 17715:2015-03 EN ISO 17715:2014 (E)For UCD:r = (0,007UCD+ 0,473 9) 2,8 (2)where UCDis the mean ChopinDubois unit value.9.3 Reproducibility limits, RReproducibility limit is the value below which the absolute value, of the difference between tw

46、o test results obtained in conditions of reproducibility is located, with a probability of 95 %.The reproducibility limits, R, are obtained from Formulae (3) and (4). Some reproducibility limit values are listed in Table A.6.For AI%:RA= +()0033074528,%,I (3)For UCD:R = (0,041UCD+ 1,522 2) 2,8 (4)9.4

47、 Critical difference, dCThe critical difference is the deviation between two average values obtained from two test results under repeatability conditions.9.4.1 Comparison of two measurement groups in the same laboratoryThe critical difference for comparing two average values obtained from two test r

48、esults in the same laboratory under repeatability conditions, dC,r, is given by:dsnnssCr rrr,=+=281212281219812(5)wheresris the repeatability standard deviation;n1, n2are the number of test results for each of the average values here, n1and n2equal 2.8DIN EN ISO 17715:2015-03 EN ISO 17715:2014 (E)9.

49、4.2 Comparison of two measurement groups in two different laboratoriesThe critical difference for comparing two average values obtained from two test results in two different laboratories under repeatability conditions, dC,R, is equal to:dssnnssCR Rr Rr,=28 1121228 05221222(6)where:sris the repeatability standard deviation;sRis the reproducibility standard deviation;n1, n2are the number of test results for each of the average values here, n1and n2equal 2.Some critical difference values between