1、BSI Standards PublicationBS EN ISO 6886:2016Animal and vegetable fatsand oils Determination ofoxidative stability (acceleratedoxidation test) (ISO 6886:2016)BS EN ISO 6886:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 6886:2016.It supersedes BS EN ISO
2、 6886:2008 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee AW/307, Oilseeds, animal and vegetable fats and oils andtheir by-products.A list of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 n
3、ot purport to 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 91532 1ICS 67.200.10Compliance with a British Standard cannot confer immunity fromlegal obli
4、gations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 March 2016.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 6886 March 2016 ICS 67.200.10 Supersedes EN ISO 6886:2008Englis
5、h Version Animal and vegetable fats and oils - Determination of oxidative stability (accelerated oxidation test) (ISO 6886:2016) Corps gras dorigines animale et vgtale - Dtermination de la stabilit loxydation (essai doxydation acclr) (ISO 6886:2016) Tierische und pflanzliche Fette und le - Bestimmun
6、g der Oxidationsstabilitt (beschleunigter Oxidationstest) (ISO 6886:2016) This European Standard was approved by CEN on 13 February 2016. 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 nationa
7、l 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 member. This European Standard exists in three official versions (English, French, German). A versio
8、n 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. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Cze
9、ch 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 United Kingdom. E
10、UROPEAN 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 in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 6886:2016
11、 EBS EN ISO 6886:2016EN ISO 6886:2016 (E) 3 European foreword This document (EN ISO 6886:2016) has been prepared by Technical Committee ISO/TC 34 “Food products” in collaboration with Technical Committee CEN/TC 307 “Oilseeds, vegetable and animal fats and oils and their by-products - Methods of samp
12、ling 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 text or by endorsement, at the latest by September 2016, and conflicting national standards shall be withdrawn at the latest by
13、 September 2016. 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 responsible for identifying any or all such patent rights. This document supersedes EN ISO 6886:2008. According to the CEN-CENEL
14、EC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Ice
15、land, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 6886:2016 has been approved by CEN as EN ISO 6886:2016 without any modificatio
16、n. BS EN ISO 6886:2016ISO 6886:2016(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Reagents and materials . 26 Apparatus . 27 Sampling 38 Preparation of test sample and apparatus 58.1 Preparation of test sample 58.2 Preparation of apparatus . 58.2.1 Cleanin
17、g procedure 58.2.2 Determination of temperature correction . 69 Procedure. 610 Calculations 810.1 Manual calculation . 810.2 Automatic calculation . 811 Precision . 811.1 Results of interlaboratory test . 811.2 Repeatability . 811.3 Reproducibility . 812 Test report . 8Annex A (informative) Summary
18、of the method and examples of conductivity curves and the determination of induction time . 9Annex B (informative) Results of an interlaboratory test .11Bibliography .13 ISO 2016 All rights reserved iiiContents PageBS EN ISO 6886:2016ISO 6886:2016(E)ForewordISO (the International Organization for St
19、andardization) 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 committee has been established has the rig
20、ht 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 electrotechnical standardization.The procedures
21、 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 in accordance with the editorial rul
22、es 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 rights. Details of any patent rights ident
23、ified 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 constitute an endorsement.For an explanation
24、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 committee responsible for this document is
25、ISO/TC 34, Food products, Subcommittee SC 11, Animal and vegetable fats and oils.This third edition cancels and replaces the second edition (ISO 6886:2006), of which it constitutes a minor revision.iv ISO 2016 All rights reservedBS EN ISO 6886:2016INTERNATIONAL STANDARD ISO 6886:2016(E)Animal and ve
26、getable fats and oils Determination of oxidative stability (accelerated oxidation test)1 ScopeThis International Standard specifies a method for the determination of the oxidative stability of fats and oils under extreme conditions that induce rapid oxidation: high temperature and high air flow. It
27、does not allow determination of the stability of fats and oils at ambient temperatures, but it does allow a comparison of the efficacy of antioxidants added to fats and oils.The method is applicable to both virgin and refined animal and vegetable fats and oils. Milk and milk products (or fat coming
28、from milk and milk products) are excluded from the scope of this International Standard.NOTE The presence of volatile fatty acids and volatile acidic oxidation products prevents accurate measurement.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in thi
29、s 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 vegetable fats and oils Preparation of test sample3 Terms and defin
30、itionsFor the purposes of this document, the following terms and definitions apply.3.1induction periodtime between the start of the measurement and the time when the formation of oxidation products rapidly begins to increase3.2oxidative stabilityinduction period, expressed in hours, determined accor
31、ding to the procedure specified in this International StandardNote 1 to entry: A temperature of 100 C to 120 C is usually applied for the determination of oxidative stability. Depending on the oxidative stability of the sample under test, or when an extrapolation of regression is required, the deter
32、mination may be carried out at other temperatures. The optimal induction period is between 6 h to 24 h. A temperature increase or decrease of 10 C decreases or increases the induction period by a factor of approximately 2.3.3conductivityability of a material to conduct electric current4 PrincipleA s
33、tream of purified air is passed through the sample, which has been brought to a specified temperature. The gases released during the oxidation process, together with the air, are passed into a flask containing water that has been demineralized or distilled and contains an electrode for ISO 2016 All
34、rights reserved 1BS EN ISO 6886:2016ISO 6886:2016(E)measuring the conductivity. The electrode is connected to a measuring and recording device. The end of the induction period is indicated when the conductivity begins to increase rapidly. This accelerated increase is caused by the accumulation of vo
35、latile fatty acids produced during oxidation.5 Reagents and materialsUse only reagents of recognized analytical grade, and distilled or demineralized water.5.1 Molecular sieve, beads of approximately 1 mm diameter, pore size 0,3 nm, with moisture indicator.The molecular sieve should be dried in an o
36、ven set at 150 C and then cooled down to room temperature in a desiccator.5.2 Acetone.5.3 Alkaline cleaning solution, for laboratory glassware.5.4 Glycerol.5.5 Thermostable oil.6 ApparatusUsual laboratory equipment and, in particular, the following.6.1 Appliance for the determination of oxidative st
37、abilitySee Figures 1 and 2 for diagrammatic representations.NOTE An appliance for determining oxidative stability can be obtained commercially under the trade name Rancimat, from Metrohm AG, Herisau, Switzerland, or the OSI equipment from Omnion Inc., USA.1)6.1.1 Air filter, comprising a tube fitted
38、 with filter paper at each end and filled with molecular sieve (5.1), connected to the suction end of a pump.6.1.2 Gas diaphragm pump, with an adjustable flow rate of 10 l/h, in combination with an apparatus to control the flow rate, manually or automatically, with a maximum deviation of 1,0 l/h fro
39、m the set value.NOTE For the OSI instrument, a pressure of 5,5 psi is equivalent to a flow of approximately 10 l/h.6.1.3 Aeration vessels of borosilicate glass (usually eight), connected to a sealing cap.The sealing cap shall be fitted with a gas inlet and outlet tube. The cylindrical part of the ve
40、ssel shall preferably be narrower by a few centimetres below the top in order to break up any emerging foam. An artificial foam blocker (e.g. glass ring) may also be used for this purpose.6.1.4 Closed measurement cells (usually eight), of approximately 150 ml capacity, with a gas inlet tube extendin
41、g to the bottom inside of the vessel.The cell shall be provided at the top with ventilation holes.1) Rancimat () and OSI (Omnion) (http:/ are examples of suitable equipment available commercially. This information is given for the convenience of users of this document and does not constitute an endo
42、rsement by ISO of this equipment.2 ISO 2016 All rights reservedBS EN ISO 6886:2016ISO 6886:2016(E)6.1.5 Electrodes (usually eight), for measuring conductivity with a measuring range of 0 S/cm to 300 S/cm, aligned with the dimensions of the measurement cell (6.1.4).6.1.6 Measuring and recording appar
43、atus, comprising an amplifier and a recorder for registering the measuring signal of each of the electrodes (6.1.5).NOTE A computer-controlled central processing unit is used with Rancimat and OSI (Omnion).6.1.7 Certified and calibrated contact thermometer, graduated in 0,1 C, or Pt 100 element (pla
44、tinum resistance thermometer) to measure the block temperature, with attachments for a control relay connection and an adjustable heating element; temperature range 0 C to 150 C.6.1.8 Heating block, made of cast aluminium, adjustable to a temperature of up to 150 C 0,1 C.The block shall be provided
45、with holes (usually eight) for the aeration vessels (6.1.3), and an aperture for the contact thermometer (6.1.7).Alternatively, a heating bath may be used, filled with oil, suitable for temperatures up to 150 C and adjustable to the nearest 0,1 C.6.2 Certified and calibrated thermometer or Pt100 ele
46、ment, with a temperature range up to 150 C, graduated in 0,1 C.6.3 Measuring pipettes, of capacity 50 ml and 5 ml.6.4 Oven, capable of being maintained at a temperature of up to 150 C 3 C.6.5 Connecting hoses, flexible and made of inert material polytetrafluoroethylene Polytetrafluoroethylene (PTFE)
47、 or silicone.7 SamplingA representative sample should have been sent to the laboratory. It should not have been damaged or changed during transport or storage.Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 5555.1Store the sa
48、mple in the dark at about 4 C. ISO 2016 All rights reserved 3BS EN ISO 6886:2016ISO 6886:2016(E)Key1 air filter (6.1.1)2 gas diaphragm pump with flow rate control (6.1.2)3 aeration vessel (6.1.3)4 measurement cell (6.1.4)5 electrode (6.1.5)6 measuring and recording apparatus (6.1.6)7 thyristor and c
49、ontact thermometer (6.1.7)8 heating block (6.1.8)Figure 1 Diagrammatic representation of the apparatus4 ISO 2016 All rights reservedBS EN ISO 6886:2016ISO 6886:2016(E)Key1 air 5 aeration vessel2 measurement cell 6 sample3 electrode 7 heating block4 measuring solutionFigure 2 Diagrammatic representation of heating block, reaction vessel and measurement cell8 Preparation of test sample and apparatus8.1 Preparation of test samplePrepare the test sample in accordance with I
