1、BRITISH STANDARDBS EN ISO 21415-4:2007Wheat and wheat flour Gluten content Part 4: Determination of dry gluten from wet gluten by a rapid drying methodThe European Standard EN ISO 21415-4:2007 has the status of a British StandardICS 67.060g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g
2、44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 21415-4:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2007 BSI 2007ISBN 978 0
3、580 50580 5National forewordThis British Standard was published by BSI. It is the UK implementation of EN ISO 21415-4:2007. It is identical with ISO 21415-4:2006.The UK participation in its preparation was entrusted to Technical Committee AW/4, Cereals and pulses.A list of organizations represented
4、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.Amendments issued
5、since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 21415-4March 2007ICS 67.060English VersionWheat and wheat flour - Gluten content - Part 4: Determinationof dry gluten from wet gluten by a rapid drying method (ISO21415-4:2006)Bl et farines de bl - Teneur en
6、 gluten - Partie 4:Dtermination du gluten sec partir du gluten humide parune mthode de schage rapide (ISO 21415-4:2006)Weizen und Weizenmehl - Glutengehalt - Teil 4:Bestimmung des Trockenglutens aus Feuchtgluten mittelsSchnelltrocknungsverfahren (ISO 21415-4:2006)This European Standard was approved
7、by CEN on 25 February 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstand
8、ards 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 translationunder the responsibility of a CEN member into its own language and notified to
9、the CEN Management Centre has the same status as theofficial versions.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, Nether
10、lands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in a
11、ny form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 21415-4:2007: EForeword The text of ISO 21415-4:2006 has been prepared by Technical Committee ISO/TC 34 “Agricultural food products” of the International Organization for Standardization (ISO) and has been taken over
12、 as EN ISO 21415-4:2007 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 of an identical text or by endorsement, at the latest by September 2007, a
13、nd conflicting national standards shall be withdrawn at the latest by September 2007. 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, Cyprus, Czech Republic,
14、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. Endorsement notice The text of ISO 21415-4:2006 has been appr
15、oved by CEN as EN ISO 21415-4:2007 without any modifications. EN ISO 21415-4:2007Reference numberISO 21415-4:2006(E)INTERNATIONAL STANDARD ISO21415-4First edition2006-05-01Wheat and wheat flour Gluten content Part 4: Determination of dry gluten from wet gluten by a rapid drying method Bl et farines
16、de bl Teneur en gluten Partie 4: Dtermination du gluten sec partir du gluten humide par une mthode de schage rapide EN ISO 21415-4:2007ii iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle. 1 5 Apparatus 2 6 Procedure 2 6.1 Preparation of the d
17、rying plates 2 6.2 Drying wet gluten 2 7 Calculation and expression of results 2 7.1 Calculation of the dry gluten content . 2 7.2 Calculation of water content of the wet gluten3 8 Precision 3 8.1 Interlaboratory tests . 3 8.2 Repeatability 3 8.3 Reproducibility 3 9 Test report . 3 Annex A (normativ
18、e) Electrically heated drying plates 4 Annex B (informative) Results of an interlaboratory test. 5 Bibliography . 6 EN ISO 21415-4:2007iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparin
19、g 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 liai
20、son 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 t
21、echnical 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 d
22、rawn 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 21415-4 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 4, Cereals and pulses. Th
23、is first edition of ISO 21415-4, together with ISO 21415-3:2006, cancels and replaces ISO 6645:1981, which has been technically revised. ISO 21415 consists of the following parts, under the general title Wheat and wheat flour Gluten content: Part 1: Determination of wet gluten by a manual method Par
24、t 2: Determination of wet gluten by mechanical means Part 3: Determination of dry gluten from wet gluten by an oven drying method Part 4: Determination of dry gluten from wet gluten by a rapid drying method EN ISO 21415-4:20071Wheat and wheat flour Gluten content Part 4: Determination of dry gluten
25、from wet gluten by a rapid drying method 1 Scope This part of ISO 21415 specifies a rapid method for the determination of the dry gluten content from wet gluten obtained as specified in either ISO 21415-1 or ISO 21415-2. The method can also be used to determine the moisture content of the wet gluten
26、. 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 21415-1, Wheat and w
27、heat flour Gluten content Part 1: Determination of wet gluten by a manual method ISO 21415-2, Wheat and wheat flour Gluten content Part 2: Determination of wet gluten by mechanical means 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 wet glu
28、ten visco-elastic substance, composed principally of two protein fractions (gliadin and glutenin) in a hydrated form, obtained as specified in ISO 21415-1 or ISO 21415-2 3.2 dry gluten residue obtained from wet gluten dried according to the conditions specified in ISO 21415-3 or in this part of ISO
29、21415 4 Principle A ball of wet gluten obtained under the conditions specified in ISO 21415-1 or ISO 21415-2 is dried then weighed. EN ISO 21415-4:20072 5 Apparatus Usual laboratory apparatus and, in particular, the following. 5.1 Electrically heated drying plates, made up of two plates coated with
30、anti-adhesion material and heated by resistance coils to reach a working temperature of 150 C to 200 C (see Annex A). 5.2 Balance, capable of weighing to the nearest 0,01 g. 6 Procedure 6.1 Preparation of the drying plates Allow the drying plates (5.1) to reach operating temperature by running one d
31、rying cycle prior to commencing the test. 6.2 Drying wet gluten Take a ball of wet gluten obtained by the method specified in ISO 21415-1 or ISO 21415-2, from which most of the washing solution has been eliminated and which has been weighed to the nearest 0,01 g (m7). Place it between the prewarmed
32、drying plates (5.1) for 300 s 5 s. Remove the dried gluten from the drying plates and weigh to the nearest 0,01 g (m6). 7 Calculation and expression of results 7.1 Calculation of the dry gluten content The dry gluten content (Gdry), expressed as a mass fraction, in percent, of the original sample (w
33、heat flour, reground semolina or ground wheat) is equal to 6dry100 %mGm= where m6is the mass of dry gluten, in grams; m is the mass, in grams, of the portion of the original sample of dough taken for determination of the wet gluten content. It is necessary to know the mass of the original sample (m)
34、 from which the wet gluten was extracted. It should be noted that in the case of the manual washing out procedure this is not equal to the mass of the test portion of the original sample. If the moisture content of the original sample, determined in accordance with ISO 712, is taken into account, th
35、e dry gluten content on a dry matter basis (Gdm), in percent, is equal to 6dm100100 %(100 )mGmw=where w is the moisture content of the original sample, as a mass fraction in percent. Take as the result the arithmetic mean of two determinations. EN ISO 21415-4:200737.2 Calculation of water content of
36、 the wet gluten The water content of the wet gluten (wG), expressed as mass fraction in percent, is equal to 76G7100 %mmwm= where m7is the mass of wet gluten, in grams. 8 Precision 8.1 Interlaboratory test Details of an interlaboratory test on the precision of the method are summarized in Annex B. T
37、he values derived from this interlaboratory test may not be applicable to concentration ranges and matrices other than those given. 8.2 Repeatability The absolute difference between two independent single test results, obtained using the same method on identical test material in the same laboratory
38、by the same operator using the same equipment within a short interval of time, will in not more than 5 % of cases be greater than 0,6 g/100 g, starting from either the manual or the mechanical determination of wet gluten. 8.3 Reproducibility The absolute difference between two single test results, o
39、btained 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 be greater than the values given below: starting from the manual determination of wet gluten: R = 4,1 g/100 g; starting from the m
40、echanical determination of wet gluten: R = 2,0 g/100 g. 9 Test report The test report shall specify: a) all information necessary for the complete identification of the sample; b) the sampling method used, if known; c) the test method used, with reference to this part of ISO 21415 and reference to t
41、hat part of ISO 21415 which was used for the determination of wet gluten; d) all operating details not specified in this part of ISO 21415, or regarded as optional, together with details of any incidents that occurred when performing the method, which may have influenced the test result(s); e) the t
42、est result(s) obtained; f) if the repeatability has been checked, the final quoted result obtained. EN ISO 21415-4:20074 Annex A (normative) Electrically heated drying plates EN ISO 21415-4:20075Annex B (informative) Results of an interlaboratory test The interlaboratory test involving 21 laboratori
43、es in 7 countries was organized by the CONCORDIA Warehouse Ltd., Grain Control Laboratory, Budapest (Hungary) in 2004. It was carried out on the following six samples: Sample A: wheat (Triticum aestivum L.) as grain; Sample B: wheat (Triticum aestivum L.) as grain; Sample C: wheat (Triticum durum De
44、sf.) as grain; Sample D: durum wheat semolina; Sample E: wheat flour; Sample F: wheat flour. The results obtained were subjected to statistical analysis in accordance with ISO 5725-1 and ISO 5725-2 to give the precision data shown in Tables B.1 and B.2. Table B.1 Precision data for dry gluten, start
45、ing from wet gluten obtained by ISO 21415-1 Samples A B C D E F Number of laboratories after eliminating outliers 6 6 6 6 5 5 Mean value, g/100 g 8,38 11,04 10,34 12,54 9,65 12,03 Repeatability standard deviation, sr, g/100 g 0,18 0,20 0,36 0,25 0,26 0,12 Coefficient of variation of repeatability, %
46、 2,11 1,82 3,46 1,96 2,72 1,02 Repeatability limit r (= 2,8 sr), g/100 g 0,49 0,56 1,00 0,69 0,74 0,34 Reproducibility standard deviation, sR, g/100 g 1,01 1,24 1,32 2,71 0,86 1,57 Coefficient of variation of reproducibility, % 12,11 11,26 12,77 21,65 8,96 13,09 Reproducibility limit R (= 2,8 sR), g
47、/100 g 2,84 3,48 3,70 7,60 2,42 4,41 Table B.2 Precision data for dry gluten, starting from wet gluten obtained by ISO 21415-2 Samples A B C D E F Number of laboratories after eliminating outliers 6 7 7 8 6 6 Mean value, g/100 g 8,47 11,37 10,76 13,04 9,18 11,69 Repeatability standard deviation, sr,
48、 g/100 g 0,18 0,18 0,19 0,44 0,13 0,14 Coefficient of variation of repeatability, % 2,12 1,55 1,73 3,35 1,44 1,18 Repeatability limit r (= 2,8 sr), g/100 g 0,50 0,49 0,52 1,22 0,37 0,39 Reproducibility standard deviation, sR, g/100 g 0,46 0,74 0,65 1,74 0,20 0,42 Coefficient of variation of reproduc
49、ibility, % 5,48 6,48 6,07 13,38 2,19 3,58 Reproducibility limit R (= 2,8 sR), g/100 g 1,30 2,06 1,83 4,89 0,56 1,17 EN ISO 21415-4:20076 Bibliography 1 ISO 712, Cereals and cereal products Determination of moisture content Routine reference method 2 ISO 21415-3, Wheat and wheat flour Gluten content Part 3: Determination of dry gluten from wet gluten by an oven drying method EN ISO 21415-4:2007blankBS EN ISO 21415-4:2007BSI389 Chiswick High RoadLondonW4 4ALBSI British Standards InstitutionBSI is t
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