SIST ISO 660:1995
(Main)Animal and vegetable fats and oils -- Determination of acid value and of acidity
Animal and vegetable fats and oils -- Determination of acid value and of acidity
Corps gras d'origines animale et végétale -- Détermination de l'indice d'acide et de l'acidité
Rastlinske in živalske maščobe in olja - Določanje kislinskega števila in kislosti
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International Standard @ 660
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION.ME)((I1YHAPOLIHAR OPrAHH3AUHR no CTAHAAPTH3AUHH.ORGANlSATlON INTERNATIONALE DE NORMALISATION
Animal and vegetable fats and oils - Determination of
- acid value and of acidity
Corps gras d'origines animale et végétale - Détermination de l'indice d'acide et de i'acidité
First edition - 1983-11-01
UDC 664.3 : 543.852.1 Ref. No. IS0 660-1983 (E)
c
-
8 Descriptors : animal fats, vegetable fats, vegetable oils, tests, determination, acidity, acid number.
rn
-
Price based on 4 pages
---------------------- Page: 1 ----------------------
Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of
national standards bodies (IS0 member bodies). The work of developing International
Standards is carried out through IS0 technical committees. Every member body
interested in a subject for which a technical committee has been authorized 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.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council.
International Standard IS0 660 was developed by Technical Committee ISO/TC 34,
Agricultural food products, and was circulated to the member bodies in
September 1982.
It has been approved by the member bodies of the following countries :
Australia
Iran Poland
Austria
Iraq Portugal
Bulgaria South Africa, Rep. of
Israel
Canada
Italy Spain
Egypt, Arab Rep. of Tanzania
Kenya
Ethiopia
Korea, Dem. P. Rep. of Thailand
France Mexico United Kingdom
Germany, F. R. USA
Malaysia
Hungary New Zealand USSR
India Philippines Yugoslavia .
The member body of the following country expressed disapproval of the document on
technical grounds :
Netherlands
This International Standard cancels and replaces IS0 Recommendation R 660-1968. of
which it constitutes a technical revision.
@ International Organization for Standardization, 1983 O
Printed in Switzerland
---------------------- Page: 2 ----------------------
INTERNATIONAL STANDARD IS0 660-1983 (E)
Animal and vegetable fats and oils - Determination of
acid value and of acidity
Scope and field of application If the result is reported simply as "acidity", without further
1
definition, this is, by convention, the acidity expressed as oleic
This International Standard specifies two methods (titrimetric acid.
and potentiometric) for the determination of free fatty acids in
L.
animal and vegetable fats and oils. The acids are expressed If the sample contains mineral acids, these are, by convention,
preferably as the acid value or alternatively as acidity calculated determined as fatty acids.
conventionally.
4 Titrirnetric method
The method is applicable to animal and vegetable fats and oils.
It is not applicable to waxes.
4.1 General
This method is most suitable for fats and oils which are not
2 References
strongly coloured.
IS0 661, Animal and vegetable fats and oils - Preparation of
test sample.
4.2 Principle
IS0 5555, Animal and vegetable fats and oils - Sampling.
Dissolution of a test portion in a mixed solvent, followed by
titration of the free fatty acids present with ethanolic potassium
hydroxide solution.
3 Definitions
4.3 Reagents
For the purpose of this International Standard, the following
definitions apply.
All the reagents shall be of recognized analytical quality and the
water used shall be distilled water or water of equivalent purity.
3.1 acid value : Number of milligrams of potassium
hydroxide required to neutralize the free fatty acids in 1 g of fat
4.3.1 Diethyl ether/% % (V/V ethanol, 1 + 1 (V/V
or oil.
mixture.
3.2 acidity : Conventional expression of the percentage free
WARNING - Diethyl ether is very flammable and may
fatty acids.
It shall be used with great
form explosive peroxides.
caution.
According to the nature of the fat or oil, it can be expressed as
indicated in table 1.
Neutralize exactly, just before use, by adding the potassium
hydroxide solution (4.3.2) in the presence of 0,3 ml of the
phenolphthalein solution (4.3.3) per 100 ml of mixture.
Table 1
Molar
NOTE - If it is not possible to use diethyl ether, a mixed solvent of
Expressed as mass
Nature of fat or oil
ethanol and toluene can be used. If necessary, ethanol may be
g/mol
I
replaced by propan-2-01.
Coconut oil, palm kernel oil Lauric acid 200
and similar oils
4.3.2 Potassium hydroxide, ethanolic standard volumetric
Palm oil Palmitic acid 256 solution, c(K0H) = 0,l mol/l, or, if necessary,
c(KOH) = 0.5 mol/l.
=a
Oils from certain cruciferae' Erucic acid
Oleic acid
All other fats and oils 282
The exact concentration of the ethanolic potassium hydroxide
'
solution shall be known, and shall be checked immediately
In the case of rapeseed oil having low erucic acid contents, the
acidity shall be expressed as oleic acid. before use. Use a solution prepared at least 5 days before and
1
---------------------- Page: 3 ----------------------
IS0 660-1983 (E)
4.6.3 Determination
decanted into a brown glass bottle, fitted with a rubber
stopper. The solution shall be colourless or straw yellow.
test portion (4.6.2) in 50 to 150 ml of the pre-
Dissolve the
viously neutralized diethyl ether/ethanol mixture (4.3.1).
NOTE - A stable colourless solution of potassium hydroxide can be
prepared in the following manner. Boil under reflux 1 O00 ml of ethanol
with 8 g of potassium hydroxide and 0.5 g of aluminium pellets for 1 h,
Titrate, whilst swirling the solution, with the 0,l mol/l
then distil immediately. Dissolve the required amount of potassium
potassium hydroxide solution (4.3.2) (see note 3) to the end
hydroxide in the distillate. Allow the whole to stand for several days
of
point as indicated by the indicator (pink colour
and decant the clear supernatant liquid from the deposited potassium
phenolphthalein persisting for at least 10 SI.
carbonate.
The solution can also be prepared without distillation in the following
NOTES
1 O00 ml of ethanol and
manner. Add 4 ml of aluminium butylate to
1 In the case of very low acid values i < 1). it is preferable to pass a
allow the mixture to stand for several days. Decant the supernatant
gentle flow of nitrogen through the test solution.
liquid and dissolve in it the required amount of potassium hydroxide.
This solution is ready for use.
2 The ethanolic standard volumetric potassium hydroxide solution
or sodium hydroxide
(4.3.2) can be replaced by an aqueous potassium
solution when the volume of water introduced does not lead to phase
4.3.3 Phenolphthalein, 10 g/l solution in 95 to 96 % ( V/ V)
-
separation.
ethanol, or alkali blue (in the case of strongly coloured
3 If the quantity of 0,l mol/l potassium hydroxide solution required
samples), 20 g/l solution in 95 to 96 % ( V/ V) ethanol.
exceeds 10 mi, use the 0.5 mol/l solution.
4 If the solution becomes turbid during titration, add a sufficient
4.4 Apparatus
quantity of the mixed solvent (4.3.1) to give a clear solution.
Usual laboratory equipment, and in particular
4.6.4 Number of determinations
4.4.1 Analytical balance.
Carry out two determinations on the same test sample.
4.4.2 Conical flask, of capacity 250 ml.
5 Potentiometric method
4.4.3 Burette,
...
SLOVENSKI STANDARD
SIST ISO 660:1995
01-december-1995
5DVWOLQVNHLQåLYDOVNHPDãþREHLQROMD'RORþDQMHNLVOLQVNHJDãWHYLODLQNLVORVWL
Animal and vegetable fats and oils -- Determination of acid value and of acidity
Corps gras d'origines animale et végétale -- Détermination de l'indice d'acide et de
l'acidité
Ta slovenski standard je istoveten z: ISO 660:1983
ICS:
67.200.10 5DVWOLQVNHLQåLYDOVNH Animal and vegetable fats
PDãþREHLQROMD and oils
SIST ISO 660:1995 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST ISO 660:1995
---------------------- Page: 2 ----------------------
SIST ISO 660:1995
International Standard @ 660
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION.ME)((I1YHAPOLIHAR OPrAHH3AUHR no CTAHAAPTH3AUHH.ORGANlSATlON INTERNATIONALE DE NORMALISATION
Animal and vegetable fats and oils - Determination of
- acid value and of acidity
Corps gras d'origines animale et végétale - Détermination de l'indice d'acide et de i'acidité
First edition - 1983-11-01
UDC 664.3 : 543.852.1 Ref. No. IS0 660-1983 (E)
c
-
8 Descriptors : animal fats, vegetable fats, vegetable oils, tests, determination, acidity, acid number.
rn
-
Price based on 4 pages
---------------------- Page: 3 ----------------------
SIST ISO 660:1995
Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of
national standards bodies (IS0 member bodies). The work of developing International
Standards is carried out through IS0 technical committees. Every member body
interested in a subject for which a technical committee has been authorized 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.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council.
International Standard IS0 660 was developed by Technical Committee ISO/TC 34,
Agricultural food products, and was circulated to the member bodies in
September 1982.
It has been approved by the member bodies of the following countries :
Australia
Iran Poland
Austria
Iraq Portugal
Bulgaria South Africa, Rep. of
Israel
Canada
Italy Spain
Egypt, Arab Rep. of Tanzania
Kenya
Ethiopia
Korea, Dem. P. Rep. of Thailand
France Mexico United Kingdom
Germany, F. R. USA
Malaysia
Hungary New Zealand USSR
India Philippines Yugoslavia .
The member body of the following country expressed disapproval of the document on
technical grounds :
Netherlands
This International Standard cancels and replaces IS0 Recommendation R 660-1968. of
which it constitutes a technical revision.
@ International Organization for Standardization, 1983 O
Printed in Switzerland
---------------------- Page: 4 ----------------------
SIST ISO 660:1995
INTERNATIONAL STANDARD IS0 660-1983 (E)
Animal and vegetable fats and oils - Determination of
acid value and of acidity
Scope and field of application If the result is reported simply as "acidity", without further
1
definition, this is, by convention, the acidity expressed as oleic
This International Standard specifies two methods (titrimetric acid.
and potentiometric) for the determination of free fatty acids in
L.
animal and vegetable fats and oils. The acids are expressed If the sample contains mineral acids, these are, by convention,
preferably as the acid value or alternatively as acidity calculated determined as fatty acids.
conventionally.
4 Titrirnetric method
The method is applicable to animal and vegetable fats and oils.
It is not applicable to waxes.
4.1 General
This method is most suitable for fats and oils which are not
2 References
strongly coloured.
IS0 661, Animal and vegetable fats and oils - Preparation of
test sample.
4.2 Principle
IS0 5555, Animal and vegetable fats and oils - Sampling.
Dissolution of a test portion in a mixed solvent, followed by
titration of the free fatty acids present with ethanolic potassium
hydroxide solution.
3 Definitions
4.3 Reagents
For the purpose of this International Standard, the following
definitions apply.
All the reagents shall be of recognized analytical quality and the
water used shall be distilled water or water of equivalent purity.
3.1 acid value : Number of milligrams of potassium
hydroxide required to neutralize the free fatty acids in 1 g of fat
4.3.1 Diethyl ether/% % (V/V ethanol, 1 + 1 (V/V
or oil.
mixture.
3.2 acidity : Conventional expression of the percentage free
WARNING - Diethyl ether is very flammable and may
fatty acids.
It shall be used with great
form explosive peroxides.
caution.
According to the nature of the fat or oil, it can be expressed as
indicated in table 1.
Neutralize exactly, just before use, by adding the potassium
hydroxide solution (4.3.2) in the presence of 0,3 ml of the
phenolphthalein solution (4.3.3) per 100 ml of mixture.
Table 1
Molar
NOTE - If it is not possible to use diethyl ether, a mixed solvent of
Expressed as mass
Nature of fat or oil
ethanol and toluene can be used. If necessary, ethanol may be
g/mol
I
replaced by propan-2-01.
Coconut oil, palm kernel oil Lauric acid 200
and similar oils
4.3.2 Potassium hydroxide, ethanolic standard volumetric
Palm oil Palmitic acid 256 solution, c(K0H) = 0,l mol/l, or, if necessary,
c(KOH) = 0.5 mol/l.
=a
Oils from certain cruciferae' Erucic acid
Oleic acid
All other fats and oils 282
The exact concentration of the ethanolic potassium hydroxide
'
solution shall be known, and shall be checked immediately
In the case of rapeseed oil having low erucic acid contents, the
acidity shall be expressed as oleic acid. before use. Use a solution prepared at least 5 days before and
1
---------------------- Page: 5 ----------------------
SIST ISO 660:1995
IS0 660-1983 (E)
4.6.3 Determination
decanted into a brown glass bottle, fitted with a rubber
stopper. The solution shall be colourless or straw yellow.
test portion (4.6.2) in 50 to 150 ml of the pre-
Dissolve the
viously neutralized diethyl ether/ethanol mixture (4.3.1).
NOTE - A stable colourless solution of potassium hydroxide can be
prepared in the following manner. Boil under reflux 1 O00 ml of ethanol
with 8 g of potassium hydroxide and 0.5 g of aluminium pellets for 1 h,
Titrate, whilst swirling the solution, with the 0,l mol/l
then distil immediately. Dissolve the required amount of potassium
potassium hydroxide solution (4.3.2) (see note 3) to the end
hydroxide in the distillate. Allow the whole to stand for several days
of
point as indicated by the indicator (pink colour
and decant the clear supernatant liquid from the deposited potassium
phenolphthalein persisting for at least 10 SI.
carbonate.
The solution can also be prepared without distillation in the following
NOTES
1 O00 ml of ethanol and
manner. Add 4 ml of aluminium butylate to
1 In the case of very low acid values i < 1). it is preferable to pass a
allow the mixture to stand for several days. Decant the supernatant
gentle flow of nitrogen through the test solution.
liquid and dissolve in it the required amount of potassium hydroxide.
This solution is ready for use.
2 The ethanolic standard volumetric potassium hydroxide solution
or sodium hydroxide
(4.3.2) can be replaced by an aqueous potassium
solution when the volume of water introduced does not lead to phase
4.3.3 Phenolphthalein, 10 g/l solution in 95 to 96 % ( V/ V)
-
separation.
ethanol, or alkali blue (in the case of strongly coloured
3 If the quantity of 0,l mol/l potassium hydroxide solution required
samples), 20 g/l solution in 95 to 96 % ( V/ V) ethanol.
exceeds 10 mi, use the 0.5 mol/l solution.
4 If the solu
...
Norme internationale 660
~~~~
INTERNATIONAL ORGANIZATION FOR STANDARDlZATIONOME~YHAPOnHAR OPrAHHJAUHR no CTAHAAPTL43AUHH.ORGANlSATlON INTERNATIONALE DE NORMALISATION
Corps gras d'origines animale et végétale -
L
Détermination de l'indice d'acide et de l'acidité
Animal and vegetable fats and oils - Determination of acid value and of acidity
Première édition - 1983-11-01
- CDU 664.3 : 543.852.1 Réf. no : IS0 660-1983 (FI
5
8 Descripteurs : corps gras animal, corps gras végétal, huile végétale, essai, détermination, acidité, indice d'acide.
z
Prix basé sur 4 pages
---------------------- Page: 1 ----------------------
Ava n t - p r o p os
L‘ISO (Organisation internationale de normalisation) est une fédération mondiale
d’organismes nationaux de normalisation (comités membres de I’ISO). L‘élaboration
des Normes internationales est confiée aux comités techniques de I’ISO. Chaque
comité membre intéressé par une étude a le droit de faire partie du comité technique
correspondant. Les organisations internationales, gouvernementales et non gouverne-
mentales, en liaison avec I’ISO, participent également aux travaux.
Les projets de Normes internationales adoptés par les comités techniques sont soumis
aux comités membres pour approbation, avant leur acceptation comme Normes inter-
nationales par le Conseil de I’ISO.
La Norme internationale IS0 660 a été élaborée par le comité technique ISO/TC 34,
Produits agricoles alimentaires, et a été soumise aux comités membres en
septembre 1982.
Les comités membres des pays suivants l’ont approuvée :
Afrique du Sud, Rép. d’
France Nouvelle-Zélande
Allemagne, R. F. Hongrie Philippines
Australie Inde
Pologne
Autriche Iran Portugal
Bulgarie
Iraq Royaume-Uni
Canada Israël Tanzanie
Corée, Rép. dém. p. de Italie Thailande
Égypte, Rép. arabe d‘ Kenya URSS
Espagne Malaisie USA
Éthiopie Mexique Yougoslavie
Le comité membre du pays suivant l’a désapprouvée pour des raisons techniques :
Pays-Bas
Cette Norme internationale annule et remplace la Recommandation ISO/R 660-1968,
dont elle constitue une révision technique.
0 Organisation internationale de normalisation, 1983 O
Imprimé en Suisse
---------------------- Page: 2 ----------------------
IS0 660-1983 (FI
NORM E I NTE R NATIONALE
Corps gras d‘origines animale et végétale -
Détermination de l‘indice d‘acide et de l’acidité
Si le résultat indique simplement «acidité», sans autre
1 Objet et domaine d‘application
précision, elle est par convention exprimée en pourcentage
La présente Norme internationale spécifie deux méthodes d‘acide oléique.
(titrimétrique et potentiométrique) de détermination des acides
Si l’échantillon contient des acides minéraux, ceux-ci sont par
gras libres dans les corps gras d‘origines animale et végétale.
Les acides sont exprimés, de préférence, par l’indice d‘acide convention déterminés comme acides gras.
‘L
ou, en alternative, par l’acidité calculée conventionnellement.
La méthode est applicable aux corps gras d’origines animale et
4 Méthode titrimétrique
végétale. Elle n’est pas applicable aux cires.
4.1 Généralités
2 Références
Cette méthode convient particulièrement aux corps gras qui ne
sont pas fortement colorés.
IS0 661, Corps gras d’origines animale et végétale -
Préparation de l’échantillon pour essai.
4.2 Principe
IS0 5555, Corps gras d‘origines animale et végétale -
Echan tillonnage.
Mise en solution d’une prise d’essai dans un mélange de
solvants, puis titrage des acides gras libres présents à l’aide
d’une solution éthanolique d’hydroxyde de potassium.
3 Définitions
4.3 Réactifs
Dans le cadre de la présente Norme internationale, les
définitions suivantes sont applicables.
Tous les réactifs doivent être de qualité analytique reconnue, et
l’eau utilisée doit être de l’eau distillée ou de l‘eau de pureté
3.1 indice d’acide : Nombre de milligrammes d’hydroxyde
équivalente.
de potassium nécessaires pour neutraliser les acides gras libres
présents dans 1 g de corps gras.
4.3.1 Oxyde diéthylique/éthanol à 95 YO (V/ v), mélange
1 + 1 (Vlv).
3.2 acidité : Expression conventionnelle du pourcentage
d’acides gras libres.
AVERTISSEMENT - L‘oxyde diéthylique est très inflam-
mable et peut former des peroxydes explosifs. II doit être
Selon la nature du corps gras, l‘acidité peut aussi être exprimée
utilisé en prenant des précautions particulières.
comme indiqué dans le tableau 1.
Neutraliser exactement au moment de l‘emploi avec la solution
d’hydroxyde de potassium (4.3.21, en présence de 0,3 ml de la
Tableau 1
solution de phénolphtaléine (4.3.3) pour 100 ml de mélange.
Masse
molaire
Nature du corps gras Expression
NOTE - S‘il n’est pas possible d’utiliser l’oxyde diéthylique, un
glmol
mélange de solvants formé d’éthanol et de toluère peut être utilisé. Si
nécessaire, l‘éthanol peut être remplacé par le propanol-2.
Huile de coprah, huile de 200
palmiste et huiles similaires
Acide palmitique 256
Huile de palme 4.3.2 Hydroxyde de potassium, solution éthanolique titrée,
c(K0H) = 0,l mol/l, ou, si nécessaire, c(K0H) = 0.5 mol/l.
Acide érucique 338
Huiles de certaines crucifères”
Tous autres corps gras Acide oléique 282
La concentration exacte de la solution éthanolique d‘hydroxyde
de potassium doit être connue, et vérifiée immédiatement avant
Dans le cas de l‘huile de colza à faible teneur en acide érucique,
l‘emploi. Utiliser une solution préparée au moins 5 jours avant
l‘acidité doit être exprimée en acide oléique.
1
---------------------- Page: 3 ----------------------
IS0 660-1983 (F)
4.6.3 Détermination
emploi et décantée dans un flacon en verre brun fermé avec un
bouchon de caoutchouc. La solution doit être incolore ou jaune
Dissoudre la prise d’essai (4.6.2) dans 50 à 150 ml du mélange
paille.
oxyde diéthylique/éthanol (4.3.1 ) préalablement neutralisé.
NOTE - Une solution incolore stable d’hydroxyde de potassium peut
Titrer, en agitant, avec la solution d‘hydroxyde de potassium à
être préparée de la facon suivante. Porter et maintenir durant 1 h à
0,l mol/l (4.3.2) (voir note 3) jusqu‘à virage de l‘indicateur
l‘ébullition à reflux 1 O00 ml d’éthanol avec 8 g d‘hydroxyde de
(coloration rose de la phénolphtaléine persistant durant au
potassium et 0.5 g de rognures d’aluminium. Distiller immédiatement.
Dissoudre dans le distillat la quantité requise d‘hydroxyde de moins 10 s).
potassium. Laisser reposer durant plusieurs jours et décanter le liquide
clair surnageant du précipité de carbonate de potassium. NOTES
Dans le cas d‘indices d’acide très faibles ( < 1). il est préférable de
La solution peut aussi être préparée sans distillation de la facon 1
A 1 O00 ml d’éthanol, ajouter 4 ml de butylate d’aluminium et faire passer un léger courant d‘azote dans la solution d’essai.
suivante.
laisser reposer le mélange durant quelques jours. Décanter le liquide
2 La solution éthanolique titrée d’hydroxyde de potassium (4.3.2)
surnageant et y dissoudre la quantité requise d‘hydroxyde de
peut être remplacée par une solution aqueuse d‘hydroxyde de potas-
potassium. Cette solution est prête pour l’emploi.
sium ou de sodium lorsque le volume d’eau introduit n‘entraîne pas une
séparation de phases.
4.3.3 Phénolphtaléine, solution à 10 g/l dans l‘éthanol à 95
3 Si la quantité nécessaire de solution d‘hydroxyde de potassium à
à 96 % ( V/ VI ou bleu alcalin (dans le cas de corps gras forte-
0,l mol/l dépasse 10 ml, utiliser une solution à 0,5 mol/l.
ment colorés), solution à 20 g/l dans l‘éthanol à 95 à
96 % (V/VI. 4 Si la solution devient trouble pendant le titrage, ajouter une quan-
-
tité suffisante du mélange de solvants (4.3.1) pour donner une solution
claire.
4.4 Appareillage
Matériel courant de laboratoire, et notamment
4.6.4 Nombre de déterminations
Effectuer deux déterminations sur le même échantillon pour
4.4.1 Balance analytique.
essai.
Fiole conique, de 250 ml de capacité.
4.4.2
5 Méthode potentiométrique
4.4.3 Burette, de 10
...
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