DIN EN ISO 21528-2-2017 Microbiology of the food chain - Horizontal method for the detection and enumeration of Enterobacteriaceae - Part 2 Colony-count technique (ISO 21528-2 2017.pdf

1、September 2017 English price group 13No part of this translation 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 07.100.30!%mPk“2744572www.din.

2、deDIN EN ISO 21528-2Microbiology of the food chain Horizontal method for the detection and enumeration of Enterobacteriaceae Part 2: Colonycount technique (ISO 215282:2017);English version EN ISO 215282:2017,English translation of DIN EN ISO 21528-2:2017-09Mikrobiologie der Lebensmittelkette Horizon

3、tales Verfahren fr den Nachweis und die Zhlung von Enterobacteriaceae Teil 2: Koloniezhlverfahren (ISO 215282:2017);Englische Fassung EN ISO 215282:2017,Englische bersetzung von DIN EN ISO 21528-2:2017-09Microbiologie de la chane alimentaire Mthode horizontale pour la recherche et le dnombrement des

4、 Entrobacteriaceae Partie 2: Technique par comptage des colonies (ISO 215282:2017);Version anglaise EN ISO 215282:2017,Traduction anglaise de DIN EN ISO 21528-2:2017-09SupersedesDIN ISO 215282:200912www.beuth.deDocument comprises 24 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the Germa

5、n-language original shall be considered authoritative.08.17 DIN EN ISO 21528-2:2017-09 2 A comma is used as the decimal marker. National foreword This document (EN ISO 21528-2:2017) has been prepared by Technical Committee ISO/TC 34 “Food products” in collaboration with Technical Committee CEN/TC 27

6、5 “Food analysis Horizontal methods” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was DIN-Normenausschuss Lebensmittel und landwirtschaftliche Produkte (DIN Standards Committee Food and Agricultural Products), Working Committee NA 057-01-06 AA “Microbiology of

7、 the food chain”. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 6887 (all parts) DIN EN ISO 6887 (all parts) ISO 7218 DIN EN ISO 7218 ISO 11133 DIN EN ISO 11133 ISO 18593 DIN ISO 18593 ISO 5725-2:1994 DIN ISO 5725-2:2002-12 ISO 13307

8、DIN EN ISO 13307 ISO 17468 DIN EN ISO 17468 ISO 17604 DIN EN ISO 17604 ISO/TS 17728 DIN CEN ISO/TS 17728 (DIN SPEC 10053) ISO 21528-1 DIN EN ISO 21528-1 Amendments This standard differs from DIN ISO 21528-2:2009-12 as follows: a) the confirmation step has been changed by replacing glucose agar by Gl

9、ucose OF medium; b) precision data based on the results of an interlaboratory study using the method according to this revised edition has been included in an informative annex; c) the document has been editorially revised. Previous editions DIN ISO 21528-2: 2009-12 DIN EN ISO 21528-2:2017-09 3 Nati

10、onal Annex NA (informative) Bibliography DIN CEN ISO/TS 17728 (DIN SPEC 10053), Microbiology of the food chain Sampling techniques for microbiological analysis of food and feed samples DIN EN ISO 6887 (all parts), Microbiology of the food chain Preparation of test samples, initial suspension and dec

11、imal dilutions for microbiological examination DIN EN ISO 7218, Microbiology of food and animal feeding stuffs General requirements and guidance for microbiological examinations DIN EN ISO 11133, Microbiology of food, animal feed and water Preparation, production, storage and performance testing of

12、culture media DIN EN ISO 13307, Microbiology of food and animal feed Primary production stage Sampling techniques DIN EN ISO 17468, Microbiology of the food chain Technical requirements and guidance on establishment or revision of a standardized reference method DIN EN ISO 17604, Microbiology of the

13、 food chain Carcass sampling for microbiological analysis DIN EN ISO 21528-1, Microbiology of the food chain Horizontal method for the detection and enumeration of Enterobacteriaceae Part 1: Detection of Enterobacteriaceae DIN ISO 5725-2, Accuracy (trueness and precision) of measurement methods and

14、results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method DIN ISO 18593, Microbiology of food and animal feeding stuffs Horizontal methods for sampling techniques from surfaces using contact plates and swabs DIN EN ISO 21528-2:2017-09 4

15、This page is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 21528-2 July 2017 ICS 07.100.30 English Version Microbiology of the food chain - Horizontal method for the detection and enumeration of Enterobacteriaceae - Part 2: Colony-count technique (ISO 21528-2:2017) Mic

16、robiologie de la chane alimentaire - Mthode horizontale pour la recherche et le dnombrement des Enterobacteriaceae - Partie 2: Technique par comptage des colonies (ISO 21528-2:2017) Mikrobiologie der Lebensmittelkette - Horizontales Verfahren fr den Nachweis und die Zhlung von Enterobacteriaceae - T

17、eil 2: Koloniezhlverfahren(ISO 21528-2:2017) This European Standard was approved by CEN on 27 April 2017. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteratio

18、n. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by

19、translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, F

20、inland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR ST

21、ANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 21528-2:2017 EEuropean foreword .

22、3Introduction 51 Scope . 62 Normative references 63 Terms and definitions . 64 Principle 74.1 Preparation of initial suspension and decimal dilutions 74.2 Isolation and selection for confirmation 74.3 Confirmation . 74.4 Calculation 75 Diluent, culture media and reagent 76 Equipment and consumables

23、77 Sampling 88 Preparation of test sample . 89 Procedure. 89.1 General . 89.2 Test portion, initial suspension and dilutions 99.3 Inoculation and incubation 99.4 Counting and selection of colonies for confirmation . 99.5 Subculturing selected colonies 99.6 Biochemical confirmation tests . 109.6.1 Ox

24、idase reaction 109.6.2 Fermentation test . 109.6.3 Interpretation of biochemical tests 1010 Expression of results . 1011 Performance characteristics of the method 1011.1 Interlaboratory study . 1011.2 Repeatability limit . 1011.3 Reproducibility limit . 1112 Test report 1113 Quality assurance . 12An

25、nex A (normative) Culture media and reagents . 13Annex B (informative) Method validation studies and performance characteristics 17Bibliography .20Contents PageDIN EN ISO 21528-2:2017-09 EN ISO 21528-2:2017 (E) 2Foreword .4European foreword This document (EN ISO 21528-2:2017) has been prepared by Te

26、chnical Committee ISO/TC 34 “Food products” in collaboration with Technical Committee CEN/TC 275 “Food analysis - Horizontal methods” the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by end

27、orsement, at the latest by January 2018 and conflicting national standards shall be withdrawn at the latest by January 2018. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or

28、all such patent rights. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this Euro

29、pean Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slova

30、kia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 21528-2:2017 has been approved by CEN as EN ISO 21528-2:2017 without any modification. DIN EN ISO 21528-2:2017-09 EN ISO 21528-2:2017 (E) 3 ForewordISO (the International Organization for Sta

31、ndardization) 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 member body interested in a subject for which a technical committee has been established has the righ

32、t 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.The procedures

33、used to develop 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 rule

34、s of the ISO/IEC 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 iden

35、tified 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).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanati

36、on on the meaning 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: www .iso .org/ iso/ foreword .html.This document was prepared by the European Co

37、mmittee for Standardization (CEN) Technical Committee CEN/TC 275, Food analysis Horizontal methods, in collaboration with ISO Technical Committee ISO/TC 34, Food products, Subcommittee SC 9, Microbiology in accordance with the agreement on technical cooperation between ISO and CEN (Vienna Agreement)

38、.This second edition cancels and replaces the first edition (ISO 21528-2:2004), which has been technically revised with the following main changes: the confirmation step has been changed by replacing glucose agar by glucose OF medium; precision data based on the results of an interlaboratory study u

39、sing the method according to this revised edition has been included in an informative annex.A list of all the parts in the ISO 21528 series can be found on the ISO website. DIN EN ISO 21528-2:2017-09 EN ISO 21528-2:2017 (E) 4 IntroductionThis document is intended to provide general guidance for the

40、examination of products not dealt with by existing International Standards and to be taken into account by organizations preparing microbiological test methods for application to foods or animal feeding stuffs. Because of the large variety of products within this field of application, these guidelin

41、es may not be appropriate in every detail for certain products, and for some other products, it may be necessary to use different methods. Nevertheless, it is hoped that in all cases, every attempt will be made to apply the guidelines provided as far as possible and that deviations from them will on

42、ly be made if absolutely necessary for technical reasons.The main changes, listed in the foreword, introduced in this document compared to ISO 21528-2:2004, are considered as minor changes (see ISO 17468).The harmonization of test methods cannot be immediate, and for certain groups of products, Inte

43、rnational Standards and/or national standards may already exist that do not comply with this horizontal method. It is hoped that when such standards are reviewed, they will be changed to comply with this document so that eventually the only remaining departures from this horizontal method will be th

44、ose necessary for well-established technical reasons.DIN EN ISO 21528-2:2017-09 EN ISO 21528-2:2017 (E) 5 WARNING In order to safeguard the health of laboratory personnel, it is essential that tests for detecting Enterobacteriaceae are only undertaken in properly equipped laboratories, under the con

45、trol of a skilled microbiologist, and that great care is taken in the disposal of all incubated materials. Persons using this document should be familiar with normal laboratory practice. This document does not purport to address all of the safety aspects, if any, associated with its use. It is the r

46、esponsibility of the user to establish appropriate safety and health practices.1 ScopeThis document specifies a method for the enumeration of Enterobacteriaceae. It is applicable to products intended for human consumption and the feeding of animals, and environmental samples in the area of primary p

47、roduction, food production and food handling.This technique is intended to be used when the number of colonies sought is expected to be more than 100 per millilitre or per gram of the test sample.The most probable number (MPN) technique, as included in ISO 21528-1, is generally used when the number

48、sought is expected to be below 100 per millilitre or per gram of test sample.2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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 6887 (all parts), Microbiology of the food chain Preparation of test samples, initial suspension