EN ISO 14244-2016 en Oilseed meals - Determination of soluble proteins in potassium hydroxide solution《油籽粕-氢氧化钾溶液中可溶性蛋白质的测定(ISO 14244 2014)》.pdf

1、BS EN ISO 14244:2016Oilseed meals Determinationof soluble proteins inpotassium hydroxide solution(ISO 14244:2014)BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN ISO 14244:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN

2、 ISO 14244:2016.The UK participation in its preparation was entrusted to TechnicalCommittee AW/307, Oilseeds, animal and vegetable fats and oils andtheir by-products.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to

3、include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016. Published by BSI StandardsLimited 2016ISBN 978 0 580 92417 0ICS 67.200.20Compliance with a British Standard cannot confer immunity fromlegal obligations.This B

4、ritish Standard was published under the authority of theStandards Policy and Strategy Committee on 28 February 2014.Amendments/corrigenda issued since publicationDate Text affected31 August 2016 This corrigendum renumbers BS ISO 14244: 2014 as BS EN ISO 14244:2016It is identical to ISO 14244:2014. I

5、t supersedes BS ISO 14244:2014which is withdrawn.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 14244 August 2016 ICS 67.200.20 English Version Oilseed meals - Determination of soluble proteins in potassium hydroxide solution (ISO 14244:2014) Tourteaux de graines olagineuses - Dtermination

6、 de la teneur en protines solubles en solution dhydroxyde de potassium (ISO 14244:2014) lsamenschrote - Bestimmung der in Kaliumhydroxidlsung lslichen Proteine (ISO 14244:2014) This European Standard was approved by CEN on 15 July 2016. CEN members are bound to comply with the CEN/CENELEC Internal R

7、egulations which stipulate the conditions for giving this European Standard 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 m

8、ember. This European Standard exists in three official versions (English, 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

9、. CEN members are the national standards bodies of 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, Norway, Pola

10、nd, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, 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 2016 CEN All rights of exploitation

11、in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 14244:2016 EEN ISO 14244:2016 (E) European foreword The text of ISO 14244:2014 has been prepared by Technical Committee ISO/TC 34 “Food products” of the International Organization for Standardization (ISO) and

12、has been taken over as EN ISO 14244:2016 by Technical Committee CEN/TC 307 “Oilseeds, vegetable and animal fats and oils and their by-products - Methods of sampling and analysis” the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either

13、by publication of an identical text or by endorsement, at the latest by February 2017, and conflicting national standards shall be withdrawn at the latest by February 2017. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/o

14、r 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, Croatia, Cyprus, Czech

15、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, Switzerland, Turkey and the United Kingdom.

16、Endorsement notice The text of ISO 14244:2014 has been approved by CEN as EN ISO 14244:2016 without any modification. BS EN ISO 14244:2016iiISO 14244:2014(E) ISO 2014 All rights reserved iiiContents PageForeword iv1 Scope . 12 Normative references 13 Principle 14 Reagents 15 Apparatus . 26 Sampling

17、27 Preparation of test sample . 38 Procedure. 39 Expression of results 310 Precision . 410.1 Interlaboratory test. 410.2 Repeatability . 410.3 Reproducibility . 411 Test report . 4Annex A (informative) Results of interlaboratory tests 5Bibliography 6BS EN ISO 14244:2016ISO 14244:2014(E)ForewordISO (

18、the International Organization for Standardization) is a worldwide federation 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 commi

19、ttee has been established has the right to be represented on that committee. 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 electrotec

20、hnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted

21、 in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn 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 right

22、s. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitu

23、te an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe commit

24、tee responsible for this document is ISO/TC 34, Food products, Subcommittee SC 2, Oleaginous seeds and fruits and oilseed meals.iv ISO 2014 All rights reservedBS EN ISO 14244:2016INTERNATIONAL STANDARD ISO 14244:2014(E)Oilseed meals Determination of soluble proteins in potassium hydroxide solution1

25、ScopeThis International Standard specifies a method for the determination of soluble proteins in potassium hydroxide solution in soya meals, rapeseed meals and sunflower pellets, which are then assayed using the Kjeldahl method as specified in ISO 5983-1 and ISO 5983-2.2 Normative referencesThe foll

26、owing documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. 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 si

27、eves Metal wire cloth, perforated metal plate and electroformed sheet Nominal sizes of openingsISO 5500, Oilseed residues SamplingISO 5502, Oilseed residues Preparation of test samplesISO 5983-1, Animal feeding stuffs Determination of nitrogen content and calculation of crude protein content Part 1:

28、 Kjeldahl methodISO 5983-2, Animal feeding stuffs Determination of nitrogen content and calculation of crude protein content Part 2: Block digestion and steam distillation method3 PrincipleThe sample is dispersed in a solution of potassium hydroxide of approximately 12,5 pH, stirred and centrifuged.

29、 Then, the nitrogen content of the clarified liquid is determined by the Kjeldahl method for crude protein and compared with the value of crude protein of the original sample.NOTE The Kjeldahl method is described in ISO 5983-1 and ISO 5983-2.4 ReagentsWARNING 1 The tests, according to this Internati

30、onal Standard, involve risks for persons and the possibility of releasing substances which might cause damage to the environment. For this reason, appropriate measures shall be taken to prevent risk, protect personnel, and avoid the release of the substances involved.WARNING 2 Attention shall be pai

31、d to preserving the environment in all phases of this activity. For further information, it is recommended to make reference to ASTM D4447, which describes the classification of the kind of residues and pretreatment methods for their recovery or disposal.Use only reagents of recognized analytical gr

32、ade.4.1 Potassium hydroxide.4.2 Potassium hydroxide solution, c(KOH) = 0,036 mol/l.Preparation: Dissolve 2,4 g of potassium hydroxide (mass fraction w = 85 g/100 g) in 1 000 ml of distilled water. ISO 2014 All rights reserved 1BS EN ISO 14244:2016ISO 14244:2014(E)4.3 n-hexane or hexane mixed isomers

33、 or petroleum ether.5 ApparatusUsual laboratory apparatus and, in particular, the following.5.1 Sieve, 500 m for sunflower pellets and 250 m for soya and rapeseed meals (as specified in ISO 565).5.2 Analytical balance, capable of weighting to the nearest 0,001 g.5.3 Stirrers vessels, of 150 ml capac

34、ity.5.4 Magnetic stirrer with revolutions per minute (r/min) indicator or mechanical rotary stirrer, composed of an axis, and allowing the centrifuge tubes to invert totally as the axis rotates.5.5 Grinder.5.5.1 Cutting mill, type of coffee grinder or grinder equipped with a grid or equivalent.5.5.2

35、 Cyclone mill, or similar.5.6 Centrifuge, allowing reaching a relative acceleration of 800 g 100 g.The value of the rotational frequency, v, is calculated using Formula (1):vFd=423c(1)wherev is the rotational frequency, in revolutions per minute;d is the spinning diameter, in centimetres, measured b

36、etween the ends of the opposite tubes, in rotation position;Fcis the relative centrifugal acceleration (in this case, 800 g).5.7 One-mark volumetric pipettes, of 25 ml capacity.5.8 Burette, of 100 ml capacity.5.9 Centrifuge tube or centrifugation ampoule.5.10 Filter paper, nitrogen free or glass pot

37、, with a filter plate.6 SamplingSampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 5500.It is important that the laboratory receives a sample which is truly representative and has not been damaged or changed during transport or

38、storage.2 ISO 2014 All rights reservedBS EN ISO 14244:2016ISO 14244:2014(E)7 Preparation of test samplePrepare the test sample in accordance with ISO 5502.If the fat content of the sample is higher than 5 %, it shall be defatted by cold extraction using n-hexane.8 Procedure8.1 Carry out the determin

39、ation in duplicate.8.2 Grind the sample with a grinder or with any other apparatus which does not cause warming until it totally passes through a 250 m sieve for soya and rapeseed meals and through a 500 m sieve for sunflower pellets.Particle size greatly affects the final result of the analysis; th

40、erefore, it is recommended to carry out the milling with care.8.3 Weigh 1,5 g of the meal prepared as in 8.2, and place it in a 150 ml stirrers vessel. If a mechanical rotator stirrer is employed, the stirrers recipient should be used instead of the stirrers vessel.8.4 Add 75 ml (5.8) of potassium h

41、ydroxide solution (4.2) and stir at minimum speed for 20 min to maintain all the solids in suspension. If a stirrer is utilized, use the centrifuge tube with the stirring sets at minimum speed.8.5 Transfer the totality of the liquid to a centrifugal tube or centrifugation ampoule and centrifuge for

42、10 min at a relative acceleration of 800 g.8.6 If some particles are still in suspension, filter the clarified liquid through filter paper or a glass pot to prevent the possible transfer of particles.8.7 Take 25 ml (5.7) aliquots of filtrate and determine the nitrogen content by the Kjeldhal method

43、as described in ISO 5983-1 or ISO 5983-2.NOTE According to this procedure, each aliquot corresponds to 0,5 g of the original milled sample.8.8 The nitrogen content of the original milled sample shall be determined in duplicate using the Kjeldahl method as described in ISO 5983-1 or ISO 5983-2.9 Expr

44、ession of resultsThe content of soluble proteins in potassium hydroxide solution, wsp, expressed as a mass fraction, in grams of soluble proteins (from supernatant) per 100 g of the total protein, is calculated using Formula (2):wNNsp=st100 (2)wherewspis the soluble proteins content in potassium hyd

45、roxide solution, in grams per 100 g;Nsis the nitrogen content obtained as in 8.7;Ntis the nitrogen content obtained as in 8.8. ISO 2014 All rights reserved 3BS EN ISO 14244:2016ISO 14244:2014(E)Report the results to one decimal place.10 Precision10.1 Interlaboratory testThe results of an interlabora

46、tory test are given in Annex A for information.10.2 RepeatabilityThe absolute difference between two independent single test results, obtained using the same method on identical test materials in the same laboratory by the same operator using the same equipment within a short interval of time, will

47、not exceed the arithmetic mean of the values for r obtained from the interlaboratory study in more than 5 % of cases given in Table A.1.10.3 ReproducibilityThe absolute difference between two single test results, obtained using the same method on identical test materials in different laboratories wi

48、th different operators using different equipment will not exceed the arithmetic mean of the values for R obtained from the interlaboratory study in more than 5 % of cases given in Table A.1.11 Test reportThe test report shall specify: all information necessary for the complete identification of the

49、sample; the sampling method used, if known; the test method, with reference to this International Standard, i.e. ISO 14244; all operating details not specified in this International Standard, or regarded as optional, together with details of any incidents which might have influenced the results; the test results obtained; if the repeatability has been checked, the final quoted result obtained.4 ISO 2014 All rights reservedBS EN ISO 14244:2016ISO 14244:2014(E)Annex A (informative) Results of interlaboratory t