EN ISO 21187:2021

Milk - Quantitative determination of microbiological quality - Guidance for establishing and verifying a conversion relationship between results of an alternative method and anchor method results (ISO 21187:2021)

This document gives guidelines for the establishment of a conversion relationship between the results of an alternative method and an anchor method, and its verification for the quantitative determination of the microbiological quality of milk.
NOTE     The conversion relationship can be used a) to convert results from an alternative method to the anchor basis or b) to convert results/limits, expressed on an anchor basis, to results in units of an alternative method.

Milch - Quantitative Bestimmung der mikrobiologischen Qualität - Leitfaden für die Erarbeitung und Verifizierung einer Übertragungsbeziehung zwischen den Ergebnissen von einem alternativen und einem Bezugsverfahren (ISO 21187:2021)

Dieses Dokument gibt Anweisungen für die Erarbeitung einer Übertragungsbeziehung zwischen den Ergebnissen eines alternativen und eines Bezugsverfahrens sowie für deren Verifizierung für die quantitative Bestimmung der mikrobiologischen Qualität von Milch.
ANMERKUNG   Die Übertragungsbeziehung kann a) zur Übertragung von Ergebnissen von einem alternativen Verfahren auf die Bezugsbasis oder b) zur Übertragung von Ergebnissen/Grenzwerten, ausgedrückt auf einer Bezugsbasis, in Ergebnisse in Einheiten eines alternativen Verfahrens verwendet werden.

Lait - Mesure quantitative de la qualité microbiologique - Lignes directrices pour établir et vérifier une relation de conversion entre les résultats de la méthode alternatif et les résultats de la méthode d’ancrage (ISO 21187:2021)

Le présent document donne des lignes directrices pour l'établissement d'une relation de conversion entre les résultats d'une méthode alternative et les résultats d'une méthode d'ancrage, et sa vérification en vue de la détermination quantitative de la qualité microbiologique du lait.
NOTE       La relation de conversion peut être utilisée a) pour convertir les résultats d'une méthode alternative sur la base de la méthode d'ancrage ou b) pour convertir les résultats/limites exprimés sur la base de la méthode d'ancrage, en résultats exprimés dans les unités d'une méthode alternative.

Mleko - Kvantitativno določanje bakteriološke kakovosti - Navodilo za ugotavljanje in preverjanje konverzijske povezave med rezultati alternativne metode in rezultati uveljavljene metode (ISO 21187:2021)

General Information

• Status: Published
• Publication Date: 09-Mar-2021
• Withdrawal Date: 29-Sep-2021
• ICS: 07.100.30 - Food microbiology
• ICS: 67.100.01 - Milk and milk products in general
• Technical Committee: CEN/TC 302 - Milk and milk products - Methods of sampling and analysis
• Drafting Committee: CEN/TC 302 - Milk and milk products - Methods of sampling and analysis
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 10-Mar-2021
• Completion Date: 10-Mar-2021
• Ref Project: SIST EN ISO 21187:2021 - Milk - Quantitative determination of microbiological quality - Guidance for establishing and verifying a conversion relationship between results of an alternative method and anchor method results (ISO 21187:2021)

Relations

• Replaces: EN ISO 21187:2005 - Milk - Quantitative determination of bacteriological quality - Guidance for establishing and verifying a conversion relationship between routine method results and anchor method results (ISO 21187:2004)
• Effective Date: 23-May-2018

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2021
Nadomešča:
SIST EN ISO 21187:2006
Mleko - Kvantitativno določanje bakteriološke kakovosti - Navodilo za ugotavljanje
in preverjanje konverzijske povezave med rezultati alternativne metode in rezultati
uveljavljene metode (ISO 21187:2021)
Milk - Quantitative determination of microbiological quality - Guidance for establishing
and verifying a conversion relationship between results of an alternative method and
anchor method results (ISO 21187:2021)
Milch - Quantitative Bestimmung der bakteriologischen Qualität - Leitfaden für die
Erarbeitung einer Übertragungsbeziehung zwischen den Messwerten von Routine- und
Bezugsverfahren sowie deren Verifizierung (ISO 21187:2021)
Lait - Mesure quantitative de la qualité bactériologique - Lignes directrices pour établir et
vérifier une relation de conversion entre les résultats de la méthode alternatif et les
résultats de la méthode d'ancrage (ISO 21187:2021)
Ta slovenski standard je istoveten z: EN ISO 21187:2021
ICS:
07.100.30 Mikrobiologija živil Food microbiology
67.100.10 Mleko in predelani mlečni Milk and processed milk
proizvodi products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 21187
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2021
EUROPÄISCHE NORM
ICS 07.100.30; 67.100.01 Supersedes EN ISO 21187:2005
English Version
Milk - Quantitative determination of microbiological
quality - Guidance for establishing and verifying a
conversion relationship between results of an alternative
method and anchor method results (ISO 21187:2021)
Lait - Mesure quantitative de la qualité Milch - Quantitative Bestimmung der bakteriologischen
microbiologique - Lignes directrices pour établir et Qualität - Leitfaden für die Erarbeitung einer
vérifier une relation de conversion entre les résultats Übertragungsbeziehung zwischen den Messwerten von
de la méthode alternatif et les résultats de la méthode Routine- und Bezugsverfahren sowie deren
d'ancrage (ISO 21187:2021) Verifizierung (ISO 21187:2021)
This European Standard was approved by CEN on 4 December 2020.

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 alteration. 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
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,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 21187:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 21187:2021) has been prepared by Technical Committee ISO/TC 34 "Food
products" in collaboration with Technical Committee CEN/TC 302 “Milk and milk products - Methods of
sampling and analysis” the secretariat of which is held by NEN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2021, and conflicting national standards
shall be withdrawn at the latest by September 2021.
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 all such patent rights.
This document supersedes EN ISO 21187:2005.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 21187:2021 has been approved by CEN as EN ISO 21187:2021 without any modification.

INTERNATIONAL ISO
STANDARD 21187
IDF 196
Second edition
2021-02
Milk — Quantitative determination of
microbiological quality — Guidance
for establishing and verifying a
conversion relationship between
results of an alternative method and
anchor method results
Lait — Mesure quantitative de la qualité microbiologique — Lignes
directrices pour établir et vérifier une relation de conversion entre
les résultats de la méthode alternatif et les résultats de la méthode
d’ancrage
Reference numbers
ISO 21187:2021(E)
IDF 196:2021(E)
©
ISO and IDF 2021
ISO 21187:2021(E)
IDF 196:2021(E)
© ISO and IDF 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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 at the address
below or ISO’s member body in the country of the requester.
ISO copyright office International Dairy Federation
CP 401 • Ch. de Blandonnet 8 Silver Building • Bd Auguste Reyers 70/B
CH-1214 Vernier, Geneva B-1030 Brussels
Phone: [phone] Phone: [phone]
Fax: [phone]
Email: [e-mail] Email: [e-mail]
Website: www.iso.org Website: www.fil-idf.org
Published in Switzerland
ii © ISO and IDF 2021 – All rights reserved

ISO 21187:2021(E)
IDF 196:2021(E)
Contents Page
Foreword .v
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles . 2
4.1 General . 2
4.2 Guidance for applied methods and laboratories . 2
4.3 Organizational set-up . 3
5 Consideration of factors influencing the conversion relationship . 3
5.1 General . 3
5.2 Environmental factors . 3
5.2.1 General. 3
5.2.2 Animal species . 4
5.2.3 Bulk milk storage conditions . 4
5.2.4 Seasonal variations . 4
5.2.5 Sampling and pre-treatment of the test samples . 4
5.2.6 Test sample preservation . 4
5.2.7 Milk production conditions . 4
5.3 Analytical factors . 5
5.3.1 Instrument make and model . 5
5.3.2 Chemicals . 5
5.3.3 High somatic cell counts . 5
6 Test samples . 5
6.1 Calculation of number of test samples . 5
6.2 Range of test samples . 6
6.3 Representativeness of samples . 6
6.4 Pre-treatment of test samples . 6
6.4.1 General. 6
6.4.2 Preparation of sub-samples . 6
6.4.3 Storage and transport of sub-samples . 7
7 Analysis . 7
8 Establishing a conversion relationship . 7
8.1 General . 7
8.2 Validity of results . 7
8.3 Conversion relationship . 8
8.4 Calculations . 8
8.4.1 General. 8
8.4.2 Removal of outliers . 8
8.4.3 Conv
...