BS PD ISO TS 17758-2014 Instant dried milk Determination of the dispersibility and wettability《速溶奶粉 分散性和润湿性的测定》.pdf

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1、BSI Standards Publication PD ISO/TS 17758:2014 Instant dried milk Determination of the dispersibility and wettabilityPD ISO/TS 17758:2014 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of ISO/TS 17758:2014. The UK participation in its preparation was entrusted

2、to Technical Committee AW/5, Chemical analysis of milk and milk products. A list of organizations represented on this committee 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

3、application. The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 77888 9 ICS 67.100.10 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy and St

4、rategy Committee on 30 June 2014. Amendments/corrigenda issued since publication Date T e x t a f f e c t e dPD ISO/TS 17758:2014 Instant dried milk Determination of the dispersibility and wettability Poudre de lait instantane Dtermination de la dispersibilit et de la mouillabilit First edition 2014

5、-06-15 ISO and IDF 2014 ISO/TS 17758 TECHNICAL SPECIFICATION IDF/RM 87 Reference numbers ISO/TS 17758:2014(E) IDF/RM 87:2014(E)PD ISO/TS 17758:2014ISO/TS 17758:2014(E) IDF/RM 87:2014(E) ii ISO and IDF 2014 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO/IDF 2014 All rights reserved. Unless othe

6、rwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO or IDF at the r

7、espective address below or ISOs member body in the country of the requester. ISO copyright office International Dairy Federation Case postale 56 CH-1211 Geneva 20 Silver Building Bd Auguste Reyers 70/B B-1030 Brussels Tel. + 41 22 749 01 11 Tel. + 32 2 325 67 40 Fax + 41 22 749 09 47 Fax + 32 2 325

8、67 41 E-mail copyrightiso.org E-mail infofil-idf.org Web www.iso.org Web www.fil-idf.org Published in SwitzerlandPD ISO/TS 17758:2014ISO/TS 17758:2014(E) IDF/RM 87:2014(E) ISO and IDF 2014 All rights reserved iii Contents Page Forewords .iv Introduction vi 1 Scope . 1 2 Normative references 1 3 Prin

9、ciple 1 4 Reagents 1 5 Apparatus . 1 6 Sampling 2 7 Preparation of test sample . 2 8 Procedure. 3 8.1 Pretreatment of test sample 3 8.2 Moisture content of pretreated test sample 3 8.3 Test method . 3 9 Expression of results 5 9.1 Method of calculation 5 9.2 Repeatability . 5 10 Test report . 6 Anne

10、x A (informative) Recommendation for interpretation of dispersibility values .7 Annex B (informative) Determination of the wettability (wetting time) of instant dried milk 8 Bibliography .10PD ISO/TS 17758:2014ISO/TS 17758:2014(E) Forewords ISO (the International Organization for Standardization) is

11、 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 interested in a subject for which a technical committee has been established has the right to be represen

12、ted 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 Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop

13、 this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IE

14、C Directives, Part 2 (see www.iso.org/directives). Attention is drawn 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. Details of any patent rights identified during the

15、 development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning

16、of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 34, Foo

17、d and food products, Subcommittee SC 5, Milk and milk products and the International Dairy Federation (IDF). It is being published jointly by ISO and IDF. IDF/RM 87:2014(E) iv ISO and IDF 2014 All rights reservedPD ISO/TS 17758:2014ISO/TS 17758:2014(E) IDF (the International Dairy Federation) is a n

18、on-profit private sector organization representing the interests of various stakeholders in dairying at the global level. IDF members are organized in National Committees, which are national associations composed of representatives of dairy-related national interest groups including dairy farmers, d

19、airy processing industry, dairy suppliers, academics and governments/food control authorities. ISO and IDF collaborate closely on all matters of standardization relating to methods of analysis and sampling for milk and milk products. Since 2001, ISO and IDF jointly publish their International Standa

20、rds using the logos and reference numbers of both organizations. Attention is drawn to the 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. Details of any patent rights identif

21、ied during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). This document was prepared by the IDF Standing Committee on Analytical Methods for Composition and ISO Technical Committee ISO/TC 34, Food and food

22、 products, Subcommittee SC 5, Milk and milk products. This IDF Reviewed method is equal to an ISO Publicly Available Specification (ISO/PAS) or an ISO Technical Specification (ISO/TS) and is therefore published jointly under ISO conditions. The work was carried out by the IDF/ISO Project Group C28 o

23、f the Standing Committee on Analytical Methods for Composition under the aegis of its project leader, Dr. Steve Holroyd (NZ). This ISO Technical Specification/IDF Reviewed Method replaces the standard IDF 87:1979, Instant dried milk Determination of the dispersibility and wettability which has been

24、withdrawn. IDF/RM 87:2014(E) ISO and IDF 2014 All rights reserved vPD ISO/TS 17758:2014ISO/TS 17758:2014(E) Introduction The degree to which a dried milk is “instant” depends on various properties which can be classified as wettability, sinkability, dispersibility, and solubility. The first three af

25、fects the last to some extent and, hence, dispersibility, as defined and determined in this Technical Specification, is probably the best single criterion for assessing the overall instant characteristics of a dried milk. Provisional recommendations for acceptable dispersibility values for instant d

26、ried skimmed milk and instant dried whole milk are given in Annex A. Although wettability is a property not easily distinguishable from sinkability and is difficult to measure accurately, in milk powders, an approximate determination of wettability, which can be made rapidly, provides a useful indic

27、ation of the degree to which a dried milk is likely to possess instant characteristics. In Annex B, a rapid routine method for the determination of the wettability (wetting time) in water of instant dried milk is described. IDF/RM 87:2014(E) vi ISO and IDF 2014 All rights reservedPD ISO/TS 17758:201

28、4TECHNICAL SPECIFICATION ISO/TS 17758:2014(E) IDF/RM 87:2014(E) Instant dried milk Determination of the dispersibility and wettability 1 Scope This Technical Specification specifies a method for the determination of the dispersibility in water of instant dried milk. The method is applicable to insta

29、nt dried skimmed milk manufactured by either the “straight-through” or the “re-wet” process and also to instant dried whole milk. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated refe

30、rences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5537|IDF 26, Dried milk Determination of moisture content (Reference method) ISO 6731|IDF 21, Milk, cream and evaporated milk Determination of total s

31、olids content (Reference method) 3 Principle A test portion of the sample of known moisture content is evenly spread on the surface of water at a temperature of 25 C. The mixture is stirred manually for a short time; then, part of the mixture is filtered through a sieve, and the total solids content

32、 of the collected liquid determined. Dispersibility is calculated from the mass of the test portion and the values for moisture content and total solids content. 4 Reagents Use only distilled or demineralized water or water of equivalent purity. 5 Apparatus 5.1 Container, capacity about twice the vo

33、lume of the laboratory sample (Clause 6), with airtight lid. 5.2 Apparatus, as specified in ISO 5537|IDF 26. 5.3 Balance, top-pan, capable of being read to the nearest 0,1 g. 5.4 Scoop, suitable for transporting the test portion (8.3.2) for weighing. 5.5 Thermometer, suitable for measuring a tempera

34、ture of (25 1) C. 5.6 Glass beaker, with spout, capacity 600 ml, external diameter (90 2) mm, overall height (126 3) mm, graduated at 150 ml and 250 ml, with the rim lying in a horizontal plane parallel to the base see Figure 1 a). 5.7 Glass plate, 120 mm 120 mm, thickness 2,5 mm, with ground edges

35、see Figure 1 a). ISO and IDF 2014 All rights reserved 1PD ISO/TS 17758:2014ISO/TS 17758:2014(E) 5.8 Glass tubing, length 65 mm, outside diameter (80 1,8) mm, wall thickness (2,5 0,3) mm, with the ends ground, parallel, and at right angles to the longitudinal axis see Figure 1 a). 5.9 Stand and clamp

36、, for holding the glass tubing (5.8). 5.10 Brush, suitable for removing the test portion from the scoop (5.4). 5.11 Spatula, stainless steel, thickness 1 mm, overall length 250 mm, length of blade 135 mm, width of blade 25 mm see Figure 1 b). These dimensions should be adhered to as closely as possi

37、ble. 5.12 Stopwatch, 60 s, numbered at intervals of 5 s, indicating intervals of 1 s and 0,5 s (or less). It is helpful to have the dial marked at 5 s, 25 s, and 55 s. 5.13 Test sieve, diameter 200 mm, woven metal wire cloth, nominal size of apertures 150 m, with receiver, complying with ISO 565 1 .

38、 5.14 Conical flask, capacity 250 ml, with stopper. 5.15 Glass funnel, suitable for transferring the contents of the sieve receiver to the conical flask (see 8.3.9). 5.16 Apparatus, as specified in ISO 6731|IDF 21. 6 Sampling Sampling is not part of the method specified in this Technical Specificati

39、on. A recommended sampling method is given in ISO 707|IDF 50 2 . It is important that the laboratory receives a representative sample which has not been damaged or changed during transport or storage. The laboratory sample shall be placed in a clean, dry, securely closed, airtight container. With in

40、stant dried milk, it is essential that care is taken during sampling to avoid reducing the particle size of the dried milk and to prevent this happening during transport of the laboratory sample, the sample container should be completely filled. Note and report any deviation from these requirements.

41、 7 Preparation of test sample Transfer all the laboratory sample, which should be at ambient temperature, to the container (5.1) and immediately close the container. Thoroughly mix the sample by very gently inverting and rotating the container in such a way as to avoid reducing the particle size of

42、the sample. IDF/RM 87:2014(E) 2 ISO and IDF 2014 All rights reservedPD ISO/TS 17758:2014ISO/TS 17758:2014(E) 1 2 3 4 5 Key 1 glass tubing (5.8) 4 spatula (5.11) handle 2 glass plate (5.7) 5 spatula (5.11) blade 3 glass beaker (5.6) Figure 1 Apparatus for the determination of dispersibility and wetti

43、ng time (diagrammatic) 8 Procedure 8.1 Pretreatment of test sample Before proceeding with the operations specified in 8.2 and 8.3, ensure that the test sample (Clause 7) has been at laboratory temperature (20 C to 25 C) for at least 48 h. This pretreatment is necessary with all test samples so that

44、any influence on dispersibility attributable to the physical state of the fat is constant from sample to sample. 8.2 Moisture content of pretreated test sample Carry out, in duplicate, the procedure specified in ISO 5537|IDF 26 to obtain two single values (to the nearest 0,01 % mass fraction) for th

45、e moisture content of the pretreated test sample (8.1). Record the mean of these values, to the nearest 0,1 % mass fraction, as the moisture content. 8.3 Test method 8.3.1 Carry out the test method in duplicate to obtain duplicate single values for dispersibility. 8.3.2 Mix the pretreated test sampl

46、e (8.1) by very gently inverting and rotating the container a few times. Using the balance (5.3), weigh out in the scoop (5.4) (26 0,1) g of instant dried skimmed milk or (34 0,1) g of instant dried whole milk. 8.3.3 Weigh out (250 0,1) g of water, adjusted to (25 1) C, in a dry glass beaker (5.6),

47、taking care that the inside of the beaker above the final water level remains dry. NOTE Recommended water temperature is 25 C. In laboratories, for skimmed milk powder, water temperature used is 25 C and for whole milk powder, water temperature is 40 C. IDF/RM 87:2014(E) ISO and IDF 2014 All rights

48、reserved 3PD ISO/TS 17758:2014ISO/TS 17758:2014(E) 8.3.4 Place the beaker strictly horizontally on the base of the stand (5.9), place the glass plate (5.7) centrally on the top of the beaker, and place the glass tubing (5.8) on the glass plate, clamping the tubing so that it is centrally located abo

49、ve the beaker and the glass plate is free enough to be withdrawn see Figure 1 a). 8.3.5 Transfer all of the test portion (8.3.2) into the glass tubing, using the brush (5.10) if necessary, and spread the test portion evenly over the glass plate with the spatula (5.11). 8.3.6 Start the stopwatch (5.12) and, when after 1 min its main hand again indicates 0/60 s, withdraw the glass plate with one hand (holding the beaker with the other hand) so that the test portion progressively falls o