1、BS EN ISO7328:2008ICS 67.100.40NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDMilk-based edibleices and ice mixes Determinationof fat content Gravimetric method(Reference method)(ISO 7328:2008)This British Standard was published under theauthority of the Standa
2、rdsPolicy and StrategyCommittee on 31 January2009 BSI 2009ISBN 978 0 580 63536 6Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 7328:2008National forewordThis British Standard is the UK implementation of EN ISO 7328:2008. Itsupersedes BS EN ISO 7328:2000 which is withdrawn.The U
3、K 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 publication does not purport to include all the necessary provisionsof a cont
4、ract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 7328October 2008ICS 67.100.40 Supersedes EN ISO 7328:1999 English VersionMilk-based edible ices and ice mixes
5、- Determination of fatcontent - Gravimetric method (Reference method) (ISO7328:2008)Glaces de consommation et prparations pour glaces base de lait - Dtermination de la teneur en matire grasse- Mthode gravimtrique (Mthode de rfrence) (ISO7328:2008)Speiseeis und Eis-Mischungen auf Milchbasis -Bestimmu
6、ng des Fettgehaltes - Gravimetrisches Verfahren(Referenzverfahren) (ISO 7328:2008)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 EuropeanStandard the status of a na
7、tional 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 (English, French, German). A version in
8、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, Bulgaria, Cyprus, Czech Republic, Denmark, Est
9、onia, 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 STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISC
10、HES 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 7328:2008: EBS EN ISO 7328:2008EN ISO 7328:2008 (E) 3 Foreword This document (EN ISO 7328:2008) has
11、 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. This European Standard shall be given the status of a national standa
12、rd, 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 elements of this document may be the subject of patent rights. CEN
13、and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 7328:1999. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Aus
14、tria, 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, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsem
15、ent notice The text of ISO 7328:2008 has been approved by CEN as a EN ISO 7328:2008 without any modification. BS EN ISO 7328:2008ISO 7328:2008(E) IDF 116:2008(E) ISO and IDF 2008 All rights reserved iiiContents Page Foreword iv Foreword. v 1 Scope 1 2 Normative references 1 3 Terms and definitions .
16、1 4 Principle2 5 Reagents.2 6 Apparatus .2 7 Sampling.4 8 Preparation of test sample4 8.1 Edible ices, ice mixes and concentrated ice mixes .4 8.2 Dried ice mixes.4 9 Procedure .4 9.1 Test portion 4 9.2 Blank tests5 9.3 Preparation of fat-collecting vessel.5 9.4 Determination.5 10 Calculation and ex
17、pression of results.8 10.1 Calculation8 10.2 Expression of results 8 11 Precision.8 11.1 Interlaboratory test 8 11.2 Repeatability.8 11.3 Reproducibility.9 12 Test report 9 Annex A (informative) Notes on procedures 10 Annex B (informative) Alternative procedure using fat-extraction tubes with siphon
18、 or wash-bottle fittings .12 Bibliography 15 BS EN ISO 7328:2008ISO 7328:2008(E) IDF 116:2008(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
19、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 committee. International organizations, governmental and non-governmental, in liaiso
20、n 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 with the rules given in the ISO/IEC Directives, Part 2. The main task of tec
21、hnical 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 approval by at least 75 % of the member bodies casting a vote. Attention is dra
22、wn 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 7328IDF 116 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk produc
23、ts, and the International Dairy Federation (IDF). It is being published jointly by ISO and IDF. This third edition of ISO 7328IDF 116 cancels and replaces the second edition (ISO 7328:1999), of which it constitutes a minor revision. BS EN ISO 7328:2008ISO 7328:2008(E) IDF 116:2008(E) ISO and IDF 200
24、8 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 having signed a formal agreement on cooperation w
25、ith 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 International Standards adopted by the Action Teams
26、 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 of the elements of this document may be the subjec
27、t of patent rights. IDF shall not be held responsible for identifying any or all such patent rights. ISO 7328IDF 116 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
28、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 7328IDF 116 cancels and replaces IDF 116:1987, of which it constitutes a minor revision. BS
29、 EN ISO 7328:2008BS EN ISO 7328:2008INTERNATIONAL STANDARD ISO 7328:2008(E)IDF 116:2008(E) ISO and IDF 2008 All rights reserved 1Milk-based edible ices and ice mixes Determination of fat content Gravimetric method (Reference method) WARNING The use of this International Standard may involve hazardou
30、s 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 the applicability of regulatory l
31、imitations prior to use. 1 Scope This International Standard specifies the reference method for the determination of the fat content of most milk-based edible ices and ice mixes. The method is also applicable to concentrated and dried ice mixes. The method is not applicable to some milk-based edible
32、 ices and ice mixes, in which the level of emulsifier, stabilizer or thickening agent or of egg yolk or of fruits, or of combinations of these constituents makes the Rse-Gottlieb method unsuitable. NOTE With such products, a method utilizing the Weibull-Berntrop principle (see ISO 8262-2IDF 124-23)
33、is suitable. 2 Normative 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, Labo
34、ratory 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 ISO 4788, Laboratory glassware Graduated measuring cylinders 3 Terms and definitions For the purposes of this do
35、cument, the following terms and definitions apply. 3.1 fat content of milk-based edible ices and ice mixes mass fraction of substances determined by the procedure specified in this International Standard NOTE The fat content is expressed as a percentage mass fraction. BS EN ISO 7328:2008ISO 7328:200
36、8(E) IDF 116:2008(E) 2 ISO and IDF 2008 All rights reserved4 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 is determined. NOTE This is usu
37、ally 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 determination is carried out by the met
38、hod specified (see 9.2.2). 5.1 Ammonia solution, containing a mass fraction of NH3of 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 9.4.2). 5.2 Ethanol (C2H5OH), or ethanol denatu
39、red 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 (6.16). Make up to the mark with water. NOTE The use of this solution, which allows the inter
40、face 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 Clause A.3), containing no more than 2
41、 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, with any boiling range between
42、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 Mixed solvent Shortly before use, mix
43、 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 solvents. Usual laboratory equipment and
44、, in particular, the following. 6.1 Analytical balance, capable of weighing to the nearest 1 mg, with a readability of 0,1 mg. BS EN ISO 7328:2008ISO 7328:2008(E) IDF 116:2008(E) ISO and IDF 2008 All rights reserved 36.2 Centrifuge, capable of holding the fat-extraction flasks or tubes (6.6) and cap
45、able of spinning at a 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 9.4.7). 6.3 Distillation or evaporation apparatus, for distilling the solvents and ethan
46、ol from the boiling or conical flasks, or evaporating 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
47、 shall be fitted with a suitable thermometer. 6.5 Water bath, capable of being maintained at a temperature of 65 C 2 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 p
48、rocedure 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) unaffected by the reagents used. Cork bungs shall be extracted with the dieth
49、yl ether (5.4), kept in water at a temperature of 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-collecting 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 di
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