DIN EN ISO 8292-2-2010 Animal and vegetable fats and oils - Determination of solid fat content by pulsed NMR - Part 2 Indirect method (ISO 8292-2 2008) German version EN ISO 8292-2.pdf

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1、August 2010 Translation by DIN-Sprachendienst.English price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS

2、 67.200.10!$j9“1712922www.din.deDDIN EN ISO 8292-2Animal and vegetable fats and oils Determination of solid fat content by pulsed NMR Part 2: Indirect method (ISO 8292-2:2008)English translation of DIN EN ISO 8292-2:2010-08Tierische und pflanzliche Fette und le Bestimmung des Festanteils von Fett du

3、rch das Verfahren mit gepulster magnetischerKernresonanz Teil 2: Indirektes Verfahren (ISO 8292-2:2008)Englische bersetzung von DIN EN ISO 8292-2:2010-08Corps gras dorigines animale et vgtale Dtermination de la teneur en corps gras solides par RMN pulse Partie 2: Mthode indirecte (ISO 8292-2:2008)Tr

4、aduction anglaise de DIN EN ISO 8292-2:2010-08www.beuth.deIn case of doubt, the German-language original shall be considered authoritative.Document comprises 23 pagesTogether with DIN EN ISO8292-1:2010-08,supersedesDIN EN ISO 8292:1995-0708.10 DIN EN ISO 8292-2:2010-08 2 A comma is used as the decim

5、al marker. National foreword This standard has been prepared by Technical Committee ISO/TC 34 “Food products” (Secretariat: AFNOR, France), Subcommittee SC 11 “Animal and vegetable fats and oils” (Secretariat: BSI, United Kingdom) in collaboration with Technical Committee CEN/TC 307 “Oilseeds, veget

6、able and animal fats and oils and their by-products Methods of sampling and analysis” (Secretariat: AFNOR, France). The responsible German bodies involved in its preparation were the Normenausschuss Lebensmittel und landwirtschaftliche Produkte (Food and Agricultural Products Standards Committee) an

7、d the Deutsche Gesellschaft fr Fettwissenschaft DGF (German Fat Research Society), Joint Committee NA 057-05-05 AA Analytik von Fetten, len, Fettprodukten, verwandten Stoffen und Rohstoffen. DIN EN ISO 8292 consists of the following parts, under the general title Animal and vegetable fats and oils D

8、etermination of solid fat content by pulsed NMR: Part 1: Direct method Part 2: Indirect method The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 661 DIN EN ISO 661 ISO 3960 DIN EN ISO 3960 ISO 5555 DIN EN ISO 5555 ISO 5725-1 DIN ISO 5725-

9、1 ISO 5725-2 DIN ISO 5725-2 ISO 8292-1 DIN EN ISO 8292-1 Amendments This standard differs from DIN EN ISO 8292:1995-07 as follows: a) The standard has been divided into two parts: Part 1 specifying a direct method and Part 2 specifying an indirect method for the determination of the solid fat conten

10、t. b) The scope now specifies an indirect method for the determination of the solid fat content in animal and vegetable fats and oils using low-resolution pulsed nuclear magnetic resonance (NMR) spectrometry. c) Requirements for the apparatus (7), sampling (8), procedure (9), expression of results (

11、10), precision (11) and the test report (12) for the indirect method have been specified. d) Annex A (informative) “Results of interlaboratory tests” has been added. e) Annex B (informative) “Theory of indirect method” has been added. f) Annex C informative) “Additional measurement protocols” has be

12、en added. g) The standard has been editorially revised. Previous editions DIN EN ISO 8292: 1995-07 DIN EN ISO 8292-2:2010-08 3 National Annex NA (informative) Bibliography DIN EN ISO 661, Animal and vegetable fats and oils Preparation of test sample DIN EN ISO 3960, Animal and vegetable fats and oil

13、s Determination of peroxide value Iodometric (visual) endpoint determination DIN EN ISO 5555, Animal and vegetable fats and oils Sampling DIN ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results Part 1: General principles and definitions DIN ISO 5725-2, Accuracy (trueness

14、 and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method DIN EN ISO 8292-1, Animal and vegetable fats and oils Determination of solid fat content by pulsed NMR Part 1: Direct method DIN EN ISO

15、8292-2:2010-08 4 This page is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 8292-2 April 2010 ICS 67.200.10 Supersedes EN ISO 8292:1995English Version Animal and vegetable fats and oils - Determination of solid fat content by pulsed NMR - Part 2: Indirect method (ISO 8

16、292-2:2008) Corps gras dorigines animale et vgtale - Dtermination de la teneur en corps gras solides par RMN pulse - Partie 2: Mthode indirecte (ISO 8292-2:2008) Tierische und pflanzliche Fette und le - Bestimmung des Festanteils von Fett durch das Verfahren mit gepulster magnetischer Kernresonanz -

17、 Teil 2: Indirektes Verfahren (ISO 8292-2:2008) This European Standard was approved by CEN on 18 March 2010. 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 standard without any altera

18、tion. 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 other language made by trans

19、lation 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, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Franc

20、e, 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 EUROPISCHES KOMITEE FR

21、NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 8292-2:2010: EContents EN ISO 8292-2:2010 (E) DIN EN ISO 8292-2:2010-08 2 Page Foreword3 1 Scope 4 2 Normative re

22、ferences 4 3 Terms and definitions .4 4 Symbols and abbreviated terms 5 5 Principle5 6 Triolein standard sample 5 7 Apparatus .5 8 Sampling.7 9 Procedure .7 9.1 Measurement protocol and test sample7 9.2 Oven, water baths and temperature-controlled blocks .7 9.3 NMR spectrometer.7 9.4 Filling the mea

23、surement tubes.7 9.5 Removing the thermal history9 9.6 Equilibrating at the initial temperature and measuring the 100 % liquid signal .9 9.7 Crystallization and tempering 9 9.8 Measuring the SFC 9 9.9 Number of determinations 10 9.10 Cleaning the measurement tubes 10 10 Expression of results 10 11 P

24、recision.11 11.1 Interlaboratory test 11 11.2 Repeatability.11 11.3 Reproducibility.11 12 Test report 11 Annex A (informative) Results of interlaboratory tests.12 Annex B (informative) Theory of indirect method15 Annex C (informative) Additional measurement protocols17 Bibliography 19 Foreword The t

25、ext of ISO 8292-2:2008 has been prepared by Technical Committee ISO/TC 34 “Food products” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 8292-2:2010 by Methods of sampling and analysis” the secretariat of which is held by AFNOR. This European Standard s

26、hall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2010, and conflicting national standards shall be withdrawn at the latest by October 2010. Attention is drawn to the possibility that some of the elements of this d

27、ocument 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 8292:1995. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries a

28、re bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, S

29、pain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 8292-2:2008 has been approved by CEN as a EN ISO 8292-2:2010 without any modification. Technical Committee CEN/TC 307 “Oilseeds, vegetable and animal fats and oils and their by-products EN ISO 8292-2:2010 (E) DIN EN

30、 ISO 8292-2:2010-08 3 1 Scope This part of ISO 8292 specifies an indirect method for the determination of the solid fat content in animal and vegetable fats and oils (hereafter designated “fats”) using low-resolution pulsed nuclear magnetic resonance (NMR) spectrometry. Two alternative thermal pre-t

31、reatments are specified: one for general purpose fats not exhibiting pronounced polymorphism and which stabilize mainly in the -polymorph; and one for fats similar to cocoa butter which exhibit pronounced polymorphism and stabilize in the -polymorph. Additional thermal pre-treatments, which may be m

32、ore suitable for specific purposes, are given in an informative annex. The indirect method is less easy to carry out and less reproducible than the direct method, but is more accurate and more universally applicable to all fats. NOTE A direct method is specified in ISO 8292-1. 2 Normative references

33、 The following referenced 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 661, Animal and vegetable fats and oils Prep

34、aration of test sample ISO 3960, Animal and vegetable fats and oils Determination of peroxide value Iodometric (visual) endpoint determination ISO 8292-1, Animal and vegetable fats and oils Determination of solid fat content by pulsed NMR Part 1: Direct method 3 Terms and definitions For the purpose

35、s of this document, the terms and definitions given in ISO 8292-1 apply. EN ISO 8292-2:2010 (E) DIN EN ISO 8292-2:2010-08 4 4 Symbols and abbreviated terms f conversion (extrapolation) factor to correct the NMR signal observed at 11 s to that at time zero npnumber of pulses S1magnetization decay sig

36、nal measured at about 11 s S2magnetization decay signal measured at about 70 s SFC solid fat content SLmagnetization decay signal corresponding to the liquid phase SSmagnetization decay signal corresponding to the solid phase SS+Lmagnetization decay signals corresponding to both solid and liquid pha

37、ses treprepetition time wSFC,i“true” SFC (measured in accordance with this part of ISO 8292) wSFC,TSFC at measurement temperature, T 5 Principle The sample is tempered to a stable state at a specific temperature and then heated to, and stabilized at, the measurement temperature. Unless otherwise spe

38、cified, measurement temperatures can be any or all of: 0 C; 5 C; 10 C; 15 C; 20 C; 25 C; 27,5 C; 30 C; 32,5 C; 35 C; 37,5 C; 40 C; 45 C; 50 C; 55 C; 60 C. After electromagnetic equilibration in the static magnetic field of the NMR spectrometer and application of a 90 radio frequency pulse, the magne

39、tization decay signal from the protons in the liquid phase only is measured and the solid fat calculated by reference to a standard sample consisting entirely of liquid fat. Provided that the liquid fat measurements have been made at the start of the SFC determination, results can be displayed immed

40、iately as in the direct method. 6 Triolein standard sample The liquid fat standard sample shall contain a minimum 99 % mass fraction of triolein. The peroxide value determined according to ISO 3960 shall be less than 5. Store triolein stocks at a temperature below 0 C. Store reference tubes containi

41、ng triolein in a refrigerator at 0 C to 8 C when not in use, and replace them every 2 weeks. 7 Apparatus 7.1 Pulsed nuclear magnetic resonance (NMR) spectrometer, low resolution The NMR spectrometer shall have: a) a magnet with a sufficiently uniform field to ensure that the half-life of the magneti

42、zation of a reference sample of liquid fat is longer than 1 000 s; b) an automatic measuring device which operates as soon as the measurement tubes (7.2) are inserted; c) an adjustable measurement repetition time; d) a 10 mm measurement cell/probe for test portion tubes which is temperature-controll

43、ed at 40 C. For preference, the instrument should be equipped with a computer which automatically takes the required measurements, performs the required calculations and presents the results directly on the computer screen or other display. EN ISO 8292-2:2010 (E) DIN EN ISO 8292-2:2010-08 5 7.2 Meas

44、urement tubes Made of glass with plastic caps, with outer diameter (10 0,25) mm, wall thickness (0,9 0,25) mm, and length at least 150 mm, or as specified by the NMR spectrometer manufacturer. 7.3 Temperature-maintenance equipment 7.3.1 General In principle, temperature-controlled blocks have advant

45、ages over water baths because the tubes can never come into contact with water. In practice, as with aluminium blocks in water baths, the tubes may take a significant time to come to the set temperature. Heat transfer can be improved if the tube wells are purged with a dry gas. Blocks are also more

46、difficult to control precisely than water baths, although modern electronic controls may provide the required precision. 7.3.2 Water baths Baths are required at temperatures of (0 0,1) C, (60 0,1) C, and, to within 0,1 C, the measuring and tempering temperatures required according to the measurement

47、 protocol chosen. For the 60 C, measurement temperature, and tempering temperature baths, temperature-controlled blocks (7.3.3) may be substituted. Each water bath shall be equipped with either one aluminium block (7.3.2.1) or one metal rack (7.3.2.2) to accommodate measurement tubes (7.2) immersibl

48、e in the water to a depth of 60 mm. Metal racks are preferred to aluminium blocks, especially when a large number of test samples with high SFC are being measured or when the rapid or ultra-rapid measurement protocols are being used. When using aluminium blocks, there may be a significant time lag a

49、fter the tube is inserted before the fat in the tube reaches the set temperature of the water bath. The perceived advantage of blocks is that the tubes can remain dry and do not need to be wiped dry with a paper tissue before insertion into the spectrometer. In practice, however, it is usually found that due to splashing or condensation, the tubes do become wet so that drying is always recommended, see Clause 9. 7.3.2.1 Aluminium blocks, with holes of diameter (10,35 0,1) mm