EN ISO 660:2009
(Main)Animal and vegetable fats and oils - Determination of acid value and acidity (ISO 660:2009)
Animal and vegetable fats and oils - Determination of acid value and acidity (ISO 660:2009)
ISO 660:2009 specifies three methods (two titrimetric and one potentiometric) for the determination of the acidity in animal and vegetable fats and oils. The acidity is expressed preferably as acid value, or alternatively as acidity calculated conventionally.
ISO 660:2009 is applicable to refined and crude vegetable or animal fats and oils, soap stock fatty acids or technical fatty acids. The methods are not applicable to waxes.
Since the methods are completely non-specific, they cannot be used to differentiate between mineral acids, free fatty acids, and other organic acids. The acid value, therefore, also includes any mineral acids that may be present.
Tierische und pflanzliche Fette und Öle - Bestimmung der Säurezahl und der Azidität (ISO 660:2009)
Diese Internationale Norm legt drei Verfahren (zwei titrimetrische und ein potentiometrisches) zur Bestimmung der Azidität in tierischen und pflanzlichen Fetten und Ölen, die im Folgenden als Fette bezeichnet werden, fest. Die Azidität wird vorzugsweise als Säurezahl ausgedrückt, alternativ als konventionell berechnete Azidität.
Die Norm gilt für raffinierte und rohe pflanzliche oder tierische Fette und Öle, Soapstock Fettsäuren oder technische Fettsäuren. Die Verfahren gelten nicht für Wachse.
Da die Verfahren vollkommen unspezifisch sind, können diese zur Unterscheidung zwischen Mineralsäuren, freien Fettsäuren und sonstigen organischen Säuren nicht angewendet werden. Die Säurezahl umfasst daher auch möglicherweise vorhandene Mineralsäuren.
Corps gras d'origines animale et végétale - Détermination de l'indice d'acide et de l'acidité (ISO 660:2009)
L'ISO 660:2009 spécifie trois méthodes (deux titrimétriques et une potentiométrique) pour la détermination de l'acidité dans les corps gras d'origines animale et végétale dits corps gras. L'acidité est exprimée, de préférence, en indice d'acide ou bien en acidité calculée conventionnellement.
L'ISO 660:2009 est applicable aux corps gras d'origines végétale ou animale à l'état brut ou raffinés, aux acides gras des pâtes de neutralisation ou aux acides gras de qualité technique. Ces méthodes ne sont pas applicables aux cires.
Ces méthodes ne sont en aucun cas spécifiques, elles ne peuvent donc pas être utilisées pour différencier les acides minéraux, les acides gras libres et autres acides organiques. De ce fait, l'indice d'acide inclut tout acide minéral potentiellement présent.
Rastlinske in živalske maščobe in olja - Določevanje kislinskega števila in kislosti (ISO 660:2009)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2009
1DGRPHãþD
SIST EN ISO 660:2000
SIST EN ISO 660:2000/A1:2005
5DVWOLQVNHLQåLYDOVNHPDãþREHLQROMD'RORþHYDQMHNLVOLQVNHJDãWHYLODLQNLVORVWL
,62
Animal and vegetable fats and oils - Determination of acid value and acidity (ISO
660:2009)
Tierische und pflanzliche Fette und Öle - Bestimmung der Säurezahl und der Azidität
(ISO 660:2009)
Corps gras d'origines animale et végétale - Détermination de l'indice d'acide et de
l'acidité (ISO 660:2009)
Ta slovenski standard je istoveten z: EN ISO 660:2009
ICS:
67.200.10 5DVWOLQVNHLQåLYDOVNH Animal and vegetable fats
PDãþREHLQROMD and oils
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN ISO 660
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2009
ICS 67.200.10 Supersedes EN ISO 660:1999
English Version
Animal and vegetable fats and oils - Determination of acid value
and acidity (ISO 660:2009)
Corps gras d'origines animale et végétale - Détermination Tierische und pflanzliche Fette und Öle - Bestimmung der
de l'indice d'acide et de l'acidité (ISO 660:2009) Säurezahl und der Azidität (ISO 660:2009)
This European Standard was approved by CEN on 20 May 2009.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 660:2009: E
worldwide for CEN national Members.
Contents Page
Foreword .3
Foreword
This document (EN ISO 660:2009) has been prepared by Technical Committee ISO/TC 34 "Food products" in
collaboration with Technical Committee CEN/TC 307 "Oilseeds, vegetable and animal fats and oils and their
by-products - Methods of sampling and analysis", the secretariat of which is held by AFNOR.
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 December 2009, and conflicting national standards shall be withdrawn
at the latest by December 2009.
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 660:1999.
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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 660:2009 has been approved by CEN as a EN ISO 660:2009 without any modification.
INTERNATIONAL ISO
STANDARD 660
Third edition
2009-06-15
Animal and vegetable fats and oils —
Determination of acid value and acidity
Corps gras d'origines animale et végétale — Détermination de l'indice
d'acide et de l'acidité
Reference number
ISO 660:2009(E)
©
ISO 2009
ISO 660:2009(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2009 – All rights reserved
ISO 660:2009(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 660 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 11, Animal and
vegetable fats and oils.
This third edition cancels and replaces the second edition (ISO 660:1996), which has been technically revised.
It also incorporates the Amendment ISO 660:1996/Amd.1:2003.
INTERNATIONAL STANDARD ISO 660:2009(E)
Animal and vegetable fats and oils — Determination of acid
value and acidity
1 Scope
This International Standard specifies three methods (two titrimetric and one potentiometric) for the
determination of the acidity in animal and vegetable fats and oils, hereinafter referred to as fats. The acidity is
expressed preferably as acid value, or alternatively as acidity calculated conventionally.
This International Standard is applicable to refined and crude vegetable or animal fats and oils, soap stock
fatty acids or technical fatty acids. The methods are not applicable to waxes.
Since the methods are completely non-specific, they cannot be used to differentiate between mineral acids,
free fatty acids, and other organic acids. The acid value, therefore, also includes any mineral acids that may
be present.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document applies.
ISO 661, Animal and vegetable fats and oils — Preparation of test sample
ISO 3696, Water for analytical laboratory use — Specification and test methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
acid value
number of milligrams of potassium hydroxide required to neutralize the free fatty acids present in 1 g of fat,
when determined in accordance with the procedure specified in this International Standard
NOTE The acid value is expressed in milligrams per gram.
3.2
acidity
content of free fatty acids determined according to the procedure specified in this International Standard
NOTE The acidity is expressed as a percentage by mass. If the result of the determination is reported as acidity
without further explanation, this is, by convention, the acidity based on the oleic acid content.
ISO 660:2009(E)
4 Principle
The sample is dissolved in a suitable solvent mixture, and the acids present are titrated with an ethanolic or
methanolic solution of potassium or sodium hydroxide.
The methods specified in 9.1 and 9.2 are reference methods.
5 Reagents
WARNING — Attention is drawn to the regulations which specify the handling of hazardous
substances. Technical, organizational and personal safety measures shall be followed.
Use only reagents of recognized analytical grade, unless otherwise specified.
5.1 Solvent A for solvent mixture (5.3): ethanol, volume fraction, ϕ ≈ 96 %.
As a replacement, propan-2-ol, volume fraction, ϕ ≈ 99 %, can be used.
5.2 Solvent B for solvent mixture (5.3): diethyl ether, peroxide-free.
As a replacement, tert-butyl methyl ether, light petroleum (boiling range 40 °C to 60 °C) or toluene can be
used.
WARNING — Diethyl ether is very flammable and may form explosive peroxides. Use with great
caution.
5.3 Solvent mixture, mix equal volumes of solvent A and B, (e.g. ϕ = 50 ml/100 ml and
A
ϕ = 50 ml/100 ml).
B
For hard or animal fats, a solvent mixture of one volume of solvent A (e.g. 25 ml) and three volumes of tert-
butyl methyl ether or toluene (e.g. 75 ml) is recommended.
Neutralize, just before use, by adding potassium hydroxide solution in the presence of 0,3 ml of the
phenolphthalein solution per 100 ml of solvent mixture.
For the titration with aqueous KOH, the solvent propan-2-ol can be used.
5.4 Ethanol or methanol, of minimum volume fraction, ϕ = 95 %.
5.5 Sodium hydroxide or potassium hydroxide, ethanolic or methanolic standard volumetric solutions,
amount of substance concentration c(NaOH) or c(KOH) = 0,1 mol/l and 0,5 mol/l. The concentration shall be
checked with a standard volumetric HCl solution.
NOTE The ethanolic/methanolic sodium/potassium hydroxide solution may be replaced by an aqueous
sodium/potassium hydroxide solution, but only if the volume of water introduced does not lead to phase separation.
5.6 Phenolphthalein, solution in ethanol, mass concentration, ρ = 1 g/100 ml.
5.7 Thymolphthalein, solution in ethanol, mass concentration, ρ = 2 g/100 ml.
5.8 Alkali blue 6B, solution in ethanol, mass concentration, ρ = 2 g/100 ml.
For dark-coloured fats, alkali blue or thymolphthalein shall be used.
5.9 Water in accordance with ISO 3696, grade 3.
2 © ISO 2009 – All rights reserved
ISO 660:2009(E)
6 Apparatus
Usual laboratory equipment and, in particular, the following.
[1]
6.1 Burette, capacity 10 ml, graduated in 0,02 ml, ISO 385 class A.
[1]
6.2 Burette, capacity 25 ml, graduated in 0,05 ml, ISO 385 class A.
6.3 Analytical balance, capable of being read to the nearest 0,001 g.
6.4 Automatic titration apparatus (based on potentiometric electrode) or potentiometer.
6.5 Combined pH electrode for non-aqueous acid/base titrations.
[2]
6.6 Graduated volumetric flasks, volume 1 000 ml, ISO 1042 class A.
7 Sampling
A representative sample should have been sent to the laboratory. It should not have been damaged or
changed during transport or storage.
Sampling is not part of the method specified in this International Standard. A recommended sampling method
[3]
is given in ISO 5555 .
8 Preparation of test sample
Prepare the test sample in accordance with ISO 661, except that if the sample contains volatile fatty acids, the
test sample shall not be heated and filtered.
9 Procedure
9.1 Cold solvent method using indicator (Reference method)
9.1.1 Depending on the expected magnitude of the acid value, select the test portion mass and alkali
concentration from Table 1.
9.1.2 According to Table 1 weigh the test portion into a 250 ml conical flask.
9.1.3 Add 50 ml to 100 ml of the neutralized solvent mixture (5.3) and dissolve the test portion if necessary
with gentle warming.
For high melting point samples, use an ethanol-toluene mixture.
9.1.4 After the addition of an indicator (5.6, 5.7 or 5.8), titrate with constant swirling using standard
potassium hydroxide solution (5.5). The endpoint of the titration is reached when the addition of a single drop
of alkali produces a slight but definite colour change persisting for at least 15 s.
ISO 660:2009(E)
Table 1 —
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.