ISO-1854-1999.pdf
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1、A Reference number ISO 1854:1999(E) INTERNATIONAL STANDARD ISO 1854 Third edition 1999-10-01 Whey cheese Determination of fat content Gravimetric method (Reference method) Fromage de srum Dtermination de la teneur en matire grasse Mthode gravimtrique (Mthode de rfrence) Copyright International Organ
2、ization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 22:23:55 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 1854:1999(E) ISO 1999 All rights reserved. Unless otherwise specified, n
3、o 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 writing from the publisher. International Organization for Standardization Case postale 56 CH-1211 Genve 20 Switzerland Internet
4、isoiso.ch Printed in Switzerland ii Contents 1 Scope1 2 Normative reference1 3 Term and definition .1 4 Principle1 5 Reagents.2 6 Apparatus.2 7 Sampling.3 8 Preparation of test sample3 9 Procedure.4 9.1 Test portion.4 9.2 Blank tests.4 9.3 Preparation of fat-collecting vessel4 9.4 Determination5 10
5、Calculation and expression of results.7 10.1 Calculation.7 10.2 Expression of results .7 11 Precision.7 11.1 Interlaboratory test.7 11.2 Repeatability7 11.3 Reproducibility8 12 Test report8 Annex A (informative) Notes on procedures9 Annex B (informative) Alternative procedure using fat-extraction tu
6、bes with siphon or wash-bottle fittings 11 Bibliography14 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 22:23:55 MDTNo reproduction or networking permitted without license from
7、 IHS -,-,- ISOISO 1854:1999(E) iii 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 ISO technical committees. Each member body in
8、terested 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 closely with the International Electrotechni
9、cal Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publica
10、tion as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 1854 was prepared by Technical Committee ISO/TC 34, Agricultural food products, Subcommittee SC 5, Milk and milk products, in collaboration with the International Dair
11、y Federation (IDF) and AOAC International, and will also be published by these organizations. This third edition cancels and replaces the second edition (ISO 1854:1987), which has been technically revised. Annexes A and B of this International Standard are for information only. Copyright Internation
12、al Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 22:23:55 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright International Organization for Standardization Provided by
13、 IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 22:23:55 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISOISO 1854:1999(E) 1 Whey cheese Determination of fat content Gravimetric method (Reference
14、 method) WARNING: The use of this International Standard may involve hazardous materials, operations and equipment. 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 practice
15、s 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. NOTE If the whey cheese does not dissolve completely in the ammonia or if it contains free fatty acids in
16、significant quantities (only in exceptional cases and then noticeable by a distinct smell), the result of the determination will be too low. With such products recourse should be made to a method utilizing the Weibull-Berntrop principle (see ISO 8262-3). 2 Normative reference The following normative
17、 document contains provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, this publications do not apply. However, parties to agreement based on this International Standard are encourage
18、d to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 3889, Mi
19、lk and milk products Determination of fat content Mojonnier-type fat extraction flasks. 3 Term and definition For the purposes of this International Standard, the following term and definition apply. 3.1 fat content of whey cheese mass fraction of substances determined by the procedure specified in
20、this International Standard. NOTE The fat content is expressed as a mass fraction, in percent formerly given as % (m/m). 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 ma
21、ss of the substances extracted is determined. NOTE This is usually known as the Rse-Gottlieb principle. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 22:23:55 MDTNo reproductio
22、n or networking permitted without license from IHS -,-,- ISO 1854:1999(E) ISO 2 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 determ
23、ination 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
24、Ethanol (C2H5OH), or ethanol denatured by methanol, containing a volume fraction of ethanol of at least 94 %. (See A.5.) 5.3 Congo red solution Dissolve 1 g of Congo red in water in a 100 ml one-mark volumetric flask (6.14). Dilute to the mark with water. NOTE The use of this solution, which allows
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