1、November 2008DEUTSCHE NORM English price group 9No part of this standard 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 67.060!$Rg“1476896www.
2、din.deDDIN EN 15585Cereals and cereal products Durum wheat (T. durum Desf.) Determination of percentage of mitadine grains and calculation ofEnglish version of DIN EN 15585:2008-11Getreide und Getreideerzeugnisse Hartweizen (T. durum Desf.) Bestimmung des prozentualen Anteils an mehligen Krnern und
3、Berechnung desprozentualen Anteils an glasigen KrnernEnglische Fassung DIN EN 15585:2008-11www.beuth.deDocument comprises 13 pagespercentage of vitreous grainsDIN EN 15585:2008-11 2 National foreword This standard has been prepared by Technical Committee CEN/TC 338 “Cereal and cereal products” (Secr
4、etariat: AFNOR, France). The responsible German body involved in its preparation was the Normenausschuss Lebensmittel und landwirtschaftliche Produkte (Food and Agricultural Products Standards Committee), Technical Committee NA 057-05-06 AA Getreide und Getreideerzeugnisse. EUROPEAN STANDARDNORME EU
5、ROPENNEEUROPISCHE NORMEN 15585July 2008ICS 67.060English VersionCereals and cereal products - Durum wheat (T. durum Desf.) -Determination of percentage of mitadine grains and calculationof percentage of vitreous grainsCrales et produits craliers - Bl dur (T. durum Desf.) -Dtermination du taux de mit
6、adinage et calcul du taux devitrositDesf.) - Bestimmung des prozentualen Anteils an mehligenKrnern und Berechnung des prozentualen Anteils anglasigen KrnernThis European Standard was approved by CEN on 21 June 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipu
7、late the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exi
8、sts 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 the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bod
9、ies 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, Switzerland and United Kingdom.EUROP
10、EAN 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. EN 15585:2008: EGetreide- und Getre
11、ideerzeugnisse - Hartweizen (T. durumEN 15585:2008 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Principle4 5 Apparatus .5 6 Sampling.5 7 Procedure .5 8 Expression of results 6 9 Precision.7 10 Test report 8 Results of interlaboratory tests.9 Bibliogra
12、phy 11 Annex A (informative)9 DIN EN 15585:2008-11 EN 15585:2008 (E) 3 Foreword This document (EN 15585:2008) has been prepared 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 st
13、andard, either by publication of an identical text or by endorsement, at the latest by January 2009, and conflicting national standards shall be withdrawn at the latest by January 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent righ
14、ts. 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 following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Cz
15、ech Republic, 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 the United Kingdom. DIN EN 15585:2008-11 EN 15585:2008 (E) 4 1
16、Scope This European Standard specifies a reference method for the determination of the proportion of mitadine grains, applicable exclusively to durum wheat (Triticum durum Desf.). 2 Normative references The following referenced documents are indispensable for the application of this document. For da
17、ted references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 15587, Cereals and cereal products - Determination of Besatz in wheat (Triticum aestivum L.), durum wheat (Triticum durum Desf.), rye (Secale c
18、ereale L.) and feed barley (Hordeum vulgare L.) EN ISO 6644, Flowing cereals and milled cereal products - Automatic sampling by mechanical means (ISO 6644:2002) EN ISO 13690, Cereals, pulses and milled products - Sampling of static batches (ISO 13690:1999) prEN ISO 24333, Cereals and cereal products
19、 - Sampling (ISO/DIS 24333:2008) ISO 5223, Test sieves for cereals 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 vitreous grain translucent grain, the cut grain having a smooth, shiny surface without any mealy appearance 3.2 mitadine grain
20、durum wheat grain which is not considered to be completely vitreous under the conditions of this European Standard NOTE In some countries, these grains are also called piebald grains. 3.3 proportion of mitadine grains percentage by mass of mitadine grains in a sample of durum wheat as determined wit
21、h the method described in this European Standard 3.4 proportion of vitreous grains percentage by mass as calculated with the formula given in 8 4 Principle Removal of any impurities, including grains of common wheat (Triticum aestivum), by sifting and sorting by hand according to EN 15587, followed
22、by separation of visibly mitadine grains, and verification of the vitreous state of the other grains after cutting with a scalpel. DIN EN 15585:2008-11 EN 15585:2008 (E) 5 5 Apparatus 5.1 Sample divider 5.2 Sieve, with perforated plate having slots 1,9 mm x 20,0 mm, complying with the requirements o
23、f ISO 5223. 5.3 Scalpel. 5.4 Balance, having an accuracy of 0,1 g. 6 Sampling It is important the laboratory receive a sample which is truly representative and has not been damaged or changed during transport and storage. Sampling is not part of the method specified in this International Standard. R
24、ecommended sampling methods are given in EN ISO 6644, EN ISO 13690 and prEN ISO 24333. 7 Procedure 7.1 Preparation of the test sample 7.1.1 Take approximately 50 g of the laboratory sample using the sample divider (5.1), and weigh it to the nearest 0,1 g (mass m). 7.1.2 Place the test sample on the
25、sieve (5.2) and shake by hand or machine for 30 s, keeping the sieve horizontal and moving it in the direction parallel with the length of the slots. Discard the material passing through the sieve. 7.1.3 Remove by hand any impurities in the sample retained on the sieve. Grains of common wheat (Triti
26、cum aestivum L.) shall be considered to be impurities. 7.2 Test portion Weigh the mass of durum wheat grains thus prepared to the nearest 0,1 g. 7.3 Determination 7.3.1 Spread the test portion (7.2) over a flat surface. Examine each grain individually with the naked eye (corrected, if necessary, for
27、 abnormal vision). 7.3.2 Separate out all grains which are visibly mitadine. NOTE Do not confuse mitadine grains with “washed grains”, the external appearance of which is similar to that of completely mealy grains, but which differ in their dull appearance. Washed grains are not necessarily mealy. 7
28、.3.3 Using the scalpel (5.3), cut transversely all the remaining grains through the middle and remove both parts of each grain which, when cut, prove to be mitadine. 7.3.4 Gather and weigh to the nearest 0,1 g: firstly, grains which are visibly mitadine, and both parts of those grains which when cut
29、 proved to be mitadine (mass m1); secondly, the parts of the vitreous grains (mass m2). DIN EN 15585:2008-11 EN 15585:2008 (E) 6 7.3.1 The determination is considered to be valid if (m1+ m2) does not differ from the mass of the test portion (7.2) by more than 0,5 %. If this is not the case, carry ou
30、t the determination again on a new test sample. 8 Expression of results 8.1 Methods of calculation and formulae 8.1.1 The proportion of mitadine grains, expressed in percentage regarding the raw sample as received (7.1.1) (before sieving and removal of impurities), is equal to: 1001mm(1) where m is
31、the mass, in grams, of the test sample taken in 7.1.1; m1is the mass, in grams, of the mitadine grains (see 7.3). 8.1.2 The proportion of mitadine grains, expressed in percentage regarding the sieved test sample from which impurities have been removed (7.1.3), is equal to: 100211+ mmm(2) where m1is
32、the mass, in grams, of the mitadine grains (see 7.3); m2 is the mass, in grams, of the vitreous grains (see 7.3). 8.1.3 The proportion of vitreous grains, expressed in percentage regarding the raw sample as received (7.1.1), is equal to: 1002mm(3) where mis the mass, in grams, of the test sample tak
33、en in 7.1.1. m2is the mass, in grams, of the vitreous grains (see 7.3). 8.1.4 The proportion of vitreous grains, expressed in percentage regarding the sieved test sample from which impurities have been removed (7.1.3), is equal to: 100212+ mmm(4) where m1is the mass, in grams, of the mitadine grains
34、 (see 7.3); m2 is the mass, in grams, of the vitreous grains (see 7.3). DIN EN 15585:2008-11 EN 15585:2008 (E) 7 8.2 Number of determinations Carry out two determinations on different samples taken from the same laboratory sample. If the difference between the two determinations is bigger than the r
35、epeatability limit (see 9.1), carry out two new determinations. If with these two other determinations, the difference is bigger than the repeatability limit, take the mean of the four determinations as the result. If the difference between the two determinations is lower or equal to the repeatabili
36、ty limit (see 9.1), take the mean of the two determinations as the result. Express the result with one decimal. 9 Precision 9.1 Interlaboratory test Details of an international interlaboratory test on the precision of the method are summarized in Annex A. The values derived from this test may not be
37、 applicable to mitadine concentration ranges and matrices other than those given, namely from 10 % to 55 %. 9.2 Repeatability limit (r) 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 op
38、erator using the same equipment within a short interval of time will not in more that 5 % of cases be greater than the repeatability limit (r) given hereunder: r = 2,77 x sr= 2,77 x (1,05) = 2,9 (5) where sris the repeatability standard deviation. 9.3 Reproducibility limit (R) The absolute differenc
39、e between two single test results, obtained using the same method on identical test material in different laboratories with different operators using different equipment, will not in more that 5 % of cases be greater than the reproducibility limit (R) given hereunder: R = 2,77 x sR= 2,77 x 3,43 = 9,
40、5 (6) where sRis the reproducibility standard deviation. 9.4 Critical difference (CD) When the difference between two averaged values obtained from two test results under repeatability conditions is to be assessed, the repeatability limit cannot be used: Critical Difference shall be used. 9.4.1 Comp
41、arison of two groups of measurements in one laboratory The critical difference (CD1) between two averaged values obtained in one laboratory from two test results under repeatability conditions is equal to: 06,2 96,12177,2 21212,77 211=+=rrrssnnsCD (7) DIN EN 15585:2008-11 EN 15585:2008 (E) 8 where s
42、ris the standard deviation of repeatability; n1and n2are the number of test results corresponding to each of the averaged values (here, n1= n2= 2). 9.4.2 Comparison of two groups of measurements in two laboratories The critical difference (CD2) between two averaged values obtained in two different l
43、aboratories from two test results under repeatability conditions is equal to: 9,28 5,0 77,2 21211 - 2,77 22212r22=rRRssnnssCD (8) where sris the standard deviation of repeatability; sRis the standard deviation of reproducibility; n1and n2are the number of test results corresponding to each of the av
44、eraged values (here, n1= n2= 2). 9.5 Uncertainty (Ue) The measurement uncertainty (Ue) is a parameter representing the distribution of the values that may reasonably be attributed to the result. This uncertainty is given by a statistical distribution of the results from the interlaboratory test and
45、is characterized by the experimental standard deviation. The uncertainty (Ue) is equal to plus or minus twice the reproducibility standard deviation given in this European Standard: for products whose mitadine fraction is between 10 % to 55 % (see Table A.1 and Figure A.1): Ue = 2 x sR= 2 x 3,43 = 6
46、,86 (9) where sRis the standard deviation of reproducibility. 10 Test report The test report shall show the method used, the results obtained, and the method of expressing the results. It shall also include all details of the procedure not specified in this European Standard, or regarded as optional
47、, as well as any circumstances that may have influenced the results, of which the number of determination carried out to obtain the result. The test report shall contain all information necessary for complete identification of the sample. DIN EN 15585:2008-11 EN 15585:2008 (E) 9 ANNEX A (informative
48、) Results of interlaboratory tests An international interlaboratory test was carried out on 6 samples of durum wheat. 12 laboratories in 3 countries have participated. This test was organized by the BIPEA in May 2007 with financial support from ONIGC (Office National Interprofessionnel des Grandes C
49、ultures) and ANMAC (Association pour la Normalisation des Mthodes dAnalyses des Crales). The results obtained were subjected to statistical analysis in accordance with the parts 1, 2 and 6 of ISO 5725 to give the precision data shown in table A. Table A.1 - Precision data for mitadine grains fraction Samples Parameters 1 2 3 4 5 6 Number of laboratories after eliminating outliers 9 10 9 10 8 10 Mean value 11,3 34,0 24,1 33,7 11,4 56,8 Repeatability standard deviation, Sr0,9 0,7 0,5 1,8 1,3 1,1 Coefficient of variation of rep
