1、March 2009DEUTSCHE NORM English price group 12No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 67.100.10!$VZK“1515540ww
2、w.din.deDDIN EN ISO 1737Evaporated milk and sweetened condensed milk Determination of fat content Gravimetric method (Reference method) (ISO 1737:2008)English version of DIN EN ISO 1737:2009-03Kondensmilch und gezuckerte Kondensmilch Bestimmung des Fettgehaltes Gravimetrisches Verfahren (Referenzver
3、fahren) (ISO 1737:2008)Englische Fassung DIN EN ISO 1737:2009-03SupersedesDIN EN ISO 1737:2000-06www.beuth.deDocument comprises 22 pagesDIN EN ISO 1737:2009-03 2 National foreword This standard has been prepared by Technical Committee ISO/TC 34 “Food products” (Secretariat: AFNOR, France), Subcommit
4、tee SC 5 “Milk and milk products” (Secretariat: NEN, Netherlands) in collaboration with Technical Committee CEN/TC 302 “Milk and milk products Methods of sampling and analysis” (Secretariat: NEN, Netherlands). The responsible German body involved in its preparation was the Normenausschuss Lebensmitt
5、el und landwirtschaftliche Produkte (Food and Agricultural Products Standards Committee), Technical Committee Milch und Milchprodukte Probenahme- und Untersuchungsverfahren. Based on the results of parallel voting, ISO 1737:2008 has been adopted as a European Standard. For reasons of environmental a
6、nd worker protection, the German employers liability insurance associations and inspectorates forbid the open evaporation of diethyl ether, which this standard allows as an alternative method. One way of reducing risks is to substitute diethyl ether with an equivalent amount of tert-butyl methyl eth
7、er (t-BME). This deviation from the specified procedure is to be stated in the test report. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 707 DIN EN ISO 707 ISO 835 DIN EN ISO 835 ISO 1042 DIN EN ISO 1042 ISO 4788 DIN EN ISO 4788 Amen
8、dments This standard differs from DIN EN ISO 1737:2000-06 as follows: a) Clause 1 “Scope” has been rendered more precise. b) Clause 2 “Normative references” and clause 7 “Sampling” have been revised. c) The standard has been revised in form and substance and brought in line with the current rules of
9、 presentation. d) The bibliography has been updated. Previous editions DIN EN ISO 1737: 2000-06 DIN EN ISO 1737:2009-03 3 National Annex NA (informative) Bibliography DIN EN ISO 707, Milk and milk products Guidance on sampling DIN EN ISO 835, Laboratory glassware Graduated pipettes DIN EN ISO 1042,
10、Laboratory glassware One-mark volumetric flasks DIN EN ISO 4788, Laboratory glassware Graduated measuring cylinders DIN EN ISO 1737:2009-03 4 This page is intentionally blank EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 1737October 2008ICS 67.100.10 Supersedes EN ISO 1737:1999 English Versi
11、onEvaporated milk and sweetened condensed milk - Determinationof fat content - Gravimetric method (Reference method) (ISO 1737:2008)Lait concentr sucr et non sucr - Dtermination de lateneur en matire grasse - Mthode gravimtrique(Mthode de rfrence) (ISO 1737:2008)Kondensmilch und gezuckerte Kondensmi
12、lch -Bestimmung des Fettgehaltes - Gravimetrisches Verfahren(Referenzverfahren) (ISO 1737:2008)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 s
13、tatus of a national 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).
14、A version in 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,
15、 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 United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALIS
16、ATIONEUROPISCHES 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 1737:2008: EContents Page Foreword. 3 1 Scope 4 2 Normative references 4 3 Term and de
17、finitions .4 4 Principle4 5 Reagents.5 6 Apparatus .5 7 Sampling.6 8 Preparation of test sample7 8.1 Evaporated milk .7 8.2 Sweetened condensed milk7 9 Procedure .7 9.1 Test portion 7 9.2 Blank tests7 9.3 Preparation of fat-collecting vessel.8 9.4 Determination.8 10 Calculation and expression of res
18、ults.10 10.1 Calculation10 10.2 Expression of results 11 11 Precision.11 11.1 Interlaboratory test 11 11.2 Repeatability.11 11.3 Reproducibility.11 12 Test report 12 Annex A (informative) Notes on procedures 13 Annex B (informative) Alternative procedure using fat-extraction tubes with siphon or was
19、h-bottle fittings .15 Bibliography 18 EN ISO 1737:2008 (E) DIN EN ISO 1737:2009-03 2EN ISO 1737:2008 (E) Foreword This document (EN ISO 1737:2008) has been prepared by Technical Committee ISO/TC 34 “Agricultural food products“ in collaboration with Technical Committee CEN/TC 302 “Milk and milk produ
20、cts - 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 an identical text or by endorsement, at the latest by April 2009, and conflicting national standards shall be withdrawn a
21、t 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 and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 1737:1999. According to th
22、e CEN/CENELEC Internal Regulations, the national standards organizations of the following 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, Lithuan
23、ia, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 1737:2008 has been approved by CEN as a EN ISO 1737:2008 without any modification. DIN EN ISO 1737:2009-03 3WARNING The use
24、 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 International Standard to establish safety and health pract
25、ices and determine 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 all types of evaporated milk and sweetened condensed milk (liquid sweetened and unsweetened concentrated milk).
26、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, Laboratory glassw
27、are 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 Term and definitions For the purposes of this document, the fo
28、llowing terms and definitions apply. 3.1 fat content of evaporated milk and sweetened condensed milk mass fraction of substances determined by the procedure specified in this International Standard NOTE The fat content is expressed as a percentage mass fraction. 4 Principle An ammoniacal ethanolic s
29、olution 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 usually known as the Rse-Gottlieb principle. EN ISO 1737:2008 (E) DIN EN ISO 1737:2009-03 45 Reagen
30、ts 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 specified (see 9.2.2). 5.1 Ammonia solution, contai
31、ning a mass fraction of NH3ofapproximately 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 denatured by methanol, containing a volume fraction of ethanol
32、 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 solution, which allows the interface between the solvent and aqueous layers to be seen m
33、ore clearly, is optional (see 9.4.3). 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 mg/kg of antioxidants, and complying with the requireme
34、nts 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 30 C and 60 C or, as equivalent, pentane (CH3CH23CH3) wi
35、th 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 equal volumes of diethyl ether (5.4) and light petroleu
36、m (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, in particular, the following. 6.1 Analytical balance,
37、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 rotational frequency of 500 min1to 600 min1to produce a radial acceleration of 80g to 90g at the outer end of the flasks or
38、tubes. The use of the centrifuge is optional but recommended (see 9.4.6). 6.3 Distillation or evaporation apparatus, for distilling the solvents and ethanol from the boiling or conical flasks, or evaporating from beakers and dishes (see 9.4.13) at a temperature not exceeding 100 C. EN ISO 1737:2008
39、(E) DIN EN ISO 1737:2009-03 56.4 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 Water baths, capable of being maintained at a temp
40、erature of between 30 C and 40 C, and 40 C and 60 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 given in Annex B
41、. 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 more for a
42、t 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,
43、 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,
44、 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 capacity 10 ml, com
45、plying 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 the laboratory. I
46、t 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
47、 time of commencing the procedure. Store samples in sealed cans unopened at a temperature below 20 C. EN ISO 1737:2008 (E) DIN EN ISO 1737:2009-03 68 Preparation of test sample 8.1 Evaporated milk Shake and invert the sample container. Open the sample container and pour the sample slowly into a seco
48、nd sample container (provided with an airtight lid). Mix by repeated transfer, taking care to incorporate in the sample any fat or other constituent adhering to the wall and ends of the first container. Finally, transfer the product as completely as possible to the second container. If necessary in
49、the case of samples in sealed cans, condition the unopened container in the water bath (6.5) maintained at a temperature of between 40 C and 60 C. Remove and shake the can vigorously every 15 min. After 2 h, remove the can and allow it to cool to room temperature. Remove the lid entirely and thoroughly mix the sample by stirring with a spoon or spatula. (If fat separates, do not test the sample.) 8.2 Sweetened condensed milk Open the sample container and mix thoroughly with a spoon or spatula. Use an up-a
