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IS0
I NT ERN AT1 ON A L O RG A N IZ AT1 ON FOR STAND AR DI ZATl ON
IS0 RECOMMENDATION
R 659
OLEAGINOUS SEEDS
DETERMINATION OF OIL CONTENT
1 st EDITION
February 1968
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The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.
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BRIEF HISTORY
The IS0 Recommendation R 659, Oleaginous seeds - Determination of oil content, was drawn
up by Technical Committee ISOlTC 34, Agricultural food products, the Secretariat of which is held
by the Magyar Szabvanyügyi Hivatal (MSZH).
Work on this question by the Technical Committee began in 1960 and led, in 1963, to the
L adoption of a Draft IS0 Recommendation.
In March 1966, this Draft IS0 Recommendation (No. 900) was circulated to all the IS0
Member Bodies for enquiry. It was approved, subject to a few modifications of an editorial nature,
by the following Member Bodies :
Poland
Australia Hungary
India Romania
Belgium
Bulgaria Iran South Africa,
Chile Ireland Rep. of
Colombia Israel Turkey
Czechoslovakia Italy U.A.R.
Finland Netherlands United Kingdom
France New Zealand U.S.S.R.
Ge~~y Norway Yugoslavia
No Member Body opposed the approval of the Draft.
The Draft IS0 Recommendation was then submitted by correspondence to the IS0 Council
which decided, in February 1968, to accept it as an IS0 RECOMMENDATION.
L
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ISO/R 659-1968 (E)
IS0 Recommendation R 659 February 7968
OLEAGINOUS SEEDS
DETERMINATION OF OIL CONTENT
1. SCOPE
This IS0 Recommendation describes a method for the determination of the oil content of oleaginous
seeds used as primary industrial materials.
2. DEFINITION
By oil is meant the total quantity of substances extracted under the operating conditions given below.
3. PRINCIPLE
3.1 Determination of the oil content of the material as received (pure seed plus impurities) by
extraction in a suitable apparatus, with a suitable solvent, n-Hexane or light petroleum.
3.2 It is possible, if required, to analyse the pure seed and the impurities separately.
3.3 In the case of groundnuts it is possible, if required, to analyse the pure seed, the total fines, the
non-oleaginous impurities and the oleaginous impurities separately.
4. REAGENTS
4.1 n-Hexane; failing this, light petroleum distilling between 40 and 60 "C and having a bromine
value below 1. For either solvent the residue on complete evaporation should not exceed 0.002
g/100 ml.
4.2 Sund, washed with hydrochloric acid and calcined.
4.3 Pumice-stone, in small granules, previously dried.
HydrochIoric acid, concentrated, d = 1 .I 9.
4.4
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ISO/R 659-1968 (E)
5. APPARATUS
5.1 Suitable extraction apparatus (capacity of flask, 200 to 250 mi).
5.2 Electric heating bath (sand-bath, water bath, etc.).
Analytical balance.
5.3
5.4 Electric oven with temperature regulation.
Mechanical mill, easy to clean, corresponding to the nature of the seeds and allowing grinding
5.5
to be done without heating or appreciable loss of moisture and oil.
5.6 Mechanicalgrater or, failing this, hand grater.
5.7 Mortar and pestle, of porcelain, iron or bronze, or, preferably, suitable microgrinder.
Extraction thimble and cotton wool, free from matter soluble in n-Hexane or light petroleum.
5.8
Metal vessel, flat-bottomed, diameter about 100 mm, height about 40 mm.
5.9
Porous vessel of ceramic material, cylindrical, internal diameter 68 mm, external diameter
5.10
80 mm, height 85 mm, thickness of walls and base 6 mm.
Fumigation oven, with temperature control.
5.11
5.12 Pipette, 2 ml, graduated in tenths of a millilitre.
Watch glass, diameter 80 to 90 mm.
5.13
6. PROCEDURE
6.1 Preparation of sample
6.1.1 Carry out the operations described below on the analysis sample obtained according to IS0
Recommendation R 664, Oleaginous seeds - Reduction of contract samples to samples for
analysis. If, before the reduction of the contract sample, large non-oleaginous foreign bodies
have been separated, this should be taken into account in the calculations (see clause 7.3.3).
According to the requirements of the contract, use the analysis sample without, or after,
separation of the impurities.
6.1.2 For copra, grate the product with a hand grater or preferably with the mechanical grater
(5.6), which can deal with the whole sample for analysis. Hand operation does not allow the
whole sample for analysis to be grated. Endeavour to obtain a sub-sample which is as repre-
sentative as possible. The thickness and the colour of the different pieces should be taken
into account.
The length of the grated particles may exceed 2 mm, but should not be greater than 5 mm.
Mix the particles carefully and carry out the determination without delay.
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ISO/R 659-1968 (E)
6.1.3 For medium-sized seeds (e.g. sunflower, groundnut, soya) with the exception of cottonseed
with adherent linters, crush the sample for analysis, in the previously well cleaned mechani-
cal mill (5.9, until particles are obtained with a major dimension not greater than 2 mm.
Reject the first grindings (about 1/20 of the sample) and collect the rest. Mix carefully and
carry out the determination without delay.
6.1.4 For cottonseed with adherent linters, weigh to the nearest 0.01 g in the tared metal vessel
(5.9) about 60 g of the sample for analysis without separation of impurities. Put the vessel
and seed in the oven (5.4) previously heated to 130 OC and leave to dry for 2 hours at
130 k 2 OC, then remove the vessel from the oven and allow to cool in air for about 30 min.
Transfer the dried seed to the porous ceramic vessel (5.10), the inside walls and base of
which have been previously moistened with 1.5 ml of concentrated hydrochloric acid (4.4)
by means of the pipette (5.12), taking care that the acid is completely absorbed without
forming adherent drops. Close the vessel with the watch glass (5.13) and put it in the fumi-
gation oven (5.1 1). Heat so as to reach 115 OC in 30 minutes; do not heat beyond this tem-
perature and maintain it for another 30 minutes.
Take the vessel out of the oven, allow to cool for 1 hour in air, reweigh the treated seed to
the nearest 0.01 g, then grind the seed in the mechanical mill (5.5) and continue as described
in clause 6.1.3.
6.1.5 Small seeds (e.g. linseed, colza, etc.) are analysed without previous mechanical grinding.
6.2 Test portion
6.2.1 The test portion should be representative of the analysis sample.
6.2.2 'Weigh, to the nearest 0.01 g, about 10 g.
- of the grated product (6.1.2), as soon as it has been grated, in the case of copra.
- of the ground product (6.1.3) as soon as it has been ground, in the case of medium-
sized seeds except cottonseed with adherent linters,
- of the ground product (6.1.4) as soon as it has been ground, in the case of cottonseed
with adherent linters,
- of the previously well mixed sample, in the case of small seeds.
6.3 Determination
6.3.1 In the case of copra and medium-sized seeds, includingcottonseed with adherent linters, put
the test portion in the thimble (5.8) and plug it with a wad of cotton wool.
6.3.2 For small seeds, grind the test sample in the mortar or micro-grinder (5.7), taking care not to
leave any seeds intact. Transfer, without loss, the ground seeds to the thimble (5.8), using a
spatula. Wipe the mortar and pestle, or the bowl of the micro-grinder and the spatula, with
a wad of cotton wool (5.8) soaked with solvent (4.1) and plug the thimble with this wad.
6.3.3 In the case of groundnuts, a test portion of about 10 g may be put into the extraction
thimble (5.8), this comprising the separated fractions of pure seed, non-oleaginous im-
purities, oleag
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