1、December 2011 Translation by DIN-Sprachendienst.English price group 10No 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).I
2、CS 67.200.10!$xXu“1855382www.din.deDDIN EN ISO 17932Palm oil Determination of the deterioration of bleachability index (DOBI) andcarotene content (ISO 17932:2011)English translation of DIN EN ISO 17932:2011-12Palml Bestimmung des Bleichindex zur Beurteilung der Qualitt von rohem Palml (DOBIDeteriora
3、tion of bleachability index) sowie des Carotingehaltes (ISO 17932:2011)Englische bersetzung von DIN EN ISO 17932:2011-12Huile de palme Dtermination de la dtrioration de lindice de blanchiment (DOBI) et de la teneur encarotne (ISO 17932:2011)Traduction anglaise de DIN EN ISO 17932:2011-12SupersedesDI
4、N EN ISO 17932:2007-10www.beuth.deDocument comprises 15 pagesIn case of doubt, the German-language original shall be considered authoritative.12.11 DIN EN ISO 17932:2011-12 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee ISO/TC 34 “Fo
5、od products” in collaboration with Technical Committee CEN/TC 307 “Oilseeds, vegetable 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 la
6、ndwirtschaftliche Produkte (Foodstuffs and Agricultural Products Standards Committee) and the Deutsche Gesellschaft fr Fettforschung (German Fat Research Society), Joint Committee Gemeinschaftsausschuss fr die Analytik von Fetten, len, Fettprodukten, verwandten Stoffen und Rohstoffen. The DIN Standa
7、rds corresponding to the International Standards referred to in this document are as follows: ISO 661 DIN EN ISO 661 ISO 1042 DIN EN ISO 1042 ISO 5555 DIN EN ISO 5555 ISO 5725-1 DIN ISO 5725-1 ISO 5725-2 DIN ISO 5725-2 ISO/IEC 17025 DIN EN ISO/IEC 17025 Amendments This standard differs from DIN EN I
8、SO 17932:2007-10 as follows: a) the title of the standard has been modified; b) Clause 1 “Scope” has been extended; c) Clause 2 “Normative references” has been extended (ISO/IEC 17025 and ISO Guide 34 have been added); d) in Clause 3 “Terms and definitions”, 3.2 “carotene content of vegetable oil” h
9、as been added; e) in Subclause 6.1 “Spectrometer”, items a) “Wavelength scale” and b) “Absorbance scale” have been updated and rendered more precise; f) Subclause 6.4 “Analytical balance” has been added; g) Clause 7 “Sampling” has been given in more detail; h) Clause 10 “Calculation” has been subdiv
10、ided; i) Annex B (informative) “Results of an interlaboratory test on carotene content” has been added; j) the Bibliography has been updated and extended; k) the standard has been editorially revised. Previous editions DIN EN ISO 17932: 2007-10 DIN EN ISO 17932:2011-12 3 National Annex NA (informati
11、ve) Bibliography DIN EN ISO 661, Animal and vegetable fats and oils Preparation of test sample DIN EN ISO 1042, Laboratory glassware One-mark volumetric flasks DIN EN ISO 5555, Animal and vegetable fats and oils Sampling DIN EN ISO/IEC 17025, General requirements for the competence of testing and ca
12、libration laboratories 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 and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and
13、reproducibility of a standard measurement method DIN EN ISO 17932:2011-12 4 This page is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 17932 September 2011 ICS 67.200.10 Supersedes EN ISO 17932:2007English Version Palm oil - Determination of the deterioration of bleach
14、ability index (DOBI) and carotene content (ISO 17932:2011) Huile de palme - Dtermination de la dtrioration de lindice de blanchiment (DOBI) et de la teneur en carotne (ISO 17932:2011) Palml - Bestimmung des Bleichindex zur Beurteilung der Qualitt von rohem Palml (DOBI Deterioration of bleachability
15、index) sowie des Carotingehaltes (ISO 17932:2011) This European Standard was approved by CEN on 14 September 2011. 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
16、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 version in any other language
17、 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, Czech Republic, Denmark, E
18、stonia, Finland, France, 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 E
19、UROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 17932:2011: EContents Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definit
20、ions .4 4 Principle4 5 Reagents.4 6 Apparatus .5 7 Sampling.6 8 Preparation of test sample6 9 Procedure .6 9.1 General6 9.2 Test portion and preparation of the test solution 6 9.3 Determination.6 10 Calculation6 11 Precision.7 11.1 Interlaboratory test 7 11.2 Repeatability.7 11.3 Reproducibility.7 1
21、2 Test report 7 Annex A (informative) Results of an interlaboratory test on DOBI 9 Annex B (informative) Results of an interlaboratory test on carotene content10 Bibliography 11 DIN EN ISO 17932:2011-12 EN ISO 17932:2011 (E) 2 Foreword This document (EN ISO 17932:2011) has been prepared by Technical
22、 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 sampling and analysis” the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national st
23、andard, either by publication of an identical text or by endorsement, at the latest by March 2012, and conflicting national standards shall be withdrawn at the latest by March 2012. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights.
24、CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 17932:2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard
25、: 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, Spain, Sweden, Switzerland and the United Kin
26、gdom. Endorsement notice The text of ISO 17932:2011 has been approved by CEN as a EN ISO 17932:2011 without any modification. DIN EN ISO 17932:2011-12 EN ISO 17932:2011 (E) 3 1 ScopeThis International Standard specifies a method for the determination of the deterioration of bleachability index (DOBI
27、) of crude palm oil and the carotene content of crude or bleached palm oil and their fractions by spectrophotometric examination in the ultraviolet and visible range of the spectrum.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For d
28、ated 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 sampleISO/IEC 17025, General requirements for the competence of testing and calibr
29、ation laboratoriesISO Guide 34, General requirements for the competence of reference material producers3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1deterioration of bleachability indexDOBIIDoBratio of the absorbance of the test portion at 446
30、 nm to that at 269 nm, as determined spectrophotometrically in a 10 mm (1 cm) pathlength cellNOTE DOBI is expressed to one decimal place without a dimension.3.2carotene content of vegetable oilwcmass fraction of -carotene in oilNOTE The carotene content of vegetable oil is expressed in milligrams pe
31、r kilogram.4 PrincipleA homogenized sample is dissolved in isooctane and the absorbance is measured spectrophotometrically at 446 nm and 269 nm. The DOBI value is the ratio of the absorbance at 446 nm to that at 269 nm. The test is a measure of the ease of refining crude palm oil. A low DOBI value c
32、an indicate difficulty in refining the oil to a low Lovibond colour. The absorbance at 446 nm is used for calculation of the carotene content.5 ReagentsWARNING Attention is drawn to the regulations which specify the handling of dangerous substances. Technical, organizational and personal safety meas
33、ures shall be followed.DIN EN ISO 17932:2011-12 EN ISO 17932:2011 (E) 4 During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and distilled or demineralized water or water of equivalent purity.5.1 Solvent: isooctane (2,2,4-trimethylpentane), having an absorba
34、nce less than 0,12 at 230 nm and less than 0,05 at 250 nm against water, measured in a cell with a pathlength of 10 mm (1 cm).6 ApparatusThe glassware used for the determination shall be thoroughly cleaned and rinsed with the solvent (5.1) before use, so that it is free from impurities having an abs
35、orbance within the wavelength range of 220 nm to 500 nm.Usual laboratory apparatus and, in particular, the following.6.1 Spectrometer, capable of operating in the ultraviolet and visible range and using 10 mm (1 cm) pathlength quartz cells and preferably having a recording instrument.Before use, it
36、is recommended that the wavelength and absorbance scales of the spectrometer be checked as follows.a) Wavelength scale: This may be checked using a reference material consisting of an optical glass filter containing holmium oxide which has distinct absorption bands. The reference material is designe
37、d for the verification and calibration of the wavelength scales of visible and ultraviolet spectrophotometers having nominal spectral bandwidths of 5 nm or less. The holmium glass filter is measured in the absorbance mode against an air blank over the wavelength range of 640 nm to 240 nm. For each s
38、pectral bandwidth (0,10 0,25 0,50 1,00 1,50 2,00 and 3,00), a baseline correction is performed with an empty cell holder. The wavelengths of the spectral bandwidth are listed in the certificate of the reference material1). All procedures shall be implemented in accordance with ISO/IEC 17025 and ISO
39、Guide 34.b) Absorbance scale: Secondary calibration standards can be used to check the ordinate accuracy. The set of standards consisting of gray glass filters2)provide nominal absorbance, A, values of 0,3A, 0,5A, and 1,0A respectively. The ordinate readings of the filters are measured at each of th
40、e selected wavelengths and the readings obtained compared with those listed in the certificate of the secondary calibration standards.Alternatively, prepare a 200 mg/l solution of potassium chromate3)in 0,05 mol/l potassium hydroxide solution. Transfer 25 ml of this solution to a volumetric flask, c
41、apacity 500 ml, ISO 10421, class A, and make up to the mark with additional 0,05 mol/l potassium hydroxide solution. The absorbance of this solution, measured in a cell 10 mm thick at 275 nm against the 0,05 mol/l potassium hydroxide solution, should be 0,200 0,005.WARNING Potassium chromate is very
42、 toxic, dangerous to the environment and a carcinogen by inhalation. Attention is drawn to regulations which specify handling and disposal procedures for toxic and dangerous substances. Users should be aware of and comply with technical, organizational, and personal safety measures.6.2 Matched quart
43、z cells, of pathlength 10 mm (1 cm), suitable for measurements at ultraviolet and visible wavelengths.6.3 Volumetric flask, capacity 25 ml, ISO 10421, class A.6.4 Analytical balance, capable of being read to the nearest 0,001 g.1) Starna Scientific Ltd () is an example of a supplier of suitable holm
44、ium filters and potassium dichromate sealed cell available commercially. This information is given for the convenience of users of this document and does not constitute an endorsement by ISO of these products.2) A suitable supplier is PerkinElmer Ltd. This information is given for the convenience of
45、 users of this document and does not constitute an endorsement by ISO of the supplier named.3) NIST 935a is an example of a suitable product available commercially. This information is given for the convenience of users of this document and does not constitute an endorsement by ISO of the product na
46、med.DIN EN ISO 17932:2011-12 EN ISO 17932:2011 (E) 5 7 SamplingSampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 55552.A representative sample should have been sent to the laboratory. It should not have been damaged or changed
47、during transport or storage.Ensure that the sample is taken and stored away from strong light, kept cold and contained in completely filled glass containers, hermetically sealed with ground glass or waxed cork stoppers.8 Preparation of test samplePrepare the test sample in accordance with ISO 661.9
48、Procedure9.1 GeneralMelt the sample at 60 C to 70 C and homogenize thoroughly before taking a test portion. Filter through a fast filter paper Whatman No. 14) if the sample contains impurities and is not clear.9.2 Test portion and preparation of the test solutionWeigh, to the nearest 0,1 mg, about 0,1 g to 0,5 g of the test sample (Clause 8), sufficient to obtain absorbance values between 0,2 and 0,8, into a 25 ml volumetric flask (6.3).Dissolve the test portion in a few millil
