1、BS EN ISO2450:2008ICS 67.100.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDCream Determination of fatcontent Gravimetricmethod (Referencemethod) (ISO2450:2008)Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 18/05/2009 04:08, Uncontrolled Copy, (c) BSI
2、This British Standard was published under theauthority of the StandardsPolicy and StrategyCommittee on 31 January2009 BSI 2009ISBN 978 0 580 63535 9Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 2450:2008National forewordThis British Standard is the UK implementation of EN ISO
3、2450:2008. Itsupersedes BS EN ISO 2450:1999 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee AW/5, Chemical analysis of milk and milk products.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publicati
4、on does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 18/05/2009 04:08, Uncontrolled Copy, (c)
5、BSIEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 2450October 2008ICS 67.100.10 Supersedes EN ISO 2450:1999 English VersionCream - Determination of fat content - Gravimetric method(Reference method) (ISO2450:2008)Crme - Dtermination de la teneur en matire grasse -Mthode gravimtrique (Mthode d
6、e rfrence) (ISO2450:2008)Sahne - Bestimmung des Fettgehaltes - GravimetrischesVerfahren (Referenzverfahren) (ISO 2450:2008)This European Standard was approved by CEN on 14 October 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving
7、 this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions
8、 (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulga
9、ria, 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 United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZAT
10、IONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 2450:2008: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA ST
11、ANDARDS, 18/05/2009 04:08, Uncontrolled Copy, (c) BSIBS EN ISO 2450:2008EN ISO 2450:2008 (E) 3 Foreword This document (EN ISO 2450:2008) has been prepared by Technical Committee ISO/TC 34 “Agricultural food products“ in collaboration with Technical Committee CEN/TC 302 “Milk and milk products - Meth
12、ods of sampling and analysis”, the secretariat of which is held by NEN. 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 April 2009, and conflicting national standards shall be withdrawn at the lat
13、est by April 2009. 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 2450:1999. According to the CEN/CEN
14、ELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxem
15、bourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 2450:2008 has been approved by CEN as EN ISO 2450:2008 without any modification. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDAR
16、DS, 18/05/2009 04:08, Uncontrolled Copy, (c) BSIBS EN ISO 2450:2008ISO 2450:2008(E) IDF 16:2008(E) ISO and IDF 2008 All rights reserved iiiContents Page Foreword iv Foreword. v 1 Scope 1 2 Normative reference 1 3 Terms and definitions .1 4 Principle2 5 Reagents.2 6 Apparatus .2 7 Sampling.3 8 Prepar
17、ation of test sample4 9 Procedure .4 9.1 Test portion 4 9.2 Blank tests4 9.3 Preparation of fat-collecting vessel.5 9.4 Determination.5 10 Calculation and expression of results.7 10.1 Calculation7 10.2 Expression of results 8 11 Precision.8 11.1 Interlaboratory test 8 11.2 Repeatability.8 11.3 Repro
18、ducibility.8 12 Test report 8 Annex A (informative) Notes on procedures 9 Annex B (informative) Alternative procedure using fat-extraction tubes with siphon or wash-bottle fittings .11 Bibliography 14 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 18/05/2009 04:08, Uncontrolled Copy, (c) BSI
19、BS EN ISO 2450:2008ISO 2450:2008(E) IDF 16:2008(E) iv ISO and IDF 2008 All rights reservedForeword ISO (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 ou
20、t 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. ISO co
21、llaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International
22、Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the element
23、s of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 2450IDF 16 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF
24、). It is being published jointly by ISO and IDF. This fourth edition of ISO 2450IDF 16 cancels and replaces the third edition (ISO 2450:1999), of which it constitutes a minor revision. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 18/05/2009 04:08, Uncontrolled Copy, (c) BSIBS EN ISO 2450:2
25、008ISO 2450:2008(E) IDF 16:2008(E) ISO and IDF 2008 All rights reserved vForeword IDF (the International Dairy Federation) is a non-profit organization representing the dairy sector worldwide. IDF membership comprises National Committees in every member country as well as regional dairy associations
26、 having signed a formal agreement on cooperation with IDF. All members of IDF have the right to be represented at the IDF Standing Committees carrying out the technical work. IDF collaborates with ISO in the development of standard methods of analysis and sampling for milk and milk products. Draft I
27、nternational Standards adopted by the Action Teams and Standing Committees are circulated to the National Committees for voting. Publication as an International Standard requires approval by at least 50 % of the IDF National Committees casting a vote. Attention is drawn to the possibility that some
28、of the elements of this document may be the subject of patent rights. IDF shall not be held responsible for identifying any or all such patent rights. ISO 2450IDF 16 was prepared by the International Dairy Federation (IDF) and Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and
29、 milk products. It is being published jointly by IDF and ISO. All work was carried out by the Joint ISO-IDF Action Team Fat of the Standing Committee on Main components in milk under the aegis of its project leader, Mr G.J. Beutick (NL). This edition of ISO 2450IDF 16 cancels and replaces IDF 16:198
30、7, of which it constitutes a minor revision. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 18/05/2009 04:08, Uncontrolled Copy, (c) BSIBS EN ISO 2450:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 18/05/2009 04:08, Uncontrolled Copy, (c) BSIBS EN ISO 2450:2008INTERNATIONAL STAND
31、ARD ISO 2450:2008(E)IDF 16:2008(E) ISO and IDF 2008 All rights reserved 1Cream Determination of fat content Gravimetric method (Reference method) WARNING The use of this International Standard may involve hazardous materials, operations and equipment. This International Standard does not purport to
32、address all the safety problems associated with its use. It is the responsibility of the user of this International Standard to establish safety and health practices and determine the applicability of regulatory limitations prior to use. 1 Scope This International Standard specifies the reference me
33、thod for the determination of the fat content of raw, processed and sour cream in which no appreciable separation or breakdown of fat, due to lipolysis, has occurred. The method is not applicable to sour creams with starch or other thickening agents. NOTE If the method is not applicable and when sep
34、aration or breakdown of fat occurs, a method utilizing the Weibull-Berntrop principle is suitable (see ISO 8262-3|IDF 124-33). 2 Normative reference The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For un
35、dated references, the latest edition of the referenced document (including any amendments) applies. ISO 835, Laboratory glassware Graduated pipettes ISO 1042, Laboratory glassware One-mark volumetric flasks ISO 3889IDF 219, Milk and milk products Specification of Mojonnier-type fat extraction flasks
36、 ISO 4788, Laboratory glassware Graduated measuring cylinders 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 fat content of cream mass fraction of substances determined by the procedure specified in this International Standard NOTE The fat c
37、ontent is expressed as a percentage mass fraction. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 18/05/2009 04:08, Uncontrolled Copy, (c) BSIBS EN ISO 2450:2008ISO 2450:2008(E) IDF 16:2008(E) 2 ISO and IDF 2008 All rights reserved4 Principle An ammoniacal ethanolic solution of a test portio
38、n is extracted with diethyl ether and light petroleum. The solvents are removed by distillation or evaporation. The mass of the substances extracted is determined. NOTE This is usually known as the Rse-Gottlieb principle. 5 Reagents Use only reagents of recognized analytical grade, unless otherwise
39、specified, and only distilled or demineralized water or water of equivalent purity. The reagents shall leave no appreciable residue when the determination is carried out by the method specified (see 9.2.2). 5.1 Ammonia solution, containing a mass fraction of NH3of approximately 25 % (20= 910 g/l). N
40、OTE If ammonia solution of this concentration is not available, a more concentrated solution of known concentration may be used (see 9.4.2). 5.2 Ethanol (C2H5OH), or ethanol denatured by methanol, containing a volume fraction of ethanol of at least 94 %. (See Clause A.5.) 5.3 Congo red solution Diss
41、olve 1 g of Congo red (C32H22N6Na2O6S2) in water in a 100 ml one-mark volumetric flask (6.14). Make up to the mark with water. NOTE The use of this solution, which allows the interface between the solvent and aqueous layers to be seen more clearly, is optional (see 9.4.3). Other aqueous indicator so
42、lutions can be used provided that they do not affect the result of the determination. 5.4 Diethyl ether (C2H5OC2H5), free from peroxides (see Clause A.3), containing no more than 2 mg/kg of antioxidants, and complying with the requirements for the blank test (see 9.2.2, Clauses A.1 and A.4). WARNING
43、 The use of diethyl ether can lead to hazardous situations. Observe current safety precautions for handling, use, and disposal. 5.5 Light petroleum, with any boiling range between 30 C and 60 C or, as equivalent, pentane (CH3CH23CH3) with a boiling point of 36 C and complying with the requirements f
44、or the blank test (see 9.2.2, Clauses A.1 and A.4). The use of pentane is recommended because of its higher purity and consistent quality. 5.6 Mixed solvent Shortly before use, mix equal volumes of diethyl ether (5.4) and light petroleum (5.5). 6 Apparatus WARNING Since the determination involves th
45、e use of volatile flammable solvents, all electrical apparatus employed shall comply with legislation relating to the hazards in using such solvents. Usual laboratory equipment and, in particular, the following. 6.1 Analytical balance, capable of weighing to the nearest 1 mg, with a readability of 0
46、,1 mg. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 18/05/2009 04:08, Uncontrolled Copy, (c) BSIBS EN ISO 2450:2008ISO 2450:2008(E) IDF 16:2008(E) ISO and IDF 2008 All rights reserved 36.2 Centrifuge, capable of holding the fat-extraction flasks or tubes (6.6) and capable of spinning at a
47、rotational frequency of 500 min1to 600 min1to produce a radial acceleration of 80g to 90g at the outer end of the flasks or tubes. The use of the centrifuge is optional but recommended (see 9.4.6). 6.3 Distillation or evaporation apparatus, for distilling the solvents and ethanol from the boiling or
48、 conical flasks, or evaporating from beakers and dishes (see 9.4.13) at a temperature not exceeding 100 C. 6.4 Drying oven, electrically heated, with ventilation port(s) fully open, capable of being maintained at a temperature of 102 C 2 C throughout its working space. The oven shall be fitted with
49、a suitable thermometer. 6.5 Water bath, capable of being maintained at a temperature between 35 C and 50 C. 6.6 Mojonnier-type fat-extraction flasks, as specified in ISO 3889IDF 219. NOTE It is also possible to use fat-extraction tubes, with siphon or wash-bottle fittings, but then the procedure is different. The alternative procedure is given in Annex B. The fat-extraction flasks shall be provided with good quality cork bungs or stoppers of other material e.g. silicone rubber or polytetrafluoroethylene
