1、BS EN ISO3093:2009ICS 67.060NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDWheat, rye andtheir flours, durumwheat and durumwheat semolina Determination ofthe falling numberaccording to Hagberg-Perten (ISO 3093:2009)This British Standardwas published under theau
2、thority of the StandardsPolicy and StrategyCommittee on 31 January2010 BSI 2010ISBN 978 0 580 67548 5Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 3093:2009National forewordThis British Standard is the UK implementation of EN ISO 3093:2009. Itsupersedes BS EN ISO 3093:2007 whi
3、ch is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee AW/4, Cereals and pulses.A list of organizations represented on this committee can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 publication does not purport to include all the necessary provisionsof a contract
4、. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 3093 December 2009 ICS 67.060 Supersedes EN ISO 3093:2007English Version Wheat, rye and their flours, durum whe
5、at and durum wheat semolina - Determination of the falling number according to Hagberg-Perten (ISO 3093:2009) Bls tendres, seigles et leurs farines, bls durs et leurs semoules - Dtermination de lindice de chute selon Hagberg-Perten (ISO 3093:2009) Weizen, Roggen und deren Mehl, Hartweizen und Hartwe
6、izengrie - Bestimmung der Fallzahl nach Hagberg-Perten (ISO 3093:2009) This European Standard was approved by CEN on 1 December 2009. 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 st
7、andard without any alteration. 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 oth
8、er language made by translation 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, Cyprus, Czech Republic, Denmark, Estonia
9、, 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. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPIS
10、CHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 3093:2009: EBS EN ISO 3093:2009EN ISO 3093:2009 (E) 3 Foreword This document (EN ISO 3093:2009) h
11、as been prepared by Technical Committee ISO/TC 34 “Food products“ in collaboration with 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 identica
12、l text or by endorsement, at the latest by June 2010, and conflicting national standards shall be withdrawn at the latest by June 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 not be held responsib
13、le for identifying any or all such patent rights. This document supersedes EN ISO 3093:2007. 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 Rep
14、ublic, 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. Endorsement notice The text of ISO 3093:2009 has b
15、een approved by CEN as a EN ISO 3093:2009 without any modification. BS EN ISO 3093:2009ISO 3093:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Principle2 5 Reagents.2 6 Apparatus.2 7 Sampling.3 8 Preparation of test sam
16、ple .3 8.1 Whole grain 3 8.2 Flour and semolina samples 4 9 Procedure.4 9.1 Determination of the moisture content .4 9.2 Test portion4 9.3 Determination of falling number 5 9.4 Calculation .6 10 Precision.7 10.1 Interlaboratory tests7 10.2 Repeatability 7 10.3 Reproducibility 7 11 Test report8 Annex
17、 A (normative) Equations for altitude correction of falling numbers .9 Annex B (informative) Results of interlaboratory tests 10 Bibliography13 BS EN ISO 3093:2009ISO 3093:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federati
18、on of national standards bodies (ISO member bodies). The work of preparing 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
19、. International organizations, governmental and non-governmental, in liaison 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 w
20、ith the rules given in the ISO/IEC Directives, Part 2. The main task of technical 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 appr
21、oval by at least 75 % of the member bodies casting a vote. ISO draws attention to the fact that it is claimed that compliance with this document may involve the use of a patent concerning the falling number apparatus specified in 6.1. ISO takes no position concerning the evidence, validity and scope
22、 of this patent right. The holder of this patent right has assured the ISO that he is willing to negotiate licences under reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this respect, the statement of the holder of this patent right is registered with
23、the ISO. Information may be obtained from: Perten Instruments AB P.O. Box 5101 S-141 05 HUDDINGE Sweden Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights other than those identified above. ISO shall not be held responsible for identi
24、fying any or all such patent rights. ISO 3093 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 4, Cereals and pulses. This fourth edition cancels and replaces the third edition (ISO 3093:2004), of which it constitutes a minor revision. It also incorporates the Technical
25、Corrigendum, ISO 3093:2004/Cor.1:2008. BS EN ISO 3093:2009INTERNATIONAL STANDARD ISO 3093:2009(E) ISO 2009 All rights reserved 1Wheat, rye and their flours, durum wheat and durum wheat semolina Determination of the falling number according to Hagberg-Perten 1 Scope This International Standard specif
26、ies the determination of the a-amylase activity of cereals by the falling number (FN) method according to Hagberg-Perten. This method is applicable to cereal grains, in particular to wheat and rye and their flours, durum wheat and its semolina. This method is not applicable to the determination of l
27、ow levels of a-amylase activity. By converting the FN into a liquefaction number (LN), it is possible to use this method to estimate the composition of mixtures of grain, flour or semolina with known FNs necessary to produce a sample of a required FN. 2 Normative references The following referenced
28、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 712, Cereals and cereal products Determination of moisture content Ref
29、erence method 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 apply. 3.1 falling number FN t total time required to activate a viscometer stirrer and allow it to fall a predete
30、rmined distance through an aqueous gel prepared from heating a mixture of flour or semolina, and water in a viscometer tube, and which is undergoing liquefaction due to attack by the enzyme a-amylase NOTE 1 Time is counted from immersion in the water bath. NOTE 2 The falling number is expressed in s
31、econds. BS EN ISO 3093:2009ISO 3093:2009(E) 2 ISO 2009 All rights reserved3.2 liquefaction number LN nLresult of a simple calculation to convert the falling number (3.1) into a value used to estimate the composition of mixtures of grain, flour or semolina necessary to produce a sample of the require
32、d falling number NOTE LNs, unlike FNs, are additive. 4 Principle The a-amylase activity is estimated using the starch present in the sample as a substrate. The determination is based on the ability of an aqueous suspension of flour, semolina or wholemeal cereal product to gelatinize rapidly in a boi
33、ling water bath, and on the measurement of starch liquefaction by the a-amylase present in the sample. Liquefaction affects the thickness of the starch gel and, hence, the resistance to the viscometer stirrer and the time taken for it to fall a defined distance. 5 Reagents 5.1 Water, produced by dis
34、tillation or demineralization, complying with ISO 3696, grade 3. 6 Apparatus Usual laboratory apparatus and, in particular, the following. 6.1 Apparatus for FN determination1), comprising the following components. 6.1.1 Water bath, with integral heating unit, cooling system and water level indicator
35、. 6.1.2 Electronic timer. 6.1.3 Viscometer stirrer, metallic, able to move freely within the ebonite stopper. Its rods shall be straight and the wheels free from distortion and wear. 6.1.4 Precision viscometer tubes, manufactured from special glass, with the following dimensions: inner diameter: 21,
36、00 mm 0,02 mm; outer diameter: 23,80 mm 0,25 mm; inner height: 220,0 mm 0,3 mm. 6.1.5 Rubber stoppers, to fit the viscometer tubes. 6.2 Automatic dispenser or pipette, ISO 8655-24, allowing a volume of 25,0 ml 0,2 ml to be delivered. 1) The “Falling Number” apparatus having a specifically designed v
37、iscometer stirrer produced by Perten Instruments is an example of a suitable device available commercially. This device forms the subject of a patent. This information is given for the convenience of users of this International Standard and does not constitute an endorsement by ISO of this product.
38、BS EN ISO 3093:2009ISO 3093:2009(E) ISO 2009 All rights reserved 36.3 Analytical balance, capable of being read to the nearest 0,01 g. 6.4 Laboratory mill2), hammer type, and fitted with a 0,8 mm screen allowing the production of a wholemeal product meeting the particle size specification shown in 8
39、.1.3. Check the performance of the mill periodically using a well-mixed sample of ground grain (as produced in 8.1.2). The mill may be equipped with an automatic feeding device, particularly for the grinding of high moisture content grain. 6.5 Laboratory sieve, of nominal size of openings 800 m, ISO
40、 5651and ISO 3310 (all parts)2. 7 Sampling Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 136905. A representative sample should have been sent to the laboratory. It should not have been damaged or changed during transport o
41、r storage. Storage time and storage conditions of the sample in the laboratory may have a significant effect on FNs. 8 Preparation of test sample 8.1 Whole grain 8.1.1 Elimination of impurities If necessary, clean the sample to eliminate impurities (e.g. stones, dust, husks and other cereal grains).
42、 Take a representative 300 g test sample from the laboratory sample. A smaller test sample of about 200 g, although it provides less reproducible results, may be used for routine inspections. If the sample is less than 200 g, the results risk being marred by errors. 8.1.2 Grinding of grain samples F
43、eed the laboratory mill (6.4) carefully with grain to avoid heating and overloading. The feed to the mill may be controlled automatically with an automatic feeding device. Grinding should be continued for 30 s to 40 s after the last of the sample has entered the mill. Discard the bran particles rema
44、ining inside the mill, provided these do not represent more than 1 % of the quantity of grain sampled for grinding. Thoroughly mix all of the milled product before use. It is recommended (especially in the case of successive grindings) to allow the meal to cool for 1 h before proceeding with the tes
45、t. 8.1.3 Ground sample specification WARNING FNs can be affected by the particle size of the ground grain. 2) LM 3100 and LM 120 mills are examples of suitable devices available commercially. This information is given for the convenience of users of this International Standard and does not constitut
46、e an endorsement by ISO of these products. BS EN ISO 3093:2009ISO 3093:2009(E) 4 ISO 2009 All rights reservedThe milled product shall comply with the specification given in Table 1. Table 1 Ground sample specification Nominal size of openings of sieve Amount of ground sample passing through sieve m
47、% 710 100 500 95 to 100 200 80 or less Check the particle size distribution of the ground material regularly using a well-mixed sample of ground grain (8.1.2). To do this, select the appropriate sieves, as specified in Table 1, and arrange in order of decreasing nominal size of openings with a suita
48、ble sieving aid in each sieve and a receiver pan on the bottom. Weigh out a representative sample of 50,0 g and place on the top sieve. Sieve in a horizontal plane, manually for at least 5 min until nothing passes through the 710 m sieve, or mechanically for a period of 10 min. Weigh the material re
49、tained on each sieve and that contained in the receiver pan. Calculate the percentage of ground grain which passes through each sieve. 8.2 Flour and semolina samples Flour samples shall not contain lumps. If necessary, sift the flour using the laboratory sieve (6.5) in order to remove lumps or foreign bodies. For coarse commercial wholemeal flours or semolina, grind a sample using the laboratory mill (6.4) in order to produce a test sample which conforms to the particle size specification shown in Table 1. Mix the gro
