1、BSI Standards PublicationBS ISO 14244:2014Oilseed meals Determinationof soluble proteins inpotassium hydroxide solutionCopyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,
2、-BS ISO 14244:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 14244:2014.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 represent
3、ed on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 75001
4、 4ICS 67.200.20Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 28 February 2014.Amendments issued since publicationDate Text affectedCopyright British Standards In
5、stitution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS ISO 14244:2014 ISO 2014Oilseed meals Determination of soluble proteins in potassium hydroxide solutionTourteaux de graines olagineuses Dterminati
6、on de la teneur en protines solubles en solution dhydroxyde de potassiumINTERNATIONAL STANDARDISO14244First edition2014-02-15Reference numberISO 14244:2014(E)Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking
7、 permitted without license from IHS-,-,-BS ISO 14244:2014ISO 14244:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic o
8、r mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 74
9、9 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandCopyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS ISO 14244:2014ISO 14244:2
10、014(E) ISO 2014 All rights reserved iiiContents PageForeword iv1 Scope . 12 Normative references 13 Principle 14 Reagents 15 Apparatus . 26 Sampling 27 Preparation of test sample . 38 Procedure. 39 Expression of results 310 Precision . 410.1 Interlaboratory test. 410.2 Repeatability . 410.3 Reproduc
11、ibility . 411 Test report . 4Annex A (informative) Results of interlaboratory tests 5Bibliography 6Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS ISO 14244:2014IS
12、O 14244:2014(E)ForewordISO (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
13、 for which a technical committee 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)
14、on all matters of electrotechnical 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 note
15、d. This document was drafted 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
16、any or all such patent rights. 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
17、 users and does not constitute 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 - Supplem
18、entary informationThe committee 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 reservedCopyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for Resale
19、No reproduction or networking permitted without license from IHS-,-,-BS ISO 14244:2014INTERNATIONAL STANDARD ISO 14244:2014(E)Oilseed meals Determination of soluble proteins in potassium hydroxide solution1 ScopeThis International Standard specifies a method for the determination of soluble proteins
20、 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 following documents, in whole or in part, are normatively referenced in this document and are ind
21、ispensable 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 sieves Metal wire cloth, perforated metal plate and electroformed sheet Nominal sizes of openin
22、gsISO 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: Kjeldahl methodISO 5983-2, Animal feeding stuffs Determination of nitrogen content and calcu
23、lation 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. Then, the nitrogen content of the clarified liquid is determined by the Kjeldahl method for
24、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 International Standard, involve risks for persons and the possibility of releasing substances which mi
25、ght 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 paid to preserving the environment in all phases of this activity. For further information, it i
26、s 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 grade.4.1 Potassium hydroxide.4.2 Potassium hydroxide solution, c(KOH) = 0,036 mol/l.Preparatio
27、n: 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 1Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without licen
28、se from IHS-,-,-BS ISO 14244:2014ISO 14244:2014(E)4.3 n-hexane or hexane mixed isomers 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 bala
29、nce, capable of weighting to the nearest 0,001 g.5.3 Stirrers vessels, of 150 ml capacity.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 Cu
30、tting mill, type of coffee grinder or grinder equipped with a grid or equivalent.5.5.2 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 frequ
31、ency, in revolutions per minute;d is the spinning diameter, in centimetres, measured between 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 C
32、entrifuge tube or centrifugation ampoule.5.10 Filter paper, nitrogen free or glass pot, 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
33、which is truly representative and has not been damaged or changed during transport or storage.2 ISO 2014 All rights reservedCopyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IH
34、S-,-,-BS ISO 14244:2014ISO 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 determination in duplicate.8.2 Grind the sa
35、mple 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; therefore, it is recommended to carry
36、 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 hydroxide solution (4.2) and stir at
37、 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 10 min at a relative acceleration o
38、f 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 as described in ISO 5983-1 or ISO 5
39、983-2.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 Expression of resultsThe content of sol
40、uble 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 hydroxide solution, in grams per 100 g
41、;Nsis the nitrogen content obtained as in 8.7;Ntis the nitrogen content obtained as in 8.8. ISO 2014 All rights reserved 3Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-
42、,-,-BS ISO 14244:2014ISO 14244:2014(E)Report the results to one decimal place.10 Precision10.1 Interlaboratory testThe results of an interlaboratory test are given in Annex A for information.10.2 RepeatabilityThe absolute difference between two independent single test results, obtained using the sam
43、e method on identical test materials in the same laboratory by the same operator using the same equipment within a short interval of time, 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.1.10.3 Reproducibility
44、The absolute difference between two single test results, obtained using the same method on identical test materials in different laboratories with different operators using different equipment will not exceed the arithmetic mean of the values for R obtained from the interlaboratory study in more tha
45、n 5 % of cases given in Table A.1.11 Test reportThe test report shall specify: all information necessary for the complete identification of the sample; the sampling method used, if known; the test method, with reference to this International Standard, i.e. ISO 14244; all operating details not specif
46、ied 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 reservedCopyright British Standards In
47、stitution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS ISO 14244:2014ISO 14244:2014(E)Annex A (informative) Results of interlaboratory testsAn interlaboratory test was carried out by the Argentinean C
48、ertification and Standardization Institute (IRAM) in order to evaluate the repeatability and reproducibility of the test method in this International Standard.Ten test samples of three different matrixes (soybean meal, rapeseed meal and sunflower pellets) were sent to 24 national and foreign laboratories, and 21 laboratories results were received. To sum up, 87,5 % of laboratories participated actively in this interlaboratory test.The calculation of repeatability and reproducibility values obtained for soluble proteins arises
