SIST EN ISO 23319:2022
(Main)Cheese and processed cheese products, caseins and caseinates - Determination of fat content - Gravimetric method (ISO 23319:2022)
Cheese and processed cheese products, caseins and caseinates - Determination of fat content - Gravimetric method (ISO 23319:2022)
This document specifies a method for the determination of the fat content of all types of cheese and
processed cheese products containing lactose of below 5 % (mass fraction) of non-fat solids, and all
types of caseins and caseinates.
The method is not applicable to fresh cheese types containing, for example, fruits, syrup or muesli.
For such products, the Schmid-Bondzynski-Ratzlaff (SBR) principle is not applicable due to high
concentrations of sugars. For these products, the method using the Weibull-Berntrop principle (see
ISO 8262-3 | IDF 124-3[4]) is appropriate.
Käse und Schmelzkäseprodukte, Kaseine und Kaseinate - Bestimmung des Fettgehaltes - Gravimetrisches Verfahren (ISO 23319:2022)
Dieses Dokument legt ein Verfahren für die Bestimmung des Fettgehaltes aller Arten von Käse und Schmelz¬käse fest, deren Gehalt an Lactose weniger als 5 % (Massenanteil) der fettfreien Trockenmasse beträgt, und für alle Arten von Caseinen und Caseinaten.
Das Verfahren ist nicht auf Frischkäsearten anwendbar, die zum Beispiel Früchte, Sirup oder Müsli enthalten. Für derartige Produkte ist das Schmid-Bondzynski-Ratzlaff-Verfahren (SBR-Verfahren) aufgrund hoher Konzentratio¬nen von Zuckern nicht anwendbar. Für diese Produkte ist das Verfahren nach Weibull-Berntrop (siehe ISO 8262 3|IDF 124 3 [4]) geeignet.
WARNUNG — Die Anwendung dieses Dokuments kann gefährliche Substanzen, Arbeitsgänge und Geräte einschließen. Dieses Dokument erhebt nicht den Anspruch, dass alle mit seiner Anwendung verbundenen Sicherheitsprobleme angesprochen werden. Es liegt in der Verantwortung des An-wenders dieses Dokuments, Vorkehrungen für den Arbeits- und Gesundheitsschutz zu treffen und vor der Anwendung festzulegen, welche einschränkenden Vorschriften gelten.
Fromages et fromages fondus, caséines et caséinates - Détermination de la teneur en matière grasse - Méthode gravimétrique (ISO 23319:2022)
Le présent document spécifie une méthode de détermination de la teneur en matière grasse de tous les types de fromage et de fromage fondu ayant des teneurs en lactose inférieures à 5 % (fraction massique) des solides non gras, et de tous les types de caséines et caséinates.
La méthode n’est pas applicable aux fromages frais contenant, par exemple, des fruits, du sirop ou du muesli. Pour ces produits, le principe de Schmid-Bondzynski-Ratzlaff (SBR) n’est pas applicable en raison de fortes concentrations en sucres. Pour ces produits, la méthode utilisant le principe de Weibull-Berntrop (voir l’ISO 8262‑3 | IDF 124-3) est appropriée.
Siri in izdelki iz predelanih sirov, kazeini in kazeinati - Določevanje vsebnosti maščob - Gravimetrijska metoda (ISO 23319:2022)
Ta dokument določa metodo za določevanje vsebnosti maščob pri vseh vrstah sirov in izdelkov iz predelanih sirov z vsebnostjo laktoze pod 5 % (masnega deleža) v nemastni suhi snovi ter pri vseh vrstah kazeinov in kazeinatov. Metoda se ne uporablja za sveže sire, ki vsebujejo na primer sadje, sirup ali kosmiče. Načelo metode po Schmid-Bondzynski-Ratzlaffovu (SBR) pri takih izdelkih namreč ne velja, saj vsebujejo visoko koncentracijo sladkorjev. Za te izdelke je primerna metoda po načelu Weibull-Berntropa (glej standard ISO 8262-3 | IDF 124-3 [4]).
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 23319:2022
01-julij-2022
Nadomešča:
SIST EN ISO 1735:2005
Siri in izdelki iz predelanih sirov, kazeini in kazeinati - Določevanje vsebnosti
maščob - Gravimetrijska metoda (ISO 23319:2022)
Cheese and processed cheese products, caseins and caseinates - Determination of fat
content - Gravimetric method (ISO 23319:2022)
Käse und Schmelzkäseprodukte, Kaseine und Kaseinate - Bestimmung des Fettgehaltes
- Gravimetrisches Verfahren (ISO 23319:2022)
Fromages et fromages fondus, caséines et caséinates - Détermination de la teneur en
matière grasse - Méthode gravimétrique (ISO 23319:2022)
Ta slovenski standard je istoveten z: EN ISO 23319:2022
ICS:
67.100.30 Sir Cheese
SIST EN ISO 23319:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 23319:2022
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SIST EN ISO 23319:2022
EN ISO 23319
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2022
EUROPÄISCHE NORM
ICS 67.100.30 Supersedes EN ISO 1735:2004
English Version
Cheese and processed cheese products, caseins and
caseinates - Determination of fat content - Gravimetric
method (ISO 23319:2022)
Fromages et fromages fondus, caséines et caséinates - Käse und Schmelzkäseprodukte, Kaseine und
Détermination de la teneur en matière grasse - Kaseinate - Bestimmung des Fettgehaltes -
Méthode gravimétrique (ISO 23319:2022) Gravimetrisches Verfahren (ISO 23319:2022)
This European Standard was approved by CEN on 17 February 2022.
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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 23319:2022 E
worldwide for CEN national Members.
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SIST EN ISO 23319:2022
EN ISO 23319:2022 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 23319:2022
EN ISO 23319:2022 (E)
European foreword
This document (EN ISO 23319:2022) 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 October 2022, and conflicting national standards shall
be withdrawn at the latest by October 2022.
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 1735:2004.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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 23319:2022 has been approved by CEN as EN ISO 23319:2022 without any modification.
3
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SIST EN ISO 23319:2022
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SIST EN ISO 23319:2022
INTERNATIONAL ISO
STANDARD 23319
IDF 250
First edition
2022-03
Cheese and processed cheese
products, caseins and caseinates —
Determination of fat content —
Gravimetric method
Fromages et fromages fondus, caséines et caséinates —
Détermination de la teneur en matière grasse — Méthode
gravimétrique
Reference numbers
ISO 23319:2022(E)
IDF 250:2022(E)
© ISO and IDF 2022
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SIST EN ISO 23319:2022
ISO 23319:2022(E)
IDF 250:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO and IDF 2022
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: +41 22 749 01 11 Phone: +32 2 325 67 40
Fax: +32 2 325 67 41
Email: copyright@iso.org Email: info@fil-idf.org
Website: www.iso.org Website: www.fil-idf.org
Published in Switzerland
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SIST EN ISO 23319:2022
ISO 23319:2022(E)
IDF 250:2022(E)
Contents Page
Forewords .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 2
6 Apparatus . 2
7 Sampling . 4
8 Preparation of test sample . 4
8.1 Cheese . 4
8.2 Caseins and caseinates . 4
9 Procedure .5
9.1 Test portion . 5
9.2 Blank test . 5
9.3 Preparation of a fat-collecting vessel . 5
9.4 Determination . 5
10 Calculation and expression of results . 8
11 Precision . 9
11.1 Interlaboratory test . . 9
11.2 Repeatability . 9
11.3 Reproducibility . 9
11.4 Test report . 9
Annex A (informative) Additional procedures .11
Annex B (informative) Fat-extraction tube model with siphon or wash-bottle fittings .13
Annex C (informative) Interlaboratory test for cheeses .14
Annex D (informative) Interlaboratory test for caseins and caseinates .15
Bibliography .16
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SIST EN ISO 23319:2022
ISO 23319:2022(E)
IDF 250:2022(E)
Forewords
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 of the voluntary nature of standards, 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
www.iso.org/iso/foreword.html.
This document 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 the European
Committee for Standardization (CEN) Technical Committee CEN/TC 302, Milk and milk products -
Methods of sampling and analysis, in accordance with the Agreement on technical cooperation between
ISO and CEN (Vienna Agreement). It is being published jointly by ISO and IDF.
This first edition cancels and replaces ISO 1735 | IDF 5:2004 and ISO 5543 | IDF 127:2004, which have
been merged and technically revised.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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SIST EN ISO 23319:2022
ISO 23319:2022(E)
IDF 250:2022(E)
IDF (the International Dairy Federation) is a non-profit private sector organization representing the
interests of various stakeholders in dairying at the global level. IDF members are organized in National
Committees, which are national associations composed of representatives of dairy-related national
interest groups including dairy farmers, dairy processing industry, dairy suppliers, academics and
governments/food control authorities.
ISO and IDF collaborate closely on all matters of standardization relating to methods of analysis
and sampling for milk and milk products. Since 2001, ISO and IDF jointly publish their International
Standards using the logos and reference numbers of both organizations.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. IDF 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.
This document was prepared by the IDF Standing Committee on Analytical Methods for Composition
and ISO Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products,
in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/
TC 302, Milk and milk products - Methods of sampling and analysis, in accordance with the Agreement on
technical cooperation between ISO and CEN (Vienna Agreement). It is being published jointly by ISO
and IDF.
The work was carried out by the IDF/ISO Action Team (C34) of the Standing Committee on Analytical
Methods for Composition under the aegis of its project leader, Mr Philippe Trossat (FR).
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SIST EN ISO 23319:2022
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SIST EN ISO 23319:2022
ISO 23319:2022(E)
INTERNATIONAL STANDARD
IDF 250:2022(E)
Cheese and processed cheese products, caseins and
caseinates — Determination of fat content — Gravimetric
method
WARNING — The use of this document can involve hazardous materials, operations and
equipment. This document does not purport to address all the safety problems associated
with its use. It is the responsibility of the user of this document to establish safety and health
practices and to determine the applicability of regulatory limitations prior to use.
1 Scope
This document specifies a method for the determination of the fat content of all types of cheese and
processed cheese products containing lactose of below 5 % (mass fraction) of non-fat solids, and all
types of caseins and caseinates.
The method is not applicable to fresh cheese types containing, for example, fruits, syrup or muesli.
For such products, the Schmid-Bondzynski-Ratzlaff (SBR) principle is not applicable due to high
concentrations of sugars. For these products, the method using the Weibull-Berntrop principle (see
[4]
ISO 8262-3 | IDF 124-3 ) is appropriate.
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 565, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes
of openings
ISO 3889 | IDF 219, Milk and milk products — Specification of Mojonnier-type fat extraction flasks
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
fat content
mass fraction of substances determined by the procedure specified in this document
Note 1 to entry: The fat content is expressed as a percentage by mass.
4 Principle
A test portion is digested with hydrochloric acid, then ethanol is added. The acid-ethanolic solution
is subsequently extracted with diethyl ether and light petroleum. The solvents are removed by
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SIST EN ISO 23319:2022
ISO 23319:2022(E)
IDF 250:2022(E)
distillation or evaporation. The mass of the substances extracted, which are soluble in light petroleum,
is determined.
NOTE This is usually known as the Schmid-Bondzynski-Ratzlaff principle.
5 Reagents
Use only reagents of recognized analytical grade, unless otherwise specified, and distilled or
demineralized water or water of equivalent purity. The reagents shall leave no appreciable residue
when the determination is carried out by the method specified (see Annex A).
5.1 Concentrated hydrochloric acid, containing a mass fraction of HCl of approximately 36 %
(ρ = 1,18 g/ml).
20
5.2 Dilute hydrochloric acid, containing a mass fraction of approximately 25 % (ρ = 1,125 g/ml).
20
Dilute 675 ml of concentrated hydrochloric acid (5.1) to 1 000 ml with water and mix, or use dilute
hydrochloric acid if commercially available.
5.3 Ethanol, (C H OH), at least 94 % (volume fraction), or ethanol denatured by methanol, containing
2 5
a volume fraction of ethanol of at least 94 %, see A.5.
Ethanol denatured otherwise than by methanol may be used provided that the denaturant does not
affect the result of the determination (see A.5).
5.4 Diethyl ether (C H OC H ), free from peroxides (see A.3) and containing none or not more than
2 5 2 5
7 mg/kg of antioxidants (see A.4).
5.5 Light petroleum, with any boiling range between 30 °C and 60 °C or, as equivalent, pentane
[CH (CH ) CH ], with a boiling point of 36 °C.
3 2 3 3
5.6 Mixed solvent, prepared shortly before use by mixing equal volumes of diethyl ether (5.4) and
light petroleum (5.5).
6 Apparatus
Usual laboratory equipment and, in particular, the following.
6.1 Analytical balance, capable of weighing to the nearest 1 mg, with a readability of 0,1 mg.
6.2 Centrifuge, capable of holding the fat-extraction flasks or tubes (6.6 and 6.7) and capable of
producing a radial acceleration of around 80g to 90g at the outer end of the flasks or tubes.
NOTE The use of the centrifuge is optional but recommended (see 9.4.7).
6.3 Distillation or evaporation apparatus to enable the solvents and ethanol to be distilled from
the fat-collecting flasks or to be evaporated from beakers and dishes at a temperature not exceeding
100 °C.
6.4 Drying oven, electrically heated, with ventilation port(s) fully open, capable of being maintained
at a temperature of 102 °C ± 2 °C throughout the working space. Alternatively, a vacuum drying oven,
capable of being maintained at 72,5 °C ± 2,5 °C. A pressure less than 600 mbar (50 mmHg) may be used.
The drying oven shall be fitted with a suitable thermometer.
6.5 Boiling water bath or hot plate.
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SIST EN ISO 23319:2022
ISO 23319:2022(E)
IDF 250:2022(E)
6.6 Mojonnier-type fat-extraction flasks, as specified in ISO 3889 | IDF 219.
6.7 Extraction tubes-type fat-extraction flasks.
It is also possible to use fat-extraction tubes with siphon or wash-bottle fittings. For an example, see the
model in Figure B.1.
6.8 Stoppers.
The flasks or tubes (6.6 and 6.7) shall be provided with stoppers of different material, such as bark
cork, silicone rubber, polytetrafluoroethylene (PTFE) or glass, unaffected by the reagents used. Bark
corks shall be washed with the diethyl ether (5.4) and kept in water at 60 °C or more for at least 15 min.
They shall then be allowed to cool in the water so that they are saturated when used.
6.9 Rack, to hold the fat-extraction flasks or tubes.
6.10 Wash bottle, suitable for use with the mixed solvent (5.6). A plastic wash bottle shall not be used.
6.11 Fat-collecting vessels.
For example:
— boiling flasks, flat-bottomed, of capacity 125 ml to 250 ml;
— conical flasks, of capacity 250 ml;
— metal dishes.
If metal dishes are used, they shall preferably be of stainless steel, be flat-bottomed, and have a diameter
of 80 mm to 100 mm and a height of approximately 50 mm. Do not use aluminium dishes.
6.12 Boiling aids, fat-free, of non-porous porcelain or silicon carbide, or glass beads. The use of glass
beads is optional in the case of metal dishes.
6.13 Measuring cylinders or dispensers, of capacities 5 ml and 25 ml.
6.14 Pipette or dispenser, graduated, to deliver 10 ml.
6.15 Tongs, made of metal, capable of holding flasks, beakers or dishes.
6.16 Sheets of cellulose film, unlacquered, soluble in hydrochloric acid, of thickness 0,03 mm
to 0,05 mm, of dimensions 50 mm × 75 mm approximately. The sheets shall be inert under the test
conditions.
6.17 Grinding or grating device, for grinding or grating the laboratory sample if necessary. This
device should be such that no undue heat will be developed and no loss of moisture occurs. A hammer
mill shall not be used.
6.18 Test sieve, of woven wire cloth, diameter 200 mm, nominal size of opening 500 µm, with receiver,
conforming to the requirements of ISO 565.
6.19 Container with lid, airtight, of capacity such that the test sample can be mixed by shaking.
6.20 Beaker or flask, of capacity of 100 ml.
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SIST EN ISO 23319:2022
ISO 23319:2022(E)
IDF 250:2022(E)
7 Sampling
A representative sample should be sent to the laboratory. It should not be damaged or changed during
transport or storage.
Sampling is not part of the method specified in this document. A recommended sampling method is
[1]
given in ISO 707 | IDF 50 .
From the time of sampling to the time of commencing the procedure, the test samples shall be kept at
a temperature of between 2 °C and 6 °C for cheese and at room temperature for casein and caseinates.
8 Preparation of test sample
8.1 Cheese
Prior to analysis, remove the rind, the smear or the mouldy surface layer of the cheese in such a way as
to obtain a test sample representative of the cheese.
Grind or grate the test sample by using an appropriate grinding or grating device (6.17). Mix the ground
mass quickly and, if necessary for semi-hard and hard cheeses, grind it a second time and again mix
thoroughly.
For hard and semi-hard cheeses, previously to grind or grate, preferably cut into cubes of about
15 mm × 15 mm. Mix the cubes by shaking in a container and grind or grate the prepared sample as
specified before.
Clean the device after preparing each sample.
If the test sample cannot be ground or grated, mix it thoroughly by intensive kneading, for example
with a pestle in a mortar. Care should be taken to avoid moisture loss.
Store the test sample in an airtight container until commencing the analysis, which shall be carried out
as soon as possible after grinding.
If, however, a delay is unavoidable, take all precautions to ensure proper preservation of the test
sample. When refrigerated, bring the test sample to room temperature. Thoroughly mix the sample
to obviate the well-documented transfer of moisture within the cheese that occurs during cooling and
warming. Ensure that any condensation of moisture on the inside surface of the container is thoroughly
and uniformly re-incorporated into the test sample. Do not examine ground cheese showing unwanted
mould growth or signs of deterioration.
All sample preparation should be carried out in a manner which minimizes moisture loss. Such moisture
loss will have the effect of increasing the apparent fat content.
8.2 Caseins and caseinates
Thoroughly mix the laboratory sample, if necessary, after transferring all of it to an airtight container
of suitable capacity, by repeatedly shaking and inverting the container.
Transfer 50 g of the laboratory sample to the test sieve (6.18).
If it does not pass completely through the sieve, use the grinding device to achieve this condition.
Immediately transfer all the sieved sample to the container (6.19) and mix thoroughly in the closed
container. During these operations, take precautions to avoid any change in the water content of the
product.
If the 50 g portion directly passes through the sieve, or nearly completely passes, use this test sample
for the determination.
After the test sample has been prepared, proceed with the determination (see 9.4) as soon as possible.
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SIST EN ISO 23319:2022
ISO 23319:2022(E)
IDF 250:2022(E)
9 Procedure
9.1 Test portion
Mix the test sample by gently stirring. Immediately weigh, to the nearest 1 mg, directly or by difference,
1 g to 3 g of test sample for cheese and 2 g to 3 g for caseins and caseinates into a fat-extraction flask
(6.6 or 6.7), a 100 ml beaker or flask (6.20).
For cheeses having a mass fraction of fat of more than 30 %, adapt the mass of the test portion so as to
obtain a mass of extracted fat of between 750 mg and 1 000 mg.
The test portion may also be weighed on a sheet of cellulose film (6.16), which is subsequently folded and
introduced into the chosen vessel. For the Mojonnier type flask, deliver the test portion as completely
as possible into the lower (small) bulb of the fat-extraction flask.
9.2 Blank test
Carry out a blank test simultaneously with the determination, using the same procedure and same
reagents but omitting the test portion.
When a batch of test samples is analysed, the number of drying cycles may differ between different
samples. If one blank sample is used for the entire batch, ensure that the blank value, used in the
calculation of the fat content of any individual sample, was obtained under the same conditions as the
individual test sample.
If the value obtained in the blank test regularly exceeds 1,0 mg, check the reagents if this has not been
done recently (see A.1). Corrections for values of more than 2,5 mg in the blank test shall be reported in
the test report (see A.2).
9.3 Preparation of a fat-collecting vessel
Dry a fat-collecting vessel (6.11) with a few boiling aids (6.12) in the drying oven (6.4) for at least 1 h.
NOTE Boiling aids are desirable to promote gentle boiling during the subsequent removal
...
SLOVENSKI STANDARD
oSIST prEN ISO 23319:2020
01-september-2020
Sir in topljeni sir, kazeini in kazeinati - Določevanje maščob - Gravimetrijska
metoda (ISO/DIS 23319:2020)
Cheese and processed cheese products, caseins and caseinates - Determination of fat
content - Gravimetric method (ISO/DIS 23319:2020)
Fromages et fromages fondus, caséines et caséinates - Détermination de la teneur en
matière grasse - Méthode gravimétrique (ISO/DIS 23319:2020)
Ta slovenski standard je istoveten z: prEN ISO 23319
ICS:
67.100.30 Sir Cheese
oSIST prEN ISO 23319:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN ISO 23319:2020
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oSIST prEN ISO 23319:2020
DRAFT INTERNATIONAL STANDARD
ISO/DIS 23319
IDF 250
ISO/TC 34/SC 5 Secretariat: NEN
Voting begins on: Voting terminates on:
2020-03-26 2020-06-18
Cheese and processed cheese products, caseins
and caseinates — Determination of fat content —
Gravimetric method
ICS: 67.100.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference numbers
NATIONAL REGULATIONS.
ISO/DIS 23319:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
IDF 250:2020(E)
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO and IDF 2020
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oSIST prEN ISO 23319:2020
ISO/DIS 23319:2020(E)
IDF 250:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO and IDF 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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oSIST prEN ISO 23319:2020
ISO/DIS 23319:2020(E)
IDF 250:2020(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 2
6 Apparatus . 2
7 Sampling . 4
8 Preparation of test sample . 4
8.1 Cheese . 4
8.2 Caseins and caseinates . 4
9 Procedure. 5
9.1 Test portion . 5
9.2 Blank test . 5
9.3 Preparation of a fat-collecting vessel . 5
9.4 Determination . 5
10 Calculation and expression of results . 9
11 Precision . 9
11.1 Interlaboratory test. 9
11.2 Repeatability . 9
11.3 Reproducibility .10
11.4 Test report .10
Annex A (normative) Additional procedures .11
Annex B (normative) Fat extraction tube model with siphon or wash-bottle fittings .13
Annex C (normative) Interlaboratory test for cheeses .14
Annex D (normative) Interlaboratory test for caseins and caseinates .15
Bibliography .16
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oSIST prEN ISO 23319:2020
ISO/DIS 23319:2020(E)
IDF 250:2020(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 of the voluntary nature of standards, 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 www .iso .org/
iso/ foreword .html.
This document 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.
This first edition of ISO 23319 merges, cancels and replaces the following standards for the
determination of the fat content of milk and milk products using the SBR principle:
— ISO 1735:2004 | IDF 5:2004, Cheese and processed cheese products — Determination of fat content —
Gravimetric method (Reference method);
— ISO 5543:2004 | IDF 127:2004 Caseins and caseinates — Determination of fat content — Gravimetric
method (Reference method).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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oSIST prEN ISO 23319:2020
ISO/DIS 23319:2020(E)
IDF 250:2020(E)
IDF (the International Dairy Federation) is a non-profit private sector organization representing the
interests of various stakeholders in dairying at the global level. IDF members are organized in National
Committees, which are national associations composed of representatives of dairy-related national
interest groups including dairy farmers, dairy processing industry, dairy suppliers, academics and
governments/food control authorities.
ISO and IDF collaborate closely on all matters of standardization relating to methods of analysis
and sampling for milk and milk products. Since 2001, ISO and IDF jointly publish their International
Standards using the logos and reference numbers of both organizations.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. IDF 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.
This document was prepared by the IDF Standing Committee on Analytical Methods for Composition and
ISO Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is
being published jointly by ISO and IDF.
The work was carried out by the IDF/ISO Action Team (C34) of the Standing Committee on Analytical
Methods for Composition under the aegis of its project leader, Mr Philippe Trossat (FR).
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oSIST prEN ISO 23319:2020
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oSIST prEN ISO 23319:2020
ISO/DIS 23319:2020(E)
DRAFT INTERNATIONAL STANDARD
IDF 250:2020(E)
Cheese and processed cheese products, caseins
and caseinates — Determination of fat content —
Gravimetric method
WARNING — The use of this document may involve hazardous materials, operations and
equipment. This standard does not purport to address all the safety problems associated with
its use. It is the responsibility of the user of this standard to establish safety and health practices
and to determine the applicability of regulatory limitations prior to use.
1 Scope
This document specifies a method for the determination of the fat content of all types of cheese and
processed cheese products containing lactose of below 5 % (mass fraction) of non-fat solids, and all
types of caseins and caseinates.
The method is not applicable to fresh cheese type containing e.g. fruits, syrup or muesli. For such
products the Schmid–Bondzynski–Ratzlaff (SBR) principle is not applicable due to high concentrations
of sugars. For these products, the method using the Weibull-Berntrop principle (ISO 8262-3) is
appropriate.
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 3889, Milk and milk products — Specification of Mojonnier-type fat extraction flasks
ISO 565, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes
of openings
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
fat content
mass fraction of substances determined by the procedure specified in this document
Note 1 to entry: The fat content is expressed as a percentage by mass.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Principle
A test portion is digested with hydrochloric acid, then ethanol is added. The acid-ethanolic solution
is subsequently extracted with diethyl ether and light petroleum. The solvents are removed by
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oSIST prEN ISO 23319:2020
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IDF 250:2020(E)
distillation or evaporation. The mass of the substances extracted, which are soluble in light petroleum,
is determined.
NOTE This is usually known as the Schmid-Bondzynski-Ratzlaff principle.
5 Reagents
Use only reagents of recognized analytical grade, unless otherwise specified, and distilled or
demineralized water or water of equivalent purity. The reagents shall leave no appreciable residue
when the determination is carried out by the method specified (see Annex A).
5.1 Hydrochloric acid, containing a mass fraction of HCl of approximately 36 % (ρ20 = 1,18 g/ml)
5.2 Dilute hydrochloric acid, containing a mass fraction of approximately 25 % (ρ20 = 1,125 g/ml)
Dilute 675 ml of concentrated hydrochloric acid (5.2) to 1 000 ml with water and mix.
5.3 Ethanol, (C H OH), at least 94 % (volume fraction)
2 5
Ethanol denatured otherwise than by methanol may be used provided that the denaturant does not
affect the result of the determination (see A5).
5.4 Diethyl ether (C H OC H ), free from peroxides (see A3) and containing none or not more than
2 5 2 5
7 mg/kg of antioxidants (see A4)
5.5 Light petroleum, with any boiling range between 30°C and 60°C or, as equivalent, pentane
[CH (CH ) CH ], with a boiling point of 36 °C.
3 2 3 3
5.6 Mixed solvent, prepared shortly before use by mixing equal volumes of diethyl ether (5.4) and
light petroleum (5.5).
6 Apparatus
WARNING — Since the determination involves the use of volatile flammable solvents, all
electrical apparatus employed shall comply with legislation relating to the hazards in using
such solvents.
Usual laboratory equipment and, in particular, the following.
6.1 Analytical balance, capable of weighing to the nearest 1 mg, with a readability of 0,1 mg.
6.2 Centrifuge, capable of holding the fat-extraction flasks or tubes (6.6) and capable of spinning at a
-1 -1
rotational frequency of 500 min to 600 min to produce a radial acceleration of around 80 g to 90 g at
the outer end of the flasks or tubes.
NOTE The use of the centrifuge is optional but recommended (see 9.4.7).
6.3 Distillation or evaporation apparatus to enable the solvents and ethanol to be distilled from the
fat-collecting flasks or to be evaporated from beakers and dishes at a temperature not exceeding 100 °C.
6.4 Drying oven, electrically heated, with ventilation port(s) fully open, capable of being maintained
at a temperature of 102°C ± 2 °C throughout the working space, alternatively, a vacuum drying oven,
capable of being maintained at 72,5 ± 2,5 °C, and a pressure less than 600 mbar (50 mmHg) may be used.
The oven shall be fitted with a suitable thermometer.
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IDF 250:2020(E)
6.5 Boiling water bath or hot plate
6.6 Fat-extraction flasks
6.6.1 Mojonnier-type fat-extraction flasks, as specified in ISO 3889 | IDF 219
6.6.2 Extraction tubes-type fat extraction flask
It is also possible to use fat extraction tubes with siphon or wash-bottle fittings. For an example, see
model in Annex B.
6.6.3 Stoppers
The flasks or tubes shall be provided with stoppers of different material, such as bark cork, silicone
rubber, polytetrafluoroethylene (PTFE) or glass, unaffected by the reagents used. Bark corks shall be
washed with the diethyl ether (5.4), kept in water at 60 °C or more for at least 15 min, and shall then be
allowed to cool in the water so that they are saturated when used
6.7 Rack, to hold the fat-extraction flasks or tubes.
6.8 Wash bottle, suitable for use with the mixed solvent (5.6). A plastic wash bottle shall not be used.
6.9 Fat-collecting vessels
For example:
— boiling flasks, flat-bottomed, of capacity 125 ml to 250 ml;
— conical flasks, of capacity 250 ml;
— metal dishes.
If metal dishes are used, they shall preferably be of stainless steel, and shall be flat-bottomed, preferably
with a spout, and shall have a diameter of 80 mm to 100 mm and a height of approximately 50 mm. Do
not use aluminium dishes.
6.10 Boiling aids, fat-free, of non-porous porcelain or silicon carbide, or glass beads. The use of glass
beads is optional in the case of metal dishes.
6.11 Measuring cylinders of capacities 5 ml and 25 ml.
6.12 Pipettes, graduated, to deliver 10 ml.
6.13 Tongs, made of metal, capable of holding flasks, beakers or dishes.
6.14 Sheets of cellulose film, unlacquered, soluble in hydrochloric acid, of thickness of thickness 0,03
mm to 0,05 mm, of dimensions 50 mm × 75 mm approximately. The sheets shall be inert under the test
conditions.
6.15 Grinding or grating device, for grinding or grating the laboratory sample if necessary. This device
should be such that no undue heat will be developed and no loss of moisture occurs. A hammer mill shall
not be used.
6.16 Test sieve, of woven wire cloth, diameter 200 mm, nominal size of opening 500 µm, with receiver,
complying with the requirements of ISO 565.
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IDF 250:2020(E)
6.17 Container with lid, airtight, of capacity such that the test sample can be mixed by shaking.
6.18 Beaker of flask, of capacity of 100 ml.
7 Sampling
A representative sample should be sent to the laboratory. It should not be damaged or changed during
transport or storage. The laboratory sample shall be stored in a securely closed airtight container.
Sampling is not part of the method specified in this International Standard. A recommended sampling
[1]
method is given in ISO 707 .
From the time of sampling to the time of commencing the procedure, the test samples shall be kept at
a temperature of between 2 °C and 6 °C for cheese and at room temperature for casein and caseinates.
8 Preparation of test sample
8.1 Cheese
Prior to analysis, remove the rind, the smear or the mouldy surface layer of the cheese in such a way as
to obtain a test sample representative of the cheese.
Grind or grate the test sample by using an appropriate grinding or grating device (6.15). Mix the ground
mass quickly and, if necessary for semi-hard and hard cheeses, grind it a second time and again mix
thoroughly. Preferably, cut hard and semi-hard cheeses into cubes of about 15 mm × 15 mm. Mix the
cubes by shaking in a container. Grind or grate the test sample as specified before. Clean the device
after preparing each sample.
If the test sample cannot be ground or grated, mix it thoroughly by intensive kneading, for example
with a pestle in a mortar. Care should be taken to avoid moisture loss.
Store the test sample in an airtight container until commencing the analysis, which shall be carried out
as soon as possible after grinding.
If, however, a delay is unavoidable, take all precautions to ensure proper preservation of the test
sample. When refrigerated, bring the test sample to room temperature. Thoroughly mix the sample
to obviate the well-documented transfer of moisture within the cheese that occurs during cooling and
warming. Ensure that any condensation of moisture on the inside surface of the container is thoroughly
and uniformly re-incorporated into the test sample. Do not examine ground cheese showing unwanted
mould growth or signs of deterioration.
All sample preparation should be carried out in a manner which minimizes moisture loss. Such moisture
loss will have the effect of increasing the apparent fat content.
8.2 Caseins and caseinates
Thoroughly mix the laboratory sample, if necessary after transferring all of it to an airtight container of
suitable capacity, by repeatedly shaking and inverting the container.
Transfer 50 g of the laboratory sample to the test sieve (6.16). If it does not pass completely through the
sieve, use the grinding device to achieve this condition. Immediately transfer all the sieved sample to the
container (6.17) and mix thoroughly in the closed container. During these operations, take precautions
to avoid any change in the water content of the product.
After the test sample has been prepared, proceed with the determination (9.4) as soon as possible.
If the 50 g portion directly passes through the sieve, or nearly completely passes, use the prepared test
sample for the determination.
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oSIST prEN ISO 23319:2020
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IDF 250:2020(E)
9 Procedure
9.1 Test portion
Mix the test sample by gently stirring. Immediately weigh, to the nearest 1 mg, directly or by difference,
1 g to 3 g of test sample for cheese and 2 g to 3 g for caseins and caseinates into a fat-extraction flask
(6.6), a 100 ml beaker or flask (6.18).
For cheeses having a mass fraction of fat of more than 30 %, adapt the mass of the test portion so as to
obtain a mass of extracted fat of between 750 mg and 1 000 mg.
The test portion may also be weighed on a sheet of cellulose film (6.14), which is subsequently folded and
introduced into the chosen vessel. For the Mojonnier type flask, deliver the test portion as completely
as possible into the lower (small) bulb of the fat-extraction flask.
9.2 Blank test
Carry out a blank test simultaneously with the determination, using the same procedure and same
reagents but omitting the test portion.
When a batch of test samples is analysed, the number of drying cycles may differ between different
samples. If one blank sample is used for the entire batch, ensure that the blank value, used in the
calculation of the fat content of any individual sample, was obtained under the same conditions as the
individual test sample.
If the value obtained in the blank test regularly exceeds 1,0 mg, check the reagents if this has not been
done recently (see A.1). Corrections for values of more than 2,5 mg in the blank test shall be reported in
the test report (see A.2).
9.3 Preparation of a fat-collecting vessel
Dry a fat-collecting vessel (6.9) with a few boiling aids (6.10) in the drying oven (6.4) for 1 h.
NOTE Boiling aids are desirable to promote gentle boiling during the subsequent removal of solvent,
especially in the case of glass vessels; their use is optional in the case of metal dishes.
Allow the fat-collecting vessel to cool (protected from dust) to the temperature of the weighing room
(glass vessel for at least 1 h, metal dish for at least 30 min).
To avoid insufficient cooling or unduly long cooling times, the fat-collecting vessel should not be placed
in a desiccator.
Use tongs to place the fat-collecting vessel on the balance to avoid, in particular, temperature variations.
Weigh the dish to the nearest 1 mg.
9.4 Determination
9.4.1 Depending on the shape of the extraction apparatus and the size of the test portion, add 8 ml to
10 ml for cheese and 7.5 ml to 10 ml for caseins and caseinates of dilute hydrochloric acid (5.2). Add the
hydrochloric acid so as to wash the test portion and for Mojonnier type flask into the small bulb of the
fat-extraction flask (6.6) or onto the bottom of the beaker or flask (6.18), and mix.
9.4.2 Heat by gently moving the fat-extraction flask or vessel (to avoid charring) in a boiling water
bath or on a hot plate (6.5), until all particles are completely dissolved.
9.4.3 Allow the fat-extraction flask or vessel to stand for 20 min to 30 min in the boiling water bath
(6.5) or keep it gently boiling on the hot plate (6.5) for 10 min. Cool under running water.
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oSIST prEN ISO 23319:2020
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IDF 250:2020(E)
9.4.4 If the digestion has been carried out in the fat-extraction flask apparatus, add 10 ml of ethanol
(5.4). Mix gently but thoroughly by allowing the contents of the flask to flow backwards and forwards
and for Mojonnier type flask, between the two bulbs while not bringing the liquid too near to the neck.
Alternatively, if the digestion has been carried out in a vessel other than the fat-extraction flask (6.6),
pour the contents of the vessel into a fat-extraction flask (6.6). Rinse the vessel successively with 10
ml of ethanol (5.3). Mix gently as described above. Then rinse the vessel with 25 ml of diethyl ether
(5.4) and pour the vessel contents into the fat-extraction flask, while rinsing the tip or rim with some
additional diethyl ether or mixed solvent (5.6). Close the fat-extraction flask with a stopper (6.6.3) and
shake as described in 9.4.5. Finally rinse the vessel again with 25 ml of light petroleum (5.5) or mixed
solvent (5.6) and pour that solvent into the fat-extraction flask, while also rinsing the tip or rim with
some additional light petroleum. Close the fat-extraction flask again and shake its contents as described
in 9.4.6. Then continue with the centrifugation procedure as in 9.4.7.
9.4.5 Add 25 ml of diethyl ether (5.4). Close the fat-extraction flask with a stopper (6.6.3).
Shake the flask vigorously for 1 min, but not so vigorously as to cause formation of a persistent emulsion.
For Mojonnier type flask only, while shaking, keep the flask in a horizontal position with the small bulb
extending upwards, periodically allowing the liquid in the large bulb to run into the small bulb.
If necessary, cool the flask under running water.
Carefully remove stopper and rinse it and the neck of the flask with a little mixed solvent (5.6). Use the
wash bottle (6.8) so that the rinsings run into the fat-extraction flask.
9.4.6 Add 25 ml of the light petroleum (5.5). Close the fat-extraction flask with the stopper.
Gently shake the flask as described in 9.4.5, but for 30 s only.
-1 -1
9.4.7 Centrifuge the closed fat-extraction flask at a rotational frequency of 500 min to 600 min for 1
min to 5 min. If a centrifuge is
...
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