1、BRITISH STANDARD BS ISO 5739:2003 Caseins and caseinates Determination of contents of scorched particles and of extraneous matter ICS 67.100.99 BS ISO 5739:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 27 January 2003 BSI 27 January 20
2、03 ISBN 0 580 41143 5 National foreword This British Standard reproduces verbatim ISO 5739:2003 and implements it as the UK national standard. It supersedes BS 6248-9:1984 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee AW/5, Milk and milk products, w
3、hich has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitl
4、ed “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance
5、with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related inter
6、national and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to vi, pages 1 to 12, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when
7、the document was last issued. Amendments issued since publication Amd. No. Date Comments RECIPIENTS OF THIS DOCUMENT ARE INVITED TO SUBMIT, WITH THEIR COMMENTS, NOTIFI- CATION OF ANY RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE AND TO PROVIDE SUPPORTING DOCUMENTATION. IN ADDITION TO THEIR EVALUATI
8、ON AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO- LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STAN- DARDS TO WHICH REFERENCE MAY BE MADE IN NATIONAL REGULATIONS. Reference numbers ISO 5739:2003(E) I
9、DF 107:2003(E)INTERNATIONAL STANDARD ISO 5739 IDF 107 Second edition 2003-01-15 Caseins and caseinates Determination of contents of scorched particles and of extraneous matter Casines et casinates Dtermination de la teneur en particules brles et en matires exognes BSISO5739:2003DPlcsid Fremia ihTs P
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13、 teh serddas igleb nevow. ii BSISO5739:2003 iiiContents Page Foreword ISO. iv Foreword IDF v Introduction . vi 1 Scope 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle . 1 5 Reagents 1 6 Apparatus 2 7 Sampling 3 8 Procedure 3 8.1 Preparation of test sample. 3 8.2 Test portion . 4
14、8.3 Determination 4 9 Evaluation and expression of results . 5 9.1 Evaluation 5 9.2 Expression of results 5 10 Precision 5 10.1 Repeatability 5 10.2 Reproducibility 5 11 Test report . 6 Annex A (normative) Testing of filtering discs 7 Annex B (normative) Preparation of standard discs of scorched par
15、ticles. 10 Bibliography . 12 BSISO5739:2003iv Foreword 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 committees. Each mem
16、ber 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 International El
17、ectrotechnical 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 Standards ado
18、pted 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 subject of pat
19、ent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 5739IDF 107 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF), in collaboration with AOAC International
20、. It is being published jointly by ISO and IDF and separately by AOAC International. This edition of ISO 5739IDF 107 cancels and replaces the first edition of ISO 5739:1983, which has been technically revised. BSISO5739:2003 vForeword IDF (the International Dairy Federation) is a worldwide federatio
21、n of the dairy sector with a National Committee in every member country. Every National Committee has the right to be represented on the IDF Standing Committees carrying out the technical work. IDF collaborates with ISO and AOAC International in the development of standard methods of analysis and sa
22、mpling for milk and 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 National Committees casting a vote. ISO 5739ID
23、F 107 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF), in collaboration with AOAC International. It is being published jointly by ISO and IDF and separately by AOAC International. All work was carri
24、ed out by the Joint ISO/IDF/AOAC Action Team, Physical properties of dried milk products, of the Standing Committee on Minor components and characterization of physical properties, under the aegis of its project leader, Mr. J. de Vilder (BE). This edition of ISO 5739IDF 107 cancels and replaces the
25、first edition of IDF 107A:1995, which has been technically revised. BSISO5739:2003vi Introduction The method is derived from procedures developed by the United States Department of Agriculture (USDA) for the determination of scorched particles in dried milk. BSISO5739:2003NITERNATNOIAL STANDARD IS:9
26、375 O3002(E) ID:701 F002(3)E1Caseins and caseinates Determination of contents of scorched particles and of extraneous matter 1 Scope This International Standard specifies a method for the determination of the contents of scorched particles and of extraneous matter in caseins and caseinates. 2 Normat
27、ive 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 3310-1, Test sieves Technical
28、requirements and testing Part 1: Test sieves of metal wire cloth 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 scorched particles content of caseins and caseinates amount of coloured residue per 25 g of test sample, determined and classifie
29、d by the procedure specified in this International Standard NOTE The scorched particles content is expressed by classification. 3.2 extraneous matter any foreign matter in the product associated with objectionable conditions or practices in production, storage or distribution 4 Principle A test port
30、ion is dissolved in a hot solution of sodium carbonate, sodium polyphosphate or disodium ethylenediaminetetraacetate, or in sodium hydroxide solution at room temperature or at 60 C 1 C. The solution obtained is filtrated through a filtering disc and dried. The dried disc with the scorched particles
31、is visually compared with standard discs. 5 Reagents Use only reagents of recognized analytical grade, unless otherwise specified, and distilled or demineralized water or water of equivalent purity. BSISO5739:20032 5.1 Sodium carbonate solution (Na 2 CO 3 ), for acid caseins and for caseinates. Diss
32、olve 100 g of anhydrous sodium carbonate in water in a 1 000 ml conical flask (6.2). Dilute to 1 000 ml with water and mix thoroughly until completely dissolved. Use the filtering device (6.6) and the filtering disc (6.5) to filter the solution into another 1 000 ml conical flask. 5.2 Sodium polypho
33、sphate solution (Na 5 P 3 O 10 ), for rennet caseins. Dissolve 20 g of a sodium polyphosphate (tripolyphosphate or a higher polyphosphate as used in the manufacture of processed cheese) in water in a conical flask (6.2). Dilute to 1 000 ml with water and mix thoroughly until complete dissolution. Us
34、e the filtering device (6.6) and the filtering disc (6.5) to filter the solution into another 1 000 ml conical flask. 5.3 Disodium ethylenediaminetetraacetate solution (C 10 H 14 N 2 Na 2 O 8 ), for calcium caseinates. Dissolve 100 g of disodium ethylenediaminetetraacetate (EDTA) dihydrate in water
35、in a 1 000 ml conical flask (6.2). Dilute to 1 000 ml with water and mix thoroughly until completely dissolved. Use the filtering device (6.6) and the filtering disc (6.5) to filter the solution into another 1 000 ml conical flask. 5.4 Sodium hydroxide solution (NaOH), c(NaOH) 1 mol/l. Use this sodi
36、um hydroxide solution for caseins and caseinates which do not dissolve completely in the other reagents. Dissolve 40 g of sodium hydroxide in water in a 1 000 ml conical flask (6.2). Dilute to 1 000 ml with water and mix thoroughly until completely dissolved. Use the filtering device (6.6) and the f
37、iltering disc (6.5) to filter the solution into another 1 000 ml conical flask. 5.5 Ethanol, of volume fraction 95 % 2 %, for caseinates. 6 Apparatus Usual laboratory equipment and, in particular, the following. 6.1 Analytical balance, capable of weighing to the nearest 0,1 g. 6.2 Conical flasks, of
38、 capacities 600 ml and 1 000 ml. 6.3 Measuring cylinders, of capacities 100 ml and 500 ml. 6.4 Water bath, capable of maintaining a temperature of 60 C 1 C. 6.5 Filtering discs, of diameter 32 mm, suitable for use in the filtering device (6.6). The filter material should preferably consist of cotton
39、, and the limit for retaining scorched particles and extraneous matter should be 5 m to 10 m. In addition, the disc shall be tested by the method specified in Annex A. 6.6 Filtering device, aspirator or pressure type, with a filtering area of diameter 28,6 mm. 6.7 Grinding device, for grinding the t
40、est sample, if necessary. To avoid loss of moisture, the device should not produce undue heat. A hammer shall not be used. 6.8 Test sieve, of metal wire cloth, with diameter 200 mm and nominal aperture size 500 m, with receiver, complying with the requirements of ISO 3310-1. 6.9 Scorched particle st
41、andard discs, indicating increasing scorched particles content by the classification letters A, B, C and D, respectively (see Figure 1 for examples). BSISO5739:2003 3Instructions for the preparation of the scorched particle standard discs, if required, are given in Annex B. NOTE Prints of the standa
42、rd discs are available from the United States Department of Agriculture, Agricultural Marketing Service, Washington DC 20250. Order by name and number 1) . Figure 1 shows examples of the discs. This illustration is not to be used for official classification of scorched particles content. 6.10 Micros
43、cope, providing a magnification of 25. Figure 1 Examples of standard scorched particle discs 7 Sampling It is important that the laboratory receive a sample which is truly representative and has not been damaged or changed during transport or storage. Sampling is not part of the method specified in
44、this International Standard. A recommended sampling method is given in ISO 707. 8 Procedure 8.1 Preparation of test sample 8.1.1 Thoroughly mix the test sample by repeatedly shaking and inverting the container. If necessary, transfer the complete test sample to an airtight container of sufficient ca
45、pacity to allow this operation to be carried out. 8.1.2 Transfer about 50 g of the thoroughly mixed test sample to the test sieve (6.8). If the amount of test sample directly passes or almost completely passes the sieve, use the test sample as prepared in 8.1.1. Proceed with the preparation of the t
46、est portion (8.2) and the determination (8.3) as soon as possible after the preparation of the sample. 8.1.3 If the 50 g test sample does not directly pass the sieve, grind the test sample by using the grinding device (6.7) until it passes the sieve. Immediately transfer all the sieved sample to an
47、airtight container of sufficient capacity and mix thoroughly by repeatedly shaking and inverting. During these operations, take all precautions to avoid any change in the moisture content of the product. Proceed with the preparation of the test portion (8.2) and the determination (8.3) as soon as po
48、ssible after the preparation of the test sample. 1) USDA scorched particle standards for dry milks, No. 7 CFR 2858 2676, is an example of a suitable product available commercially. This information is given for the convenience of users of this International Standard and does not constitute an endors
49、ement by ISO or IDF of this product. BSISO5739:20034 8.2 Test portion Weigh, to nearest 0,1 g, 25,0 g of the test sample (8.1.2 or 8.1.3) and transfer the test portion to a 600 ml flask (6.2). 8.3 Determination 8.3.1 Addition of reagent NOTE The pH of the solutions obtained in 8.3.1.1 to 8.3.1.3 and those in 8.3.3 a), b), c) might have an effect on the partial solubility of the scorched particles. The solution pH can vary due to possible pH variation of th
