1、BS ISO11865:2009ICS 67.100.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDInstant wholemilk powder Determination of whiteflecks numberThis British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2009 BS
2、I 2009ISBN 978 0 580 67127 2Amendments/corrigenda issued since publicationDate CommentsBS ISO 11865:2009National forewordThis British Standard is the UK implementation of ISO 11865:2009. Itsupersedes BS 1743-21:1996 which is withdrawn.The UK participation in its preparation was entrusted to Technica
3、lCommittee 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 contract. Users are responsible for its correct application. Com
4、pliance with a British Standard cannot confer immunityfrom legal obligations.BS ISO 11865:2009Reference numbersISO 11865:2009(E)IDF 174:2009(E)ISO and IDF 2009INTERNATIONAL STANDARD ISO11865IDF174Second edition2009-10-01Instant whole milk powder Determination of white flecks number Lait entier insta
5、ntan en poudre Dtermination du nombre de taches blanches BS ISO 11865:2009ISO 11865:2009(E) IDF 174:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which a
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10、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 copyrightiso.org E-mail infofil-idf.org Web www.iso.org Web www.fil-idf.org Published in Switzerland ii ISO and IDF 2009 All rights reservedBS ISO 11865:2009ISO 11865:2009
11、(E) IDF 174:2009(E) ISO and IDF 2009 All rights reserved iiiForeword 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 commit
12、tees. 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 liaison with ISO, also take part in the work. ISO collaborates closely with the In
13、ternational 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 technical committees is to prepare International Standards. Draft International
14、 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 drawn to the possibility that some of the elements of this document may be the
15、subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 11865IDF 174 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF). It is being published joi
16、ntly by ISO and IDF. This second edition of ISO 11865IDF 174 cancels and replaces the first edition (ISO 11865:1995), of which it constitutes a minor revision. BS ISO 11865:2009ISO 11865:2009(E) IDF 174:2009(E) iv ISO and IDF 2009 All rights reservedForeword IDF (the International Dairy Federation)
17、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. All members of IDF have the right to be represented on the IDF S
18、tanding 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. The main task of Standing Committees is to prepare International Standards. Draft International Standards adopted by the Action Te
19、ams 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 sub
20、ject of patent rights. IDF shall not be held responsible for identifying any or all such patent rights. ISO 11865IDF 174 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
21、 by IDF and ISO. All work was carried out by the former Joint ISO-IDF Group of Experts (E701 Physical properties of dried milk products) which is now part of the dormant Joint ISO-IDF Action Team on Physical properties and rheological tests of the Standing Committee on Minor components and character
22、ization of physical properties. This edition of ISO 11865IDF 174 cancels and replaces IDF 174:1993, of which it constitutes a minor revision. BS ISO 11865:2009INTERNATIONAL STANDARD ISO 11865:2009(E)IDF 174:2009(E) ISO and IDF 2009 All rights reserved 1Instant whole milk powder Determination of whit
23、e flecks number 1 Scope This International Standard specifies a method for the determination of the white flecks number (WFN) in instant whole milk powder. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 white flecks undissolved particles whi
24、ch are visible when reconstituted milk is observed in a thin layer 2.2 white flecks number WFN volume fraction of liquid which has not passed the sieve within 15 s when the procedure specified in this International Standard is followed 3 Principle Contrary to slowly dispersible particles, white flec
25、ks easily clog a filter or a fine mesh because they are numerous and soft. This property is used for their determination. The volume of liquid which remains on a defined sieve after a given time is therefore an expression of the amount of white flecks. 4 Apparatus Usual laboratory equipment and, in
26、particular, the following. 4.1 Analytical balance, capable of being read to the nearest 0,1 g. 4.2 Glass beaker, of capacity 400 ml, of inside diameter 70 mm and height 130 mm. 4.3 Spatula, of stainless steel, of thickness 1 mm and overall length 250 mm, with length and width of blade 135 mm and 25
27、mm, respectively. 4.4 Sieve, of diameter 100 mm, height about 45 mm and nominal size of openings 63 m (see ISO 3310-12)1). 1) A sieve produced by Siebtechnik is an example of a suitable product available commercially. This information is given for the convenience of users of this International Stand
28、ard and does not constitute an endorsement by ISO or IDF of this product. BS ISO 11865:2009ISO 11865:2009(E) IDF 174:2009(E) 2 ISO and IDF 2009 All rights reserved4.5 Glass funnel, of diameter 110 mm to 120 mm (see Figure 1). 4.6 Laboratory stand, with two rings, one for the sieve and one for the gl
29、ass funnel (see Figure 1). 4.7 Measuring cylinder, of capacity 250 ml, graduated in 2 ml intervals. 4.8 Stopwatch. Key 1 sieve, of diameter 100 mm and aperture size 63 m 2 supporting rings 3 glass funnel, of diameter 110 mm to 120 mm 4 measuring cylinder, 250 ml 5 laboratory stand Figure 1 Stand wit
30、h sieve and funnel (see Reference 5) BS ISO 11865:2009ISO 11865:2009(E) IDF 174:2009(E) ISO and IDF 2009 All rights reserved 35 Sampling Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 707|IDF 501. A representative sample sho
31、uld have been sent to the laboratory. It should not have been damaged or changed during transport or storage. 6 Preparation of test sample Mix the laboratory sample well and take test samples directly from it. 7 Procedure 7.1 If a check is required of whether the repeatability requirement (9.2) is m
32、et, carry out two single determinations in accordance with 7.2 to 7.8 under repeatability conditions. 7.2 Wet the sieve (4.4) and remove excess water using a filter paper. Fit the sieve and glass funnel (4.5) into the rings of the stand (4.6), placing the measuring cylinder (4.7) below the funnel so
33、 that the stem is positioned as shown in Figure 1. Adjust the sieve to a horizontal position. 7.3 Measure 100 ml 1 ml of water, at a temperature of 20 C 1 C, in a dry glass beaker (4.2). Add 24 g 0,1 g of test sample to the beaker, simultaneously starting the stopwatch (4.8). 7.4 When the stopwatch
34、indicates 5 s, insert the spatula down the side of the beaker until it touches the bottom. Over the next 5 s, stir the contents of the beaker with the spatula, making one complete stirring movement per second. Use a smooth continuous movement of the spatula across the beaker from one side to the oth
35、er and back for 1 s, keeping the end of the spatula blade in continuous contact with the bottom of the beaker. Slightly tilt the spatula away from the side of the beaker at the end of each half-stirring movement so as to minimize accumulation of unwetted test sample on the sides of the beaker. Witho
36、ut interruption, continue stirring for 15 s in the same manner, maintaining the spatula in a vertical position throughout. While making the 20 complete stirring movements in 20 s, continuously rotate the beaker on its base so that approximately one complete turn (360) is achieved during the stirring
37、. 7.5 After completion of the stirring, allow the contents of the beaker to stand for 30 s, i.e. until the stopwatch indicates 55 s, then add a further 100 ml 1 ml of water at 20 C 1 C. When the stopwatch indicates 60 s, repeat the stirring, making 20 complete stirring movements in 20 s while contin
38、uously rotating the beaker as described in 7.4. Stop the stopwatch. 7.6 Within about 5 s, pour off the liquid on the wetted sieve, and start the stopwatch again. 7.7 When the stopwatch shows 15 s, read the volume, V, of liquid in the measuring cylinder to the nearest 2 ml. 7.8 After each use, rinse
39、the sieve under running water and wash in warm water containing detergent. CAUTION It is important to keep the sieve clean. BS ISO 11865:2009ISO 11865:2009(E) IDF 174:2009(E) 4 ISO and IDF 2009 All rights reserved8 Calculation and expression of results 8.1 Calculation Calculate the WFN, nwf, using t
40、he formula: wf215215Vn= where 215 is the numerical value of the calculated volume, in millilitres, of the reconstituted liquid used as test sample; V is the numerical value of the volume of the filtrate, in millilitres, obtained in 15 s. 8.2 Expression of results Take as the result the arithmetic me
41、an of two results, if the repeatability requirement (9.2) is satisfied. Express the result to two decimal places. 9 Precision 9.1 General The values for repeatability limit and reproducibility limit have been derived from the results of an interlaboratory test carried out in accordance with ISO 5725
42、:19863. 9.2 Repeatability The absolute difference between two independent single test results, obtained using the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, shall not exceed 0,02. Reject both results if
43、 the difference exceeds 0,02 and carry out two new single determinations. 9.3 Reproducibility The absolute difference between two single test results, obtained using the same method on identical test material in different laboratories with different operators using different equipment, shall not exc
44、eed 0,07. 10 Test report The test report shall contain at least the following information: a) the sampling method used, if known; b) the test method used, including a reference to this International Standard; c) the test result(s) obtained; d) if the repeatability has been checked, the final quoted
45、result obtained; BS ISO 11865:2009ISO 11865:2009(E) IDF 174:2009(E) ISO and IDF 2009 All rights reserved 5e) all operating details not specified in this International Standard, or regarded as optional, together with details of any incidents that may have influenced the test result(s); f) all informa
46、tion required for the complete identification of the sample. BS ISO 11865:2009ISO 11865:2009(E) IDF 174:2009(E) 6 ISO and IDF 2009 All rights reservedBibliography 1 ISO 707IDF 50, Milk and milk products Guidance on sampling 2 ISO 3310-1, Test sieves Technical requirements and testing Part 1: Test si
47、eves of metal wire cloth 3 ISO 5725:19862), Precision of test methods Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests 4 LITMAN, I.I., ASHWORTH, U.S. Insoluble scum-like materials on reconstituted whole milk powders. J. Dairy Sci. 1957, 40, pp.
48、403-409 5 GEA NIRO. Analytical methods for dry milk products, 4th edition. GEA Niro, Copenhagen, 1978. Available (2009-03-23) at: http:/ 2) Superseded. BS ISO 11865:2009BS ISO 11865:2009ISO 11865:2009(E) IDF 174:2009(E) ICS 67.100.10 Price based on 6 pages ISO and IDF 2009 All rights reserved BS ISO
49、 11865:2009This page has been intentionally left blankBS ISO11865:2009BSI GroupHeadquarters 389Chiswick High Road,London, W4 4AL, UKTel +44 (0)20 8996 9001Fax +44 (0)20 8996 - British Standards InstitutionBSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at theinternational level. It is incorporated by Royal Charter.R
