1、BSI Standards PublicationBS EN ISO 3961:2013Animal and vegetable fats andoils Determination of iodinevalue (ISO 3961:2013)BS EN ISO 3961:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 3961:2013.It supersedes BS EN ISO 3961:2011 which is withdrawn.The U
2、K 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 include all the neces
3、saryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 79271 7ICS 67.200.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was p
4、ublished under the authority of theStandards Policy and Strategy Committee on 31 July 2013.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 3961 July 2013 ICS 67.200.10 Supersedes EN ISO 3961:2011English Version Animal and vegetable fats a
5、nd oils - Determination of iodine value (ISO 3961:2013) Corps gras dorigines animale et vgtale - Dtermination de lindice diode (ISO 3961:2013) Tierische und pflanzliche Fette und le - Bestimmung der Iodzahl (ISO 3961:2013) This European Standard was approved by CEN on 5 July 2013. CEN members are bo
6、und to comply with the CEN/CENELEC Internal Regulations 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
7、CEN-CENELEC 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 translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre
8、 has the same status as the official versions. 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,
9、 Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 201
10、3 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 3961:2013: EBS EN ISO 3961:2013EN ISO 3961:2013 (E) 3 Foreword This document (EN ISO 3961:2013) has been prepared by Technical Committee ISO/TC 34 “Food products“ in collaborati
11、on with 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 AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical tex
12、t or by endorsement, at the latest by January 2014, and conflicting national standards shall be withdrawn at the latest by January 2014. 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 responsi
13、ble for identifying any or all such patent rights. This document supersedes EN ISO 3961:2011. 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,
14、 Czech 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 Ki
15、ngdom. Endorsement notice The text of ISO 3961:2013 has been approved by CEN as EN ISO 3961:2013 without any modification. BS EN ISO 3961:2013ISO 3961:2013(E) ISO 2013 All rights reserved iiiContents PageForeword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Reagents
16、 16 Apparatus . 27 Sampling 28 Preparation of the test sample and test portion . 29 Procedure. 310 Calculation 411 Precision . 411.1 Interlaboratory test. 411.2 Repeatability limit, r 411.3 Reproducibility limit, R .412 Test report . 5Annex A (informative) Interlaboratory test 6Annex B (informative)
17、 Calculated iodine value for non-fish oils 8Bibliography .10BS EN ISO 3961:2013ISO 3961:2013(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 carrie
18、d 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 liaison with ISO, also take part in the work. IS
19、O collaborates closely with the International Electrotechnical Commission (IEC) 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
20、approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2, www.iso.org/directives.Attention is drawn to the possibility that some of the elements of this document may be the su
21、bject of patent rights. ISO shall not be held responsible for identifying 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, www.iso.org/patents.Any trade na
22、me used in this document is information given for the convenience of users and does not constitute an endorsement.The committee responsible for this document is ISO/TC 34, Food products, Subcommittee SC 11, Animal and vegetable fats and oils.This fifth edition cancels and replaces the fourth edition
23、 (ISO 3961:2009), which has been technically revised.iv ISO 2013 All rights reservedBS EN ISO 3961:2013INTERNATIONAL STANDARD ISO 3961:2013(E)Animal and vegetable fats and oils Determination of iodine value1 ScopeThis International Standard specifies a reference method for the determination of the i
24、odine value (commonly known in the industry as IV) of animal and vegetable fats and oils, hereinafter referred to as fats.Annex B describes a method for the calculation of the IV from fatty acid compositional data. This method is not applicable to fish oils. Furthermore cold-pressed, crude and unref
25、ined vegetable oils as well as (partially) hydrogenated oils can give different results by the two methods. The calculated IV is affected by impurities and thermal degradation products.NOTE The method in Annex B is based upon the AOCS Official method Cd 1c-85.92 Normative referencesThe following doc
26、uments, 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 661, Animal and veget
27、able fats and oils Preparation of test sample3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1iodine valueIVmass of halogen, expressed as iodine, absorbed by the test portion following the specified procedure, divided by the mass of the test port
28、ionNote 1 to entry: The IV is expressed as a mass fraction in grams per 100 g of fat.4 PrincipleDissolution of a test portion in solvent and addition of Wijs reagent. After a specified time, addition of potassium iodide and water, and titration of the liberated iodine with sodium thiosulfate solutio
29、n.NOTE Annex B describes a method for the calculation of the IV from fatty acid compositional data. However, this is not intended to be a rapid method. The method gives two results from one analytical procedure. The volumetric method is the reference method.5 ReagentsUse only reagents of recognized
30、analytical grade.WARNING Attention is drawn to the regulations which specify the handling of hazardous substances. Technical, organizational and personal safety measures shall be followed. Wijs solution causes severe burns; vapours can cause lung and eye damage. A fume hood shall be used for the wor
31、k. ISO 2013 All rights reserved 1BS EN ISO 3961:2013ISO 3961:2013(E)5.1 Water, in accordance with ISO 3696,4grade 3.5.2 Potassium iodide solution, mass concentration, (KI) = 100 g/l, not containing iodate or free iodine.5.3 Starch solution. Mix 5 g of soluble starch in 30 ml of water (5.1) and add t
32、o 1 000 ml of boiling water. Boil for 3 min and allow to cool. Prepare fresh starch solution every day.5.4 Sodium thiosulfate, standard volumetric solution, amount of substance concentration c(Na2S2O35H2O) = 0,1 mol/l, standardized not more than 7 days before use.5.5 Solvent, prepared by mixing one
33、volume of cyclohexane (50 ml) and one volume of glacial acetic acid (50 ml), volume fractions = 50 ml/100 ml.5.6 Wijs reagent, containing iodine monochloride in acetic acid. The I/Cl ratio of the Wijs reagent shall be within the limits 1,10 0,1. Wijs reagent is sensitive to temperature, moisture, an
34、d light. Store in the dark at 600,1111 Precision11.1 Interlaboratory testDetails of an interlaboratory test on the precision of the method are summarized in Annex A. It is possible that the values derived from this interlaboratory test are not applicable to concentration ranges and matrices other th
35、an those given.11.2 Repeatability limit, rThe repeatability limit, r, is the value less than or equal to which the absolute difference between two test results obtained under repeatability conditions may be expected to be with a probability of 95 %.Repeatability conditions are conditions where indep
36、endent test results are obtained with the same method on identical test items in the same laboratory by the same operator using the same equipment within short intervals of time.11.3 Reproducibility limit, RThe reproducibility limit, R, is the value less than or equal to which the absolute differenc
37、e between two test results obtained under reproducibility conditions may be expected to be with a probability of 95 %.Reproducibility conditions are conditions where independent test results are obtained with the same method on identical test items in different laboratories with different operators
38、using different equipment within short intervals of time.4 ISO 2013 All rights reservedBS EN ISO 3961:2013ISO 3961:2013(E)12 Test reportThe test report shall contain at least the following information:a) all information necessary for the complete identification of the sample;b) the sampling method u
39、sed, if known;c) the test method used, with reference to this International Standard (ISO 3961:2013);d) all operating details not specified in this International Standard, or regarded as optional, together with details of any incidents which may have influenced the test result(s);e) the test result(
40、s) obtained;f) if the repeatability has been checked, the final quoted result obtained. ISO 2013 All rights reserved 5BS EN ISO 3961:2013ISO 3961:2013(E)Annex A (informative) Interlaboratory testThe precision of the method has been established by an international interlaboratory test carried out in
41、accordance with ISO 5725.6The test was organized by DIN in 2011.The statistical results are given in Tables A.1 to A.3.Table A.1 Statistical results for the Wijs methodParameterSampleA B C D E F G HHardened vegetable oilCoconut oilButter fatPalm fat Olive oilRapeseed oilSun-flower seed oilFish oilNu
42、mber of participating labo-ratories15 18 19 19 19 19 19 19Number of laboratories retained after eliminating outliers12 15 17 16 17 17 16 18Number of individual test in all laboratories24 30 34 32 34 34 32 36Mean, wI, g/100 g0,78 8,33 32,99 51,18 81,5 113,1 124,9 199,1Repeatability standard devia-tio
43、n, sr, g/100 g0,07 0,07 0,17 0,21 0,6 0,8 0,6 1,1Coefficient of variation of repeatability, %9,1 0,9 0,5 0,4 0,7 0,7 0,5 0,6Repeatability limit, r (2,8 sr), g/100 g0,20 0,20 0,48 0,59 1,7 2,2 1,7 3,1Reproducibility standard deviation, sR, g/100 g0,11 0,13 0,55 0,50 1,2 1,4 1,4 5,5Coefficient of vari
44、ation of reproducibility, %14,6 1,6 1,7 1,0 1,5 1,2 1,1 2,7Reproducibility limit, R (2,8 sR), g/100 g0,32 0,36 1,54 1,40 3,4 3,9 3,9 15,36 ISO 2013 All rights reservedBS EN ISO 3961:2013ISO 3961:2013(E)Table A.2 Statistical results for the calculation from fatty acid composition (Annex B)ParameterSa
45、mpleA B C D E F GHardened vegetable oilCoconut oilButter fat Palm fat Olive oilRapeseed oilSun-flower seed oilNumber of participating labo-ratories18 18 18 18 18 18 18Number of laboratories retained after eliminating outliers17 15 16 16 18 14 15Number of individual test in all laboratories34 30 32 3
46、2 36 28 30Mean, wI, g/100 g0,22 8,61 30,16 51,49 80,3 111,3 124,5Repeatability standard devia-tion, sr, g/100 g0,04 0,09 0,17 0,32 0,3 0,2 0,3Coefficient of variation of repeatability, %16,6 1,0 0,6 0,6 0,4 0,2 0,2Repeatability limit, r (2,8 sr), g/100 g0,10 0,25 0,48 0,91 0,8 0,5 0,8Reproducibility
47、 standard deviation, sR, g/100 g0,23 0,87 1,85 1,00 1,6 0,6 0,7Coefficient of variation of reproducibility, %104,5 10,1 6,1 1,9 2,0 0,5 0,6Reproducibility limit, R (2,8 sR), g/100 g0,64 2,44 5,18 2,80 4,5 1,6 2,0Table A.3 Comparison of wI, r, R for both determination methodsParameterSampleA B C D E
48、F GHardened vegetable oilCoconut oilButter fatPalm fat Olive oilRapeseed oilSun-flower seed oilMean, wI, g/100 gWijs titration 0,78 8,33 32,99 51,18 81,5 113,1 124,9Calculation 0,22 8,61 30,16 51,49 80,3 111,3 124,5Difference 0,56 0,28 2,83 0,31 1,20 1,78 0,40Repeatability limit, r, g/100 gWijs titr
49、ation 0,20 0,20 0,48 0,59 1,7 2,2 1,7Calculation 0,10 0,25 0,48 0,91 0,8 0,5 0,8Reproducibility limit, R, g/100 gWijs titration 0,32 0,36 1,54 1,40 3,4 3,9 3,9Calculation 0,64 2,44 5,18 2,80 4,5 1,6 2,0 ISO 2013 All rights reserved 7BS EN ISO 3961:2013ISO 3961:2013(E)Annex B (informative) Calculated iodine value for non-fish oilsB.1 GeneralThis annex describes a method for calculating the IV of edible oils directly from fatty acid compositions determined by gas chromatography of methyl esters of fatty acids. It is applicable t
