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1、 Reference numbers ISO 1854:2008(E) IDF 59:2008(E) ISO and IDF 2008 INTERNATIONAL STANDARD ISO 1854 IDF 59 Fourth edition 2008-10-15 Whey cheese Determination of fat content Gravimetric method (Reference method) Fromage de srum Dtermination de la teneur en matire grasse Mthode gravimtrique (Mthode d
2、e rfrence) Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/29/2009 22:44:21 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 1854:2008(E) IDF 59:2008(E) PDF disclaimer This P
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6、 the address given below. COPYRIGHT PROTECTED DOCUMENT ISO and IDF 2008 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writin
7、g from either ISO or IDF at the respective address below. ISO copyright office International Dairy Federation Case postale 56 CH-1211 Geneva 20 Diamant Building Boulevard Auguste Reyers 80 B-1030 Brussels Tel. + 41 22 749 01 11 Tel. + 32 2 733 98 88 Fax + 41 22 749 09 47 Fax + 32 2 733 04 13 E-mail
8、copyrightiso.org E-mail infofil-idf.org Web www.iso.org Web www.fil-idf.org Published in Switzerland ii ISO and IDF 2008 All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/29/2009 22:44:
9、21 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 1854:2008(E) IDF 59:2008(E) ISO and IDF 2008 All rights reserved iii Contents Page Foreword iv Foreword. v 1 Scope 1 2 Normative reference1 3 Terms and definitions .1 4 Principle2 5 Reagents.2 6 Apparatus .2 7 Sampling.
10、3 8 Preparation of test sample4 9 Procedure .4 9.1 Test portion4 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 test8 11.2 Repeatability.8 11
11、.3 Reproducibility.8 12 Test report8 Annex A (informative) Notes on procedures9 Annex B (informative) Alternative procedure using fat-extraction tubes with siphon or wash-bottle fittings.11 Bibliography14 Copyright International Organization for Standardization Provided by IHS under license with ISO
12、 Licensee=Boeing Co/5910770001 Not for Resale, 01/29/2009 22:44:21 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 1854:2008(E) IDF 59:2008(E) iv ISO and IDF 2008 All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federa
13、tion 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 right to be represented on that committ
14、ee. 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. International Standards are drafted in accordance
15、 with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires ap
16、proval by at least 75 % of the member bodies casting a vote. 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. ISO 1854IDF 59 was prepared by Technical
17、 Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF). It is being published jointly by ISO and IDF. This fourth edition of ISO 1854IDF 59 cancels and replaces the third edition (ISO 1854:1999), of which it constitutes a minor re
18、vision. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/29/2009 22:44:21 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 1854:2008(E) IDF 59:2008(E) ISO and IDF 2008 All rig
19、hts reserved v Foreword 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 having signed a formal agreement on cooperation with IDF.
20、 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 International Standards adopted by the Action Teams and Sta
21、nding 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 of the elements of this document may be the subject of pat
22、ent rights. IDF shall not be held responsible for identifying any or all such patent rights. ISO 1854IDF 59 was prepared by the International Dairy Federation (IDF) and Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is being published jointly by IDF and I
23、SO. 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 1854IDF 59 cancels and replaces IDF 59:1986, of which it constitutes a minor revision. Copyright Int
24、ernational Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/29/2009 22:44:21 MSTNo reproduction or networking permitted without license from IHS -,-,- Copyright International Organization for Standardization Provided by IHS unde
25、r license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/29/2009 22:44:21 MSTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISO 1854:2008(E) IDF 59:2008(E) ISO and IDF 2008 All rights reserved 1 Whey cheese Determination of fat content Gravim
26、etric method (Reference method) WARNING The use of this International Standard may involve hazardous materials, operations and equipment. This International Standard does not purport to address all the safety problems associated with its use. It is the responsibility of the user of this Internationa
27、l 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 method for the determination of fat content of whey cheese. The method is not applicable to products which do not di
28、ssolve completely in ammonia solution or which contain free fatty acids in significant quantities. NOTE If the whey cheese does not dissolve completely in the ammonia or if it contains free fatty acids in significant quantities (only in exceptional cases and then noticeable by a distinct smell), the
29、 result of the determination will be too low. With such products, a method using 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 edi
30、tion cited applies. For undated 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-
31、type fat extraction flasks 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 whey cheese mass fraction of substances determined by the procedure specified in this Inter
32、national Standard NOTE The fat content is expressed as a percentage mass fraction. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/29/2009 22:44:21 MSTNo reproduction or networking permitted without lice
33、nse from IHS -,-,- ISO 1854:2008(E) IDF 59:2008(E) 2 ISO and IDF 2008 All rights reserved 4 Principle An ammoniacal ethanolic solution of a test portion is extracted with diethyl ether and light petroleum. The solvents are removed by distillation or evaporation. The mass of the substances extracted
34、is determined. NOTE This is usually known as the Rse-Gottlieb principle. 5 Reagents Use only reagents of recognized analytical grade, unless otherwise specified, and only distilled or demineralized water or water of equivalent purity. The reagents shall leave no appreciable residue when the determin
35、ation is carried out by the method specified (see 9.2.2). 5.1 Ammonia solution, containing a mass fraction of NH3 of approximately 25 % (20 = 910 g/l). NOTE If ammonia solution of this concentration is not available, a more concentrated solution of known concentration may be used (see 9.4.3). 5.2 Et
36、hanol (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 Dissolve 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
37、 solution, which allows the interface between the solvent and aqueous layers to be seen more clearly, is optional (see 9.4.4). Other aqueous indicator solutions can be used provided that they do not affect the result of the determination. 5.4 Diethyl ether (C2H5OC2H5), free from peroxides (see Claus
38、e 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 The use of diethyl ether can lead to hazardous situations. Observe current safety precautions for handling, use, and disposal. 5.5 Light petroleum
39、, 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 for 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 Mixe
40、d solvent Shortly before use, mix equal volumes of diethyl ether (5.4) and light petroleum (5.5). 6 Apparatus WARNING Since the determination involves the use of volatile flammable solvents, all electrical apparatus employed shall comply with legislation relating to the hazards in using such solvent
41、s. 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. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale
42、, 01/29/2009 22:44:21 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 1854:2008(E) IDF 59:2008(E) ISO and IDF 2008 All rights reserved 3 6.2 Centrifuge, capable of holding the fat-extraction flasks or tubes (6.6) and capable of spinning at a rotational frequency of 500
43、min1 to 600 min1 to 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 9.4.7). 6.3 Distillation or evaporation apparatus, for distilling the solvents and ethanol from the boiling or conical flasks, or evapor
44、ating from beakers and dishes (see 9.4.14) 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 a suitable thermometer. 6.
45、5 Water bath, capable of maintaining water at boiling point. 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 i
46、n 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) unaffected by the reagents used. Cork bungs shall be extracted with the diethyl ether (5.4), kept in water at a temperature of 60 C or m
47、ore for at least 15 min, and shall then be allowed to cool in the water so that they are saturated when used. 6.7 Rack, for holding the fat-extraction flasks (or tubes) (6.6). 6.8 Wash bottle, suitable for use with the mixed solvent (5.6). A plastics wash bottle shall not be used. 6.9 Fat-collecting
48、 vessels, such as boiling flasks (flat-bottomed), of capacities 125 ml to 250 ml, conical flasks, of capacity 250 ml, or metal dishes. If metal dishes are used, they shall be of stainless steel, flat-bottomed with a diameter of 80 mm to 100 mm and a height of approximately 50 mm. 6.10 Boiling aids, fat-free, of non-porous porcelain or silicon carbide (optional when metal dishes are used). 6.11 Measuring cylinders, of capacities 5 ml and 25