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1、BS EN ISO 1736:2008 ICS 67.100.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Dried milk and dried milk products Determination of fat content Gravimetric method (Reference method)(ISO 1736:2008) Licensed Copy: London South Bank University, South Bank Unive
2、rsity, 02/02/2009 03:25, Uncontrolled Copy, (c) BSI This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 ber 2008 BSI 2008 ISBN 978 0 580 63533 5 Amendments/corrigenda issued since publication DateComments BS EN ISO 1736:2008 National foreword
3、This British Standard is the UK implementation of EN ISO 1736:2008. It supersedes BS EN ISO 1736:2000 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee AW/5, Chemical analysis of milk and milk products. A list of organizations represented on this commit
4、tee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Decem Licensed Copy: London S
5、outh Bank University, South Bank University, 02/02/2009 03:25, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 1736 October 2008 ICS 67.100.10Supersedes EN ISO 1736:2000 English Version Dried milk and dried milk products - Determination of fat content - Gravimetri
6、c method (Reference method) (ISO 1736:2008) Lait sec et produits base de lait sec - Dtermination de la teneur en matire grasse - Mthode gravimtrique (Mthode de rfrence) (ISO 1736:2008) Milchpulver und Trockenmilcherzeugnisse - Bestimmung des Fettgehaltes - Gravimetrisches Verfahren (Referenzverfahre
7、n) (ISO 1736:2008) 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 this European Standard the status of a national standard without any alteration. Up-to-date lists and
8、bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibi
9、lity of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland
10、, 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 EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de St
11、assart, 36 B-1050 Brussels 2008 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 1736:2008: E Licensed Copy: London South Bank University, South Bank University, 02/02/2009 03:25, Uncontrolled Copy, (c) BSI BS EN ISO 1736:2008 EN
12、 ISO 1736:2008 (E) 3 Foreword This document (EN ISO 1736:2008) has been prepared by Technical Committee ISO/TC 34 “Agricultural food products“ in collaboration with Technical Committee CEN/TC 302 “Milk and milk products - Methods of sampling and analysis” the secretariat of which is held by NEN. Thi
13、s 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 latest by April 2009. Attention is drawn to the possibility that some of the e
14、lements 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 1736:2000. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the foll
15、owing 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, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slo
16、venia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 1736:2008 has been approved by CEN as a EN ISO 1736:2008 without any modification. Licensed Copy: London South Bank University, South Bank University, 02/02/2009 03:25, Uncontrolled Copy, (c) BSI BS EN ISO 1
17、736:2008BS EN ISO 1736:2008 ISO 1736:2008(E) IDF 9:2008(E) ISO and IDF 2008 All rights 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 re
18、gional dairy associations 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 a
19、nd 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 % of the IDF National Committees casting a vote. Attention is drawn to t
20、he possibility that some 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 1736IDF 9 was prepared by the International Dairy Federation (IDF) and Technical Committee ISO/TC 34, Food products, Sub
21、committee SC 5, Milk and 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 1736IDF 9 cancels
22、and replaces IDF 9:1987, of which it constitutes a minor revision. Licensed Copy: London South Bank University, South Bank University, 02/02/2009 03:25, Uncontrolled Copy, (c) BSI BS EN ISO 1736:2008BS EN ISO 1736:2008 Licensed Copy: London South Bank University, South Bank University, 02/02/2009 03
23、:25, Uncontrolled Copy, (c) BSI BS EN ISO 1736:2008BS EN ISO 1736:2008 INTERNATIONAL STANDARD ISO 1736:2008(E) IDF 9:2008(E) ISO and IDF 2008 All rights reserved 1 Dried milk and dried milk products Determination of fat content Gravimetric method (Reference method) WARNING The use of this Internatio
24、nal 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 International Standard to establish safety and health practices and determine
25、the applicability of regulatory limitations prior to use. 1 Scope This International Standard specifies the reference method for the determination of the fat content of dried milk and dried milk products. The method is also applicable to dried milk with a fat content of 40 % mass fraction or more, d
26、ried whole, dried partially skimmed, and dried skimmed milk, dried whey, dried buttermilk and dried butter serum. The method is not applicable when the powder contains hard lumps which do not dissolve in ammonia solution or free fatty acids in significant quantities. NOTE When the powder contains ha
27、rd lumps which do not dissolve in ammonia solution or contains free fatty acids in significant quantities, noticeable by a distinct smell, the result of the determination will be too low. With such products, a method using the Weibull-Berntrop principle is suitable (see ISO 8262-3IDF 124-33). 2 Norm
28、ative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 835, Laboratory glassware Gr
29、aduated pipettes ISO 1042, Laboratory glassware One-mark volumetric flasks ISO 3889IDF 219, Milk and milk products Specification of Mojonnier-type fat extraction flasks ISO 4788, Laboratory glassware Graduated measuring cylinders 3 Terms and definitions For the purposes of this document, the followi
30、ng terms and definitions apply. 3.1 fat content of dried milk and dried milk products mass fraction of substances determined by the procedure specified in this International Standard NOTE The fat content is expressed as a percentage mass fraction. Licensed Copy: London South Bank University, South B
31、ank University, 02/02/2009 03:25, Uncontrolled Copy, (c) BSI BS EN ISO 1736:2008BS EN ISO 1736:2008 ISO 1736:2008(E) IDF 9:2008(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 a
32、re 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 specified, and only distilled or demineralized water or water of equi
33、valent 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 NH3 of approximately 25 % (20 = 910 g/l). NOTE If ammonia solution of this concentration is not available, a m
34、ore 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. Dissolve 1 g of Congo red (C32H22N6Na2O6S2) in water in a 100 ml one-m
35、ark 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 9.4.4). Other aqueous indicator solutions can be used provided that they do not affect the result of
36、 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 The use of diethyl ether can lead to hazardous situations. Observ
37、e 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 for the blank test (see 9.2.2, Clauses A.1 and A.4). The use of pen
38、tane 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 the use of volatile flammable solvents, all electrical apparatus em
39、ployed 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 0,1 mg. Licensed Copy: London South Bank University, South Bank Un
40、iversity, 02/02/2009 03:25, Uncontrolled Copy, (c) BSI BS EN ISO 1736:2008BS EN ISO 1736:2008 ISO 1736:2008(E) IDF 9:2008(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 min
41、1 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 evaporati
42、ng 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. 6.5 W
43、ater bath, capable of being maintained at a temperature of 65 C 5 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
44、given in Annex B. The fat-extraction flasks shall be provided with good quality cork bungs or stoppers of another 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
45、60 C or more 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-c
46、ollecting 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 Boili
47、ng 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 ml, complying with the requirements of ISO 4788, class A, or any other apparatus suitable for the product concerned. 6.12 Pipettes, graduated, of c
48、apacity 10 ml, complying with the requirements of ISO 835, class A. 6.13 Tongs, made of metal, for holding flasks, beakers or dishes. 6.14 Volumetric flask, one-mark, of capacity 100 ml, complying with the requirements of ISO 1042, class A. 7 Sampling A representative sample should have been sent to
49、 the laboratory. It should not have been damaged or changed during transport or storage. Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 707IDF 501. Store laboratory samples at a temperature between 2 C and 6 C from the time of sampling to the time of commencing the procedure. Licensed Copy: London South Bank University, South Bank University, 02/02/2009 03:25, Uncontrolled Copy, (c) BSI BS EN ISO 1736:2008BS EN ISO 1736:2008