BS EN ISO 1735-2004 Cheese and processed cheese products - Determination of fat content - Gravimetric method (Reference method)《干酪及融化干酪制品 脂肪含量的测定 重量法(参照法)》.pdf

1、BRITISH STANDARD BS EN ISO 1735:2004 Cheese and processed cheese products Determination of fat content Gravimetric method (Reference method) The European Standard EN ISO 1735:2004 has the status of a British Standard ICS 67.100.30 BS EN ISO 1735:2004 This British Standard was published under the aut

2、hority of the Standards Policy and Strategy Committee on 14 July 2004 BSI 14 July 2004 ISBN 0 580 44091 5 National foreword This British Standard is the official English language version of EN ISO 1735:2004. It is identical with ISO 1735:2004. It supersedes BS 770-3:1989 which is withdrawn. The UK p

3、articipation in its preparation was entrusted to Technical Committee AW/5, Milk and milk products, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international

4、or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to in

5、clude all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enq

6、uiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword

7、page, the ISO title page, pages ii to v, a blank page, pages 1 to 15 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO1735 J

8、uly2004 ICS67.100.30 Englishversion CheeseandprocessedcheeseproductsDeterminationoffat contentGravimetricmethod(Referencemethod)(ISO 1735:2004) FromagesetfromagesfondusDterminationdelateneur enmatiregrasseMthodegravimtrique(Mthodede rfrence)(ISO1735:2004) ThisEuropeanStandardwasapprovedbyCENon1June2

9、004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariator

10、toanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodies

11、ofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENOR

12、MALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.ENISO1735:2004:EEN ISO 1735:2004 (E) 2 Foreword This document (EN ISO 1735:2004) has been prepared by Technical C

13、ommittee ISO/TC 34 “Agricultural food products“ in collaboration with Technical Committee CEN/TC 302 “Milk and milk products - Methods 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

14、 an identical text or by endorsement, at the latest by January 2004, and conflicting national standards shall be withdrawn at the latest by January 2004. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this Eur

15、opean Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement

16、notice The text of ISO 1735:2004 has been approved by CEN as EN ISO 1735:2004 without any modifications. ENISO1735:2004 Reference numbers ISO 1735:2004(E) IDF 5:2004(E)INTERNATIONAL STANDARD ISO 1735 IDF 5 Third edition 2004-07-01 Cheese and processed cheese products Determination of fat content Gra

17、vimetric method (Reference method) Fromage et fromage fondu Dtermination de la teneur en matire grasse Mthode gravimtrique (Mthode de rfrence) ENISO1735:2004ii ENISO1735:2004IS:5371 O4002(E) IDF 5:2004(E) iiiContents Page Foreword iv Foreword. v 1 Scope 1 2 Normative references. 1 3 Terms and defini

18、tions. 1 4 Principle. 1 5 Reagents 1 6 Apparatus. 2 7 Sampling 3 8 Preparation of test sample. 3 9 Procedure. 4 9.1 Test portion. 4 9.2 Blank test. 4 9.3 Preparation of fat-collecting vessel 4 9.4 Determination 5 10 Calculation and expression of results 7 10.1 Calculation. 7 10.2 Expression of resul

19、ts 7 11 Precision 8 11.1 Interlaboratory test. 8 11.2 Repeatability 8 11.3 Reproducibility 8 12 Test report 8 Annex A (normative) Additional procedures . 9 Annex B (informative) Alternative procedure using fat-extraction tubes with siphon or wash-bottle fittings 11 Annex C (informative) Interlaborat

20、ory test. 14 Bibliography . 15 ENISO1735:2004IS:5371 O4002(E) IDF 5:2004(E) iv Foreword 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 out through I

21、SO 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 collaborates

22、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 Standards.

23、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 elements of this I

24、nternational Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 1735IDF 5 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (I

25、DF), in collaboration with AOAC International. It is being published jointly by ISO and IDF and separately by AOAC International. This edition of ISO 1735IDF 5 cancels and replaces ISO 1735:1987, which has been technically revised. ENISO1735:2004IS:5371 O4002(E) IDF 5:2004(E) vForeword IDF (the Inte

26、rnational Dairy Federation) is a worldwide federation of the dairy sector with a National Committee in every member country. Every National Committee has the right to be represented on the IDF Standing Committees carrying out the technical work. IDF collaborates with ISO and AOAC International in th

27、e development of standard methods of analysis and sampling for milk and milk products. Draft International 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 % o

28、f IDF National Committees casting a vote. International Standard ISO 1735IDF 5 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF), in collaboration with AOAC International. It is being published jointl

29、y by ISO and IDF and separately by AOAC International. All work was carried out by the Joint ISO/IDF/AOAC Action Team, Fat, of the Standing Committee, Main components in milk, under the aegis of its project leader, Mr G.J. Beutick (NL). This edition of ISO 1735IDF 5 cancels and replaces IDF 5B:1986,

30、 which has been technically revised. ENISO1735:2004blankNITERNATNOIAL STANDARD IS:5371 O4002(E) ID:5 F4002(E)1Cheese and processed cheese products Determination of fat content Gravimetric method (Reference method) WARNING The use of ISO 1735IDF 5 may involve hazardous materials, operations and equip

31、ment. This standard does not purport to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish safety and health practices and to determine the applicability of regulatory limitations prior to use. 1 Scope This International Standa

32、rd specifies the reference method for the determination of the fat content of all types of cheese and processed cheese products having lactose contents of below 5 % (mass fraction) of non-fat solids. 2 Normative references The following referenced documents are indispensable for the application of t

33、his document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3889:1977, Milk and milk products Determination of fat content Mojonnier-type fat extraction flasks 3 Terms and definition

34、s For the purposes of this document, the following terms and definitions apply. 3.1 fat content of cheese and processed cheese products mass fraction of substances determined by the procedure specified in this International Standard NOTE The fat content is expressed as a percentage by mass. 4 Princi

35、ple A test portion is digested with hydrochloric acid then ethanol is added. The acid-ethanolic solution is extracted with diethyl ether and light petroleum and the solvents are removed by distillation or evaporation. The mass of the substances extracted is determined. This is usually known as the S

36、chmid-Bondzynski-Ratzlaff principle. 5 Reagents Use only reagents of recognized analytical grade, unless otherwise specified, and 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 specif

37、ied (see 5.1). ENISO1735:2004IS:5371 O4002(E) IDF 5:2004(E) 2 5.1 Purity of reagents To test the quality of the reagents, carry out a blank test as specified in 9.2. Use an empty fat-collecting vessel, prepared as specified in 9.3, for mass control purposes. The reagents shall leave no residue great

38、er than 0,5 mg (see A.1 of Annex A). If the residue of the complete reagent blank test is greater than 0,5 mg, determine the residue of the solvents separately by distilling 100 ml of the diethyl ether and light petroleum, respectively. Use an empty control vessel to obtain the real mass of residue,

39、 which shall not exceed 0,5 mg. Replace unsatisfactory reagents or solvents, or redistil solvents. Very occasionally, the solvents may contain volatile matter which is strongly retained in fat. If there are indications of the presence of such substances, carry out blank tests on all the reagents and

40、 for each solvent using a fat-collecting vessel with about 1 g of anhydrous butterfat. If necessary, redistil solvents in the presence of 1 g of anhydrous butterfat per 100 ml of solvent. Use the solvents only shortly after the redistillation. 5.2 Concentrated hydrochloric acid, 20(HCl) = 1,18 g/ml.

41、 5.3 Dilute hydrochloric acid, 20(HCl) = 1,125 g/ml approximately. Dilute 675 ml of concentrated hydrochloric acid (5.2) to 1 000 ml with water and mix. 5.4 Ethanol, or ethanol denatured by methanol, containing at least 94 % (volume fraction) of ethanol (see A.5). 5.5 Diethyl ether, free from peroxi

42、des (see A.4), complying with the requirements for the blank test. 5.6 Light petroleum, with any boiling range between 30 C and 60 C or, as equivalent, pentane CH 3 (CH 2 ) 3 CH 3 , with a boiling point of 36 C. NOTE The use of pentane is recommended due to its higher purity and constant quality. 5.

43、7 Mixed solvent, prepared shortly before use by mixing equal volumes of diethyl ether (5.5) and light petroleum (5.6). 6 Apparatus WARNING Since the determination involves the use of volatile flammable solvents, electrical apparatus employed may be required to comply with legislation relating to the

44、 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 0,1 mg. 6.2 Centrifuge, capable of holding the fat-extraction flasks or tubes (6.6) and capable of spinning at a rotat

45、ional frequency of 500 min 1to 600 min 1to produce a radial acceleration of 80 g to 90 g at the outer end of the flasks or tubes. NOTE The use of the centrifuge is optional but recommended (see 9.4.7). 6.3 Distillation or evaporation apparatus, capable of distilling the solvents and ethanol from the

46、 flasks or capable of evaporating from beakers and dishes (9.4.13) at a temperature not exceeding 100 C. ENISO1735:2004IS:5371 O4002(E) IDF 5:2004(E) 36.4 Drying oven, electrically heated, with ventilation port(s) fully open, capable of being maintained at a temperature of 102 C 2 C throughout the w

47、orking space. The oven shall be fitted with a suitable thermometer. 6.5 Boiling water bath or hot plate. 6.6 Fat-extraction flasks, Mojonnier-type, as specified in ISO 3889. NOTE It is also possible to use fat-extraction tubes, with siphon or wash-bottle fittings, but the procedure is slightly diffe

48、rent then. The alternative procedure is specified in Annex B. The flasks shall be provided with good quality bark corks or stoppers of other material unaffected by the reagents used. Extract bark corks with the diethyl ether (5.5), then place in water at 60 C or more for at least 15 min. Then allow them to cool in the water so that they are saturated when used. 6.7 Rack, capable of holding the fat-extraction flasks (or tubes) (6.6). 6.8 Wash bottle, suitable for use with the mixed solvent (5.7