EN ISO 27107:2008
(Main)Animal and vegetable fats and oils - Determination of peroxide value - Potentiometric end-point determination (ISO 27107:2008)
Animal and vegetable fats and oils - Determination of peroxide value - Potentiometric end-point determination (ISO 27107:2008)
This European Standard specifies a method for the determination of the peroxide value of animal and vegetable fats and oils. The method is applicable to all animal and vegetable fats and oils, fatty acids and their mixtures with peroxide values from 0 milliequivalents (meq) to 30 meq of active oxygen per kg. It is also applicable to margarines and fat spreads with varying water content. The method should not be used for milk fats; the method specified in ISO 3976:2006 is preferred. Also, the method is not applicable to lecithins. It is to be noted that the peroxide value is a dynamic value, whose value is dependent upon the history of the sample. Furthermore, the determination of the peroxide value is a highly empirical procedure and the value obtained depends on the sample mass. The user of this International Standard should be aware that due to the prescribed sample mass, the peroxide values obtained can be slightly lower than those obtained with lower sample mass. For some products, the amount of extracted fat/oil can be lower than 5 g, or the peroxide value of the fat/oil can be over 30 meq active oxygen per kg. In these cases, the user should choose a smaller sample mass. As the sample mass influences the result, this should be reported together with the result.
Tierische und pflanzliche Fette und Öle - Bestimmung der Peroxidzahl - Potentiometrische Endpunktbestimmung (ISO 27107:2008)
Die vorliegende Internationale Norm legt ein Verfahren zur potentiometrischen Endpunktbestimmung der Peroxidzahl, in Milliäquivalent aktiver Sauerstoff je Kilogramm, von tierischen und pflanzlichen Fetten und Ölen fest.
Das Verfahren ist auf alle tierischen und pflanzlichen Fette und Öle, Fettsäuren und deren Mischungen mit Peroxidzahlen von 0 meq bis 30 meq aktiver Sauerstoff je Kilogramm anwendbar. Es ist auch anwendbar auf Margarinen und Streichfette mit unterschiedlichem Wassergehalt. Das Verfahren ist nicht anwendbar auf Milch¬fette oder Lecithine.
ANMERKUNG Ein Verfahren zur iodometrischen (visuellen) Bestimmung der Peroxidzahl ist in ISO 3960 angeführt. Ein Verfahren für Milchfette ist in ISO 3976 festgelegt.
Corps gras d'origines animale et végétale - Détermination de l'indice de peroxyde - Détermination avec point d'arrêt potentiométrique (ISO 27107:2008)
Rastlinske in živalske maščobe in olja - Določevanje peroksidnega števila - Potenciometrijsko določanje končne točke (ISO 27107:2008)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2009
5DVWOLQVNHLQåLYDOVNHPDãþREHLQROMD'RORþHYDQMHSHURNVLGQHJDãWHYLOD
3RWHQFLRPHWULMVNRGRORþDQMHNRQþQHWRþNH ,62
Animal and vegetable fats and oils - Determination of peroxide value - Potentiometric
end-point determination (ISO 27107:2008)
Tierische und pflanzliche Fette und Öle - Bestimmung der Peroxidzahl -
Potentiometrische Endpunktbestimmung (ISO 27107:2008)
Corps gras d'origines animale et végétale - Détermination de l'indice de peroxyde -
Détermination avec point d'arrêt potentiométrique (ISO 27107:2008)
Ta slovenski standard je istoveten z: EN ISO 27107:2008
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 27107
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2008
ICS 67.200.10
English Version
Animal and vegetable fats and oils - Determination of peroxide
value - Potentiometric end-point determination (ISO
27107:2008)
Corps gras d'origines animale et végétale - Détermination Tierische und pflanzliche Fette und Öle - Bestimmung der
de l'indice de peroxyde - Détermination avec point d'arrêt Peroxidzahl - Potentiometrische Endpunktbestimmung (ISO
potentiométrique (ISO 27107:2008) 27107:2008)
This European Standard was approved by CEN on 23 October 2008.
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: rue de Stassart, 36 B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 27107:2008: E
worldwide for CEN national Members.
Contents Page
Foreword.3
Foreword
The text of ISO 27107:2008 has been prepared by Technical Committee ISO/TC 34 “Agricultural food
products” of the International Organization for Standardization (ISO) and has been taken over as EN ISO
27107:2008 by 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 May 2009, and conflicting national standards shall be withdrawn at the
latest by May 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.
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 27107:2008 has been approved by CEN as a EN ISO 27107:2008 without any modification.
INTERNATIONAL ISO
STANDARD 27107
First edition
2008-03-01
Animal and vegetable fats and oils —
Determination of peroxide value —
Potentiometric end-point determination
Corps gras d'origines animale et végétale — Détermination de l'indice
de peroxyde — Détermination avec point d'arrêt potentiométrique
Reference number
ISO 27107:2008(E)
©
ISO 2008
ISO 27107:2008(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 2008
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 2008 – All rights reserved
ISO 27107:2008(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 27107 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 11, Animal
and vegetable fats and oils.
ISO 27107:2008(E)
Introduction
Over many years, various methods have been developed for the determination of peroxides in fats and oils.
Their general principle is the liberation of iodine from potassium iodide in an acid medium. The method
according to Wheeler (Reference [6]) was first adopted in standards more than 50 years ago by different
bodies, and is widely used to control commodities by producers, receivers, and official laboratories. In national
and international food legislation (including Codex Alimentarius), acceptable limits for peroxide values are
often specified. Due to anomalies in the reproducibility of the results, it was noticed that there are slight
differences between the standardized methods. A very important point is the dependence of the result on the
amount of sample used for the determination. As the determination of the peroxide value (PV) is a highly
empirical procedure, ISO/TC 34/SC 11 has decided to fix the sample mass at 5 g for PV > 1, and at 10 g for
PV u 1, and to limit the applicability of this method to animal and vegetable fats and oils with peroxide values
from 0 mmol to 15 mmol of active oxygen per kilogram. The users of this International Standard should be
aware that the results obtained can be slightly lower than with previous standards.
iv © ISO 2008 – All rights reserved
INTERNATIONAL STANDARD ISO 27107:2008(E)
Animal and vegetable fats and oils — Determination of peroxide
value — Potentiometric end-point determination
1 Scope
This International Standard specifies a method for the potentiometric end-point determination of the peroxide
value, in milliequivalents of active oxygen per kilogram, of animal and vegetable fats and oils.
The method is applicable to all animal and vegetable fats and oils, fatty acids and their mixtures with peroxide
values from 0 meq to 30 meq of active oxygen per kilogram. It is also applicable to margarines and fat
spreads with varying water content. The method is not applicable to milk fats or lecithins.
NOTE A method for the iodometric (visual) determination of the peroxide value is given in ISO 3960. For milk fats, a
method is specified in ISO 3976.
2 Normative references
The following referenced documents are indispensable for the application of this document. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 661, Animal and vegetable fats and oils — Preparation of test sample
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
peroxide value
PV
quantity of those substances in the sample, expressed in terms of active oxygen, that oxidize potassium
iodide under the conditions specified in this International Standard
NOTE The peroxide value is usually expressed in milliequivalents of active oxygen per kilogram of oil, but it may also
be expressed (in SI units) as millimoles of active oxygen per kilogram of oil. The value expressed in millimoles of active
oxygen per kilogram is half that expressed in milliequivalents of active oxygen per kilogram. Multiplication of the peroxide
value (milliequivalents of active oxygen per kilogram) by the equivalent mass of oxygen (equalling 8) gives the active
oxygen mass fraction in milligrams per kilogram of oil.
4 Principle
The sample is dissolved in isooctane and glacial acetic acid, and potassium iodide is added. The iodide
liberated by the peroxides is determined volumetrically with a sodium thiosulfate standard solution. The
end-point of the titration is determined electrochemically.
ISO 27107:2008(E)
5 Reagents
WARNING — Attention is drawn to national regulations that specify the handling of hazardous
substances, and users' obligations thereunder. Technical, organizational and personal safety
measures shall be followed.
Unless otherwise specified, use only reagents of recognized analytical grade. All reagents shall be free of
dissolved oxygen.
5.1 Water, distilled, boiled, and cooled to 20 °C.
5.2 Glacial acetic acid, mass fraction 100 %, degassed in an ultrasonic bath under vacuum or by purging
with a stream of pure and dry inert gas (carbon dioxide or nitrogen).
5.3 Isooctane (2,2,4-trimethylpentane), degassed in an ultrasonic bath under vacuum or by purging with a
stream of pure and dry inert gas (carbon dioxide or nitrogen).
5.4 Glacial acetic acid/isooctane solution, prepared by mixing 60 ml glacial acetic acid (5.2) and 40 ml
isooctane (5.3). Volume fraction of glacial acetic acid: ϕ = 60 ml/100 ml; volume fraction of isooctane:
ϕ = 40 ml/100 ml.
The mixture is degassed in an ultrasonic bath under vacuum or by purging with a stream of pure and dry inert
gas (carbon dioxide or nitrogen).
5.5 Potassium iodide, free from iodine and iodates.
5.6 Saturated potassium iodide solution, mass concentration ρ(KI) = 175 g/100 ml.
Dissolve approximately 14 g potassium iodide in approximately 8 g freshly boiled water (5.1) at room
temperature. Make sure the solution remains saturated (i.e. some undissolved crystals remain in the
container). Store in the dark and prepare freshly every day. Test the solution as follows: add two drops of
starch solution to 0,5 ml of the potassium iodide solution in 30 ml of the glacial acetic acid/isooctane solution
(5.4). If more than one drop of sodium thiosulfate standard solution (5.7) is needed to form a blue colour,
discard the potassium iodide solution.
5.7 0,1 N sodium thiosulfate standard solution, amount of substance concentration
c(Na S O ) = 0,1 mol/l.
2 2 3
Use only freshly boiled water (5.1) for the preparation of this solution, possibly purged with nitrogen. This
solution can be used for 1 month and shall be stored in an amber-stained bottle.
5.8 0,01 N sodium thiosulfate standard solution, amount of substance concentration
c(Na S O ) = 0,01 mol/l.
2 2 3
Pipette (6.3) 100 ml of the 0,1 N sodium thiosulfate standard solution (5.7) into a volumetric flask of capacity
1 000 ml (6.9). Make up to the mark with water (5.1). After homogenization, transfer the obtained 0,01 N
sodium thiosulfate standard solution to an amber-stained bottle.
Prepare the 0,01 N sodium thiosulfate standard solution freshly from the 0,1 N
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.