SIST EN ISO 6887-4:2017

Microbiology of the food chain - Preparation of test samples, initial suspension and decimal dilutions for microbiological examination - Part 4: Specific rules for the preparation of miscellaneous products (ISO 6887-4:2017)

This document specifies rules for the preparation of samples and dilutions for the microbiological
examination of specific food products not covered in other parts of ISO 6887, which deal with more
general categories. This document covers a wide range of miscellaneous products, but does not include
new products brought on to the market after publication.
ISO 6887-1 defines the general rules for the preparation of the initial suspension and dilutions for
microbiological examination.
This document excludes preparation of samples for both enumeration and detection test methods when
preparation details are specified in the relevant International Standards.
This document is applicable to the following products:
— acidic (low pH) products;
— hard and dry products;
— dehydrated, freeze-dried and other low aw products (including those with inhibitory properties);
— flours, whole cereal grains, cereal by-products;
— animal feed, cattle cake, kibbles and pet chews;
— gelatine (powdered and leaf);
— margarines, spreads and non-dairy products with added water;
— eggs and egg products;
— bakery goods, pastries and cakes;
— fresh fruit and vegetables;
— fermented products and other products containing viable microorganisms;
— alcoholic and non-alcoholic beverages;
— alternative protein products.

Mikrobiologie der Lebensmittelkette - Vorbereitung von Untersuchungsproben und Herstellung von Erstverdünnungen und von Dezimalverdünnungen für mikrobiologische Untersuchungen - Teil 4: Spezifische Regeln für die Vorbereitung von sonstigen Erzeugnissen (ISO 6887-4:2017)

Dieses Dokument legt Regeln für die Vorbereitung von Proben und Verdünnungen für mikrobiologische Untersuchungen von speziellen Lebensmittelerzeugnissen fest, die nicht in den anderen Teilen von ISO 6887 erfasst sind, in denen allgemeinere Kategorien behandelt werden. Dieses Dokument erfasst ein breites Spektrum verschiedener Produkte, schließt jedoch keine neuen Produkte ein, die nach der Veröffentlichung auf den Markt gebracht wurden.
Die ISO 6887-1 legt die allgemeinen Regeln für die Herstellung der Erstverdünnung und Verdünnungen für mikrobiologische Untersuchungen fest.
Dieses Dokument schließt die Vorbereitung von Proben für Prüfverfahren sowohl zur Zählung als auch zum Nachweis aus, bei denen die Einzelheiten zur Vorbereitung in den betreffenden Internationalen Normen festgelegt sind.
Dieser Teil von ISO 6887 gilt für folgende Produkte:
—   saure Produkte (mit niedrigem pH Wert);
—   harte und trockene Produkte;
—   Trockenprodukte, gefriergetrocknete Produkte und andere Produkte mit geringer Wasseraktivität (aw) (einschließlich derer mit (keim )hemmenden Eigenschaften);
—   Mehl, ganze Getreidekörner, Getreidenebenprodukte;
—   Tierfutter, Futterkuchen für Rinder, Trockenfutter und Kauartikel für Heimtiere;
—   Gelatine (in Pulver  und Blattform);
—   Margarine, Streichfette und milchfreie Produkte mit hinzugefügtem Wasser;
—   Eier und Eiprodukte;
—   Backwaren, Gebäck und Kuchen;
—   frisches Obst und Gemüse;
—   gereifte/fermentierte Produkte und andere lebende Mikroorganismen enthaltende Produkte;
—   alkoholische und nicht alkoholische Getränke;
—   alternative Proteinprodukte.

Microbiologie de la chaîne alimentaire - Préparation des échantillons, de la suspension mère et des dilutions décimales en vue de l'examen microbiologique - Partie 4: Règles spécifiques pour la préparation de produits variés (ISO 6887-4:2017)

ISO 6887-4:2017 spécifie les règles de préparation d'échantillons et de dilutions pour l'examen microbiologique de produits alimentaires spécifiques non concernés par les autres parties de l'ISO 6887 qui ont trait à des catégories plus générales. Le présent document concerne une vaste gamme de produits variés mais ne comprend pas les nouveaux produits commercialisés après la date de publication.
L'ISO 6887‑1 définit les règles générales de préparation de la suspension mère et des dilutions en vue de l'examen microbiologique.
ISO 6887-4:2017 exclut la préparation d'échantillons en vue des méthodes de dénombrement et de recherche lorsque les détails de préparation sont spécifiés dans les Normes internationales applicables.
ISO 6887-4:2017 est applicable aux produits suivants:
-      produits acides (faible pH);
-      produits durs et secs;
-      produits déshydratés, lyophilisés et autres produits à faible activité aw (notamment ceux ayant des propriétés inhibitrices);
-      farines, grains de céréales entiers, produits céréaliers dérivés;
-      aliments pour animaux, tourteaux, croquettes et os à mâcher;
-      gélatine (en poudre et en feuilles);
-      margarines, produits à tartiner et produits non laitiers contenant de l'eau;
-      ?ufs et ovoproduits;
-      produits de boulangerie, pâtisseries et gâteaux;
-      fruits et légumes frais;
-      produits fermentés et autres produits contenant des micro-organismes vivants;
-      boissons alcoolisées et non alcoolisées;
-      autres produits à base de protéines.

Mikrobiologija v prehranski verigi - Priprava preskusnih vzorcev, osnovne suspenzije in decimalnih razredčin za mikrobiološko preiskavo - 4. del: Posebna pravila za pripravo drugih izdelkov (ISO 6887-4:2017)

Ta dokument določa pravila za pripravo vzorcev in raztopin za mikrobiološko preiskavo posebnih prehranskih izdelkov, ki niso zajeti v drugih delih standarda ISO 6887, ki obravnavajo bolj splošne kategorije. Ta dokument zajema širok nabor različnih izdelkov, vendar ne vključuje novih izdelkov, ki pridejo na trg po objavi.
Standard ISO 6887-1 določa splošna pravila za pripravo osnovnih razredčin za mikrobiološko preiskavo.
Ta dokument ne zajema priprave vzorcev za preskusni metodi za ugotavljanje števila in odkrivanje, kadar so podrobnosti glede priprave opredeljene v ustreznih mednarodnih standardih.
Ta dokument se uporablja za naslednje izdelke:
– kisli izdelki (nizek pH);
– trdi in suhi izdelki;
– dehidrirani, liofilizirani in drugi izdelki z nizko vrednostjo aw (vključno z izdelki z zaviralnimi lastnostmi);
– moke, cela žitna zrnja, stranski proizvodi iz žit;
– krma za živali, pogače za govedo, briketi in priboljški za žvečenje;
– želatina (v prahu in v lističih);
– margarine, namazi in nemlečni izdelki z dodano vodo;
– jajca in jajčni izdelki;
– pekovski izdelki, peciva in torte;
– sveže sadje in zelenjava;
– fermentirani izdelki in drugi izdelki, ki vsebujejo žive mikroorganizme;
– alkoholne in nealkoholne pijače;
– alternativni beljakovinski izdelki.

General Information

• Status: Published
• Public Enquiry End Date: 09-Mar-2014
• Publication Date: 16-May-2017
• ICS: 07.100.30 - Food microbiology
• Technical Committee: KŽP - Agricultural food products
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 25-Apr-2017
• Due Date: 30-Jun-2017
• Completion Date: 17-May-2017
• Ref Project: EN ISO 6887-4:2017 - Microbiology of the food chain - Preparation of test samples, initial suspension and decimal dilutions for microbiological examination - Part 4: Specific rules for the preparation of miscellaneous products (ISO 6887-4:2017, Corrected version 2021-03)

Relations

• Replaces: SIST EN ISO 6887-4:2003/A1:2012 - Microbiology of food and animal feeding stuffs - Preparation of test samples, initial suspension and decimal dilutions for microbiological examination - Part 4: Specific rules for the preparation of products other than milk and milk products, meat and meat products, and fish and fishery products (ISO 6887-4:2003/Amd 1:2011)
• Effective Date: 01-Jun-2017
• Replaces: SIST EN ISO 6887-4:2003/AC:2005 - Microbiology of food and animal feeding stuffs - Preparation of test samples, initial suspension and decimal dilutions for microbiological examination - Part 4: Specific rules for the preparation of products other than milk and milk products, meat and meat products, and fish and fishery products (ISO 6887-4:2003)
• Effective Date: 01-Jun-2017
• Replaces: SIST EN ISO 6887-4:2003 - Microbiology of food and animal feeding stuffs - Preparation of test samples, initial suspension and decimal dilutions for microbiological examination - Part 4: Specific rules for the preparation of products other than milk and milk products, meat and meat products, and fish and fishery products (ISO 6887-4:2003)
• Effective Date: 01-Jun-2017
• Replaces: SIST EN ISO 6887-4:2003/A1:2012 - Microbiology of food and animal feeding stuffs - Preparation of test samples, initial suspension and decimal dilutions for microbiological examination - Part 4: Specific rules for the preparation of products other than milk and milk products, meat and meat products, and fish and fishery products (ISO 6887-4:2003/Amd 1:2011)
• Effective Date: 08-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 6887-4:2017
01-junij-2017
1DGRPHãþD
SIST EN ISO 6887-4:2003
SIST EN ISO 6887-4:2003/A1:2012
SIST EN ISO 6887-4:2003/AC:2005
0LNURELRORJLMDYSUHKUDQVNLYHULJL3ULSUDYDSUHVNXVQLKY]RUFHYRVQRYQH
VXVSHQ]LMHLQGHFLPDOQLKUD]UHGþLQ]DPLNURELRORãNRSUHLVNDYRGHO3RVHEQD
SUDYLOD]DSULSUDYRGUXJLKL]GHONRY,62
Microbiology of the food chain - Preparation of test samples, initial suspension and
decimal dilutions for microbiological examination - Part 4: Specific rules for the
preparation of miscellaneous products (ISO 6887-4:2017)
Mikrobiologie der Lebensmittelkette - Vorbereitung von Untersuchungsproben und
Herstellung von Erstverdünnungen und von Dezimalverdünnungen für mikrobiologische
Untersuchungen - Teil 4: Spezifische Regeln für die Vorbereitung von sonstigen
Erzeugnissen (ISO 6887-4:2017)
Microbiologie de la chaîne alimentaire - Préparation des échantillons, de la suspension
mère et des dilutions décimales en vue de l'examen microbiologique - Partie 4: Règles
spécifiques pour la préparation de produits variés (ISO 6887-4:2017)
Ta slovenski standard je istoveten z: EN ISO 6887-4:2017
ICS:
07.100.30 Mikrobiologija živil Food microbiology
SIST EN ISO 6887-4:2017 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 6887-4:2017

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SIST EN ISO 6887-4:2017


EN ISO 6887-4
EUROPEAN STANDARD

NORME EUROPÉENNE

April 2017
EUROPÄISCHE NORM
ICS 07.100.30 Supersedes EN ISO 6887-4:2003
English Version

Microbiology of the food chain - Preparation of test
samples, initial suspension and decimal dilutions for
microbiological examination - Part 4: Specific rules for the
preparation of miscellaneous products (ISO 6887-4:2017)
Microbiologie de la chaîne alimentaire - Préparation Mikrobiologie der Lebensmittelkette - Vorbereitung
des échantillons, de la suspension mère et des dilutions von Untersuchungsproben und Herstellung von
décimales en vue de l'examen microbiologique - Partie Erstverdünnungen und von Dezimalverdünnungen für
4: Règles spécifiques pour la préparation de produits mikrobiologische Untersuchungen - Teil 4: Spezifische
variés (ISO 6887-4:2017) Regeln für die Vorbereitung von sonstigen
Erzeugnissen (ISO 6887-4:2017)
This European Standard was approved by CEN on 14 January 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 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, 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 STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR 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 Ref. No. EN ISO 6887-4:2017 E
worldwide for CEN national Members.

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SIST EN ISO 6887-4:2017
EN ISO 6887-4:2017 (E)
Contents Page
European foreword . 3

2

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SIST EN ISO 6887-4:2017
EN ISO 6887-4:2017 (E)
European foreword
This document (EN ISO 6887-4:2017) has been prepared by Technical 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 endorsement, at the latest by October 2017, and conflicting national standards shall
be withdrawn at the latest by October 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes EN ISO 6887-4:2003.
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, 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 the United Kingdom.
Endorsement notice
The text of ISO 6887-4:2017 has been approved by CEN as EN ISO 6887-4:2017 without any
modification.

3

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SIST EN ISO 6887-4:2017

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SIST EN ISO 6887-4:2017
INTERNATIONAL ISO
STANDARD 6887-4
Second edition
2017-03
Microbiology of the food chain —
Preparation of test samples, initial
suspension and decimal dilutions for
microbiological examination —
Part 4:
Specific rules for the preparation of
miscellaneous products
Microbiologie de la chaîne alimentaire — Préparation des
échantillons, de la suspension mère et des dilutions décimales en vue
de l’examen microbiologique —
Partie 4: Règles spécifiques pour la préparation de produits variés
Reference number
ISO 6887-4:2017(E)
©
ISO 2017

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SIST EN ISO 6887-4:2017
ISO 6887-4:2017(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise 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 at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2017 – All rights reserved

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SIST EN ISO 6887-4:2017
ISO 6887-4:2017(E)

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Principle . 2
5 Diluents . 2
5.1 Basic materials . 2
5.2 Diluents for general use . 2
5.2.1 Peptone salt solution . 2
5.2.2 Buffered peptone water . 2
5.3 Diluents for special purposes . 3
5.3.1 Double-strength buffered peptone water . 3
5.3.2 Phosphate buffered diluent . 3
5.4 Distribution and sterilization of the diluent . 3
5.5 Performance testing of diluents . 3
5.6 Enzyme solutions . 3
5.6.1 Alpha-amylase solution . . 3
5.6.2 Cellulase solution . 4
5.6.3 Papain solution . 4
6 Apparatus . 4
7 Sampling and sample types . 5
8 Preparation of samples. 5
8.1 General . 5
8.2 Acidic products . 5
8.3 High-fat foods, excluding margarines and spreads (e.g. over 20 % of total mass as fat) . 6
8.4 Hard and dry products . 6
9 Specific procedures. 6
9.1 Dehydrated and low a products . 6
w
9.1.1 General. 6
9.1.2 Apparatus . 6
9.1.3 Preparation of samples . 7
9.1.4 Preparation of initial suspension . 7
9.1.5 Resuscitation . 8
9.1.6 Water activity . 8
9.2 Flours, cereal grains and by-products and animal feeds . 9
9.3 Gelatine (powdered and leaf) .10
9.3.1 Preparation of samples .10
9.3.2 Preparation of initial suspension .10
9.4 Margarine and spreads .10
9.4.1 Sampling.10
9.4.2 Preparation of test sample .11
9.5 Eggs and egg products .11
9.5.1 Fresh whole eggs .11
9.5.2 Microflora of whole egg shell .12
9.5.3 Internal microflora .12
9.5.4 Bulk whole liquid egg, egg white and egg yolk .12
9.5.5 Dehydrated whole egg and dried egg white .12
9.5.6 Whole egg microflora (shell plus yolk plus white) .12
9.6 Bakery goods, pastry and cakes .13
9.6.1 General.13
9.6.2 Preparation of samples .13
© ISO 2017 – All rights reserved iii

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SIST EN ISO 6887-4:2017
ISO 6887-4:2017(E)

9.7 Fresh fruit and vegetables (pre-packed) .13
9.7.1 Sample preparation of multi-component products .13
9.7.2 Pre-packed products of one type of fruit or vegetable.13
9.8 Fermented products or other products containing viable microorganisms .13
9.8.1 General.13
9.8.2 Diluent .14
9.9 Beverages (alcoholic and non-alcoholic drinks and bottled waters, still or carbonated) .14
9.9.1 General.14
9.9.2 De-gassing by inversion and mixing .14
9.9.3 De-gassing using ultrasound .14
9.10 Alternative protein products (cooked insects, textured vegetable protein
or mycoprotein) .14
9.10.1 General.14
9.10.2 Cooked insects .14
9.10.3 Textured vegetable protein and mycoprotein .15
10 Further dilutions .15
Bibliography .16
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SIST EN ISO 6887-4:2017
ISO 6887-4:2017(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 ISO technical committees. Each member 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 Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures 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 rules 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 identified 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 explanation on the meaning of ISO specific terms and expressions related to conformity assessment,
as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the
Technical Barriers to Trade (TBT) see the following URL: www . i so .org/ iso/ foreword .html.
The committee responsible for this document is ISO/TC 34, Food products, Subcommittee SC 9,
Microbiology.
This second edition cancels and replaces the first edition (ISO 6887-4:2003), which has been technically
revised.
It also incorporates the Amendment ISO 6887-4:2003/Amd.1:2011 and the Technical Corrigendum
ISO 6887-4:2003/Cor.1:2004.
A list of all parts in the ISO 6887 series can be found on the ISO website.
© ISO 2017 – All rights reserved v

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SIST EN ISO 6887-4:2017

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SIST EN ISO 6887-4:2017
INTERNATIONAL STANDARD ISO 6887-4:2017(E)
Microbiology of the food chain — Preparation of test
samples, initial suspension and decimal dilutions for
microbiological examination —
Part 4:
Specific rules for the preparation of miscellaneous
products
WARNING — The use of this document may involve hazardous materials, operations and
equipment. It is the responsibility of the user of this document to establish appropriate safety
and health practices and to determine the applicability of regulatory limitations before use.
1 Scope
This document specifies rules for the preparation of samples and dilutions for the microbiological
examination of specific food products not covered in other parts of ISO 6887, which deal with more
general categories. This document covers a wide range of miscellaneous products, but does not include
new products brought on to the market after publication.
ISO 6887-1 defines the general rules for the preparation of the initial suspension and dilutions for
microbiological examination.
This document excludes preparation of samples for both enumeration and detection test methods when
preparation details are specified in the relevant International Standards.
This document is applicable to the following products:
— acidic (low pH) products;
— hard and dry products;
— dehydrated, freeze-dried and other low a products (including those with inhibitory properties);
w
— flours, whole cereal grains, cereal by-products;
— animal feed, cattle cake, kibbles and pet chews;
— gelatine (powdered and leaf);
— margarines, spreads and non-dairy products with added water;
— eggs and egg products;
— bakery goods, pastries and cakes;
— fresh fruit and vegetables;
— fermented products and other products containing viable microorganisms;
— alcoholic and non-alcoholic beverages;
— alternative protein products.
© ISO 2017 – All rights reserved 1

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SIST EN ISO 6887-4:2017
ISO 6887-4:2017(E)

2 Normative references
The 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 6887-1, Microbiology of the food chain — Preparation of test samples, initial suspension and decimal
dilutions for microbiological examination — Part 1: General rules for the preparation of the initial
suspension and decimal dilutions
ISO 7218, Microbiology of food and animal feeding stuffs — General requirements and guidance for
microbiological examinations
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 6887-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp/
4 Principle
The general principles for sample preparation and subsequent steps are detailed in ISO 6887-1. This
document describes specific measures for products not covered in other parts of ISO 6887.
An initial suspension is prepared to obtain as uniform a distribution as possible of the microorganisms
contained in the test portion.
For detection methods, the pre-enrichment or enrichment suspension is prepared in the same way,
using the medium recommended in the method of examination concerned. For enumeration methods
used for all food types covered in this document, general diluents are documented in the relevant
clauses of ISO 6887-1 and specific diluents are included in Clause 5.
If necessary, further dilutions are prepared in order to reduce the number of microorganisms per unit
volume to allow, after incubation, observation of any growth (in the case of liquid media) or colonies (in
the case of agar plates or agar tubes) as stated in each specific standard.
5 Diluents
5.1 Basic materials
Refer to ISO 6887-1.
5.2 Diluents for general use
5.2.1 Peptone salt solution
Refer to ISO 6887-1.
5.2.2 Buffered peptone water
Refer to ISO 6887-1.
2 © ISO 2017 – All rights reserved

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SIST EN ISO 6887-4:2017
ISO 6887-4:2017(E)

5.3 Diluents for special purposes
5.3.1 Double-strength buffered peptone water
5.3.1.1 Composition and preparation
Refer to ISO 6887-1.
5.3.1.2 Application
Use this diluent for highly acidic products of pH ≥ 3,5 to pH ˂ 4,5 to obtain an initial suspension of pH
7,0 ± 0,5.
NOTE Buffered peptone water (5.2.2) is sufficient for products of pH 4,5 and above.
5.3.2 Phosphate buffered diluent
5.3.2.1 Composition
Disodium hydrogen phosphate dodecahydrate 9,0 g
(Na HPO · 12H O)
2 4 2
Potassium dihydrogen phosphate (KH PO ) 1,5 g
2 4
Water 1 000 ml
5.3.2.2 Preparation
Dissolve the components in the water, by heating if necessary.
If necessary, adjust the pH so that, after sterilization, it is pH 7,0 ± 0,2 at 25 °C.
5.3.2.3 Application
Phosphate buffered solution is used as a diluent for gelatine (9.3).
5.4 Distribution and sterilization of the diluent
Refer to ISO 6887-1.
5.5 Performance testing of diluents
Refer to ISO 6887-1.
5.6 Enzyme solutions
5.6.1 Alpha-amylase solution
5.6.1.1 Composition
α-amylase 1,0 g
Water 100 ml
© ISO 2017 – All rights reserved 3

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SIST EN ISO 6887-4:2017
ISO 6887-4:2017(E)

5.6.1.2 Preparation
Dissolve the α-amylase in the water and sterilize the solution by passing through a 0,2 µm membrane
filter. The enzyme solution can be stored for up to 1 month at 5 °C ± 3 °C or up to 3 months at ≤−20 °C.
Final composition of the α-amylase solution may need to be adjusted depending on the enzymatic
activity of the commercial α-amylase used and the thickening properties of the test sample.
5.6.1.3 Application
This enzyme solution is added at the rate of 10 ml to 1 000 ml of diluent (1 % volume fraction) to
improve solubility of swelling starch products, cereals and cereal-containing products (9.1.4.3).
5.6.2 Cellulase solution
5.6.2.1 Composition
Cellulase 1,0 g
Water 100 ml
5.6.2.2 Preparation
Dissolve the cellulase in the water and sterilize the solution by passing through a 0,2 µm membrane
filter. The enzyme solution can be stored for up to two weeks at 5 °C ± 3 °C or up to 1 month at ≤−20 °C.
NOTE Use of fresh solution will ensure maximum enzyme activity.
5.6.2.3 Application
This enzyme solution is added at the rate of 10 ml to 1 000 ml of diluent (1 % volume fraction) to
improve solubility of carboxymethyl cellulose, locust beans, carob, guar and cassia gums (9.1.4.3).
5.6.3 Papain solution
5.6.3.1 Composition
Papain 5,0 g
Water 100 ml
5.6.3.2 Preparation
Dissolve the papain in the water and sterilize the solution by passing through a 0,2 µm membrane filter.
The enzyme solution can be stored for up to 1 month at 5 °C ± 3 °C.
NOTE Use of fresh solution will ensure maximum enzyme activity.
5.6.3.3 Application
This enzyme solution is added at the rate of 20 ml to 1 000 ml of diluent (2 % volume fraction) to
improve solubility of gelatine (9.1.4.3 and 9.3).
6 Apparatus
Usual microbiological laboratory equipment for general use (see ISO 7218 and ISO 6887-1) and, in
particular, the following.
4 © ISO 2017 – All rights reserved

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SIST EN ISO 6887-4:2017
ISO 6887-4:2017(E)

6.1 Homogenizers.
6.1.1 Rotary homogenizer (blender).
Refer to ISO 7218. If a large sample is to be homogenized, the equipment should include a sterile 1 l bowl.
6.1.
...