ISO INTERNATIONAL STANDARD 11815 IDF 157 First edition 2007-07-01 Milk Determination of total milk-clotting activity of bovine rennets Lait - Détermination de I'activite totale de coagulation du lait dans la présure de bovins Reference numbers ISO 11815:2007(E) IDF 157:2007(E) @ ISO and IDF 2007 IHSunder Not for Resale ISO 11815:2007(E) IDF157:2007(E) PDFdisclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. Neither the ISo Central Secretariat nor the IDF accepts any liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation and IDF national committees. In the unlikely event that a problem relating to it is found, please inform the ISO Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT @ ISO and IDF 2007 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, address below. ISO copyright office International DairyFederation Case postale 56 . CH-1211 Geneva 20 Diamant Building·Boulevard Auguste Reyers 80.B-1030 Brussels Tel. + 4122 749 01 11 Tel. + 32 2 733 98 88 Fax + 41 22 749 09 47 Fax + 32 2 733 04 13 E-mail [email protected] E-mail [email protected] Web www.iso.org Web www.fil-idf.org Published in Switzerland @ ISO and IDF 2007 - All rights reserved ted without license from IHS Not for Resale ISO 11815:2007(E) IDF157:2007(E) Contents Page Foreword. Foreword. Introduction 1 Scope 2 Normative reference 3 Terms and definition 4 Principle 5 Reagents 6 Apparatus 7 Sampling. 8 Preparation of test sample.... 8.1 Liquid rennet .. 8.2 Powdered rennet.. 9 Procedure... 9.1 Preparation of substrate 9.2 Preparation of rennet reference standard solutions... 9.3 Preparation of the calf and adult bovine rennet reference working solutions. 9.4 Preparation of rennet test solution ... 9.5 Clotting .... 10 Calculation and expression of results. 10.1 Calculation.... 10.2 Expression of results .... 11 Precision... 11.1 Interlaboratory test 8 11.2 Repeatability.. 11.3 Reproducibility. 8 12 Test report. 9 Annex A (informative) Interlaboratory trial.. Bibliography ii se from IHS Not for Resale ISO 11815:2007(E) IDF 157:2007(E) 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 ISOtechnicalcommittees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehas 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 Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2. 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 subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO 11815liDF 157 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 jointly by ISO and IDF. ional Organization for Standardiza