SIST EN ISO 659:1998

SLOVENSKI STANDARD
SIST EN ISO 659:1998
01-december-1998
2OMQDVHPHQD'RORþHYDQMHROMD5HIHUHQþQDPHWRGD,62
Oilseeds - Determination of oil content (Reference method) (ISO 659:1998)
Ölsamen - Bestimmung des Ölgehaltes (Referenzverfahren) (ISO 659:1998)
Graines oléagineuses - Détermination de la teneur en huile (Méthode de référence) (ISO
659:1998)
Ta slovenski standard je istoveten z: EN ISO 659:1998
ICS:
67.200.20 Oljnice Oilseeds
SIST EN ISO 659:1998 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 659:1998

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SIST EN ISO 659:1998

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SIST EN ISO 659:1998

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SIST EN ISO 659:1998
INTERNATIONAL ISO
STANDARD 659
Second edition
1998-06-01
Oilseeds — Determination of oil content
(Reference method)
Graines oléagineuses — Détermination de la teneur en huile (Méthode
de référence)
A
Reference number
ISO 659:1998(E)

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SIST EN ISO 659:1998
ISO 659:1998(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.
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.
International Standard ISO 659 was prepared by Technical Committee
ISO/TC 34, Agricultural food products, Subcommittee SC 2, Oleaginous
seeds and fruits.
This second edition cancels and replaces the first edition (ISO 659:1988),
which has been technically revised.
Annexes A and B of this International Standard are for information only.
©  ISO 1998
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 the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
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SIST EN ISO 659:1998
©
INTERNATIONAL STANDARD  ISO ISO 659:1998(E)
Oilseeds — Determination of oil content (Reference
method)
1 Scope
This International Standard specifies a reference method for the determination of the hexane extract (or light
petroleum extract), called “oil content”, of oil seeds used as industrial raw materials.
NOTE If required, the following may be analysed separately:
– the pure seeds and the impurities (see 9.3);
– in the case of groundnuts, the pure seeds, the total fines, the non-oleaginous impurities and the oleaginous
impurities.
The method has been tested on rapeseed, soya beans and sunflower seeds. This does not, however, preclude its
applicability to other commercial seeds.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of the publication, the editions indicated were valid. All standards are subject to
revision, and parties to agreements based on the International Standard are encouraged to investigate the
possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
ISO 658:1988, Oilseeds — Determination of impurities.
ISO 664:1990, Oilseeds — Reduction of laboratory sample to test sample.
ISO 665:1977, Oilseeds — Determination of moisture and volatile matter content.
3 Definition
For the purposes of this International Standard, the following definition applies.
3.1 hexane extract, called “oil content”
all the substances extracted under the operating conditions specified in this International Standard, expressed as a
percentage by mass of the product as received [tale quale] or on the cleaned seed.
NOTE On request, it may be expressed relative to the dry matter.
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SIST EN ISO 659:1998
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ISO 659:1998(E)
4 Principle
Extraction of a test portion, in a suitable apparatus, with technical hexane or light petroleum. Elimination of the
solvent and weighing of the extract obtained.
5 Reagent
5.1 Technical hexane, n-hexane or light petroleum, essentially composed of hydrocarbons with 6 carbon
atoms, of which less than 5 % distils below 40 °C and more than 95 % distils between 40 °C and 60 °C or between
50 °C and 70 °C. The residue on complete evaporation shall not exceed 2 mg per 100 ml.
6 Apparatus
Usual laboratory apparatus and, in particular, the following.
6.1 Analytical balance.
6.2 Mechanical mill, easy to clean, appropriate for the nature of the oilseeds, and allowing the oilseeds to be
ground to a uniform particle size without heating or appreciable change in moisture, volatile matter or oil content.
NOTE The following mills have been found to give satisfactory results:
1)
– the Christy Norris 8" Laboratory Mill with perforated plate of bar-type screens depending on seed type (e.g.
0,8 mm perforated plate, 3 mm and 6 mm bar screens; see 8.3.2, 8.3.3 and 8.3.4);
1)
– the Ultra Centrifugal Mill (UCM) (Glen Creston) with 1 mm screen for sunflower seeds and other screens according
to seed type.
Other mills may be satisfactory, provided they conform to the criteria given above.
6.3 Mechanical micro-grinder, capable of producing a fineness of grinding of the oilseeds of less than 160 μm,
with the exception of the “shell”, particles of which may reach 400 μm.
2)
NOTE A “Dangoumau” type analytical grinder with a 150 ml cylinder and 1 cm, 2 cm and 3 cm diameter steel balls
(approximately 7 g, 30 g and 130 g) according to the sample being ground, has been found to be suitable.
The following microgrinders have also been found to be suitable:
2) 2) 2) 2) 2)
– Retsch , IE Retsch , Planetary Ball Mill , S1 and S2 Centrifugal Ball Mill , Batam Mikro Pulverizer Hammer Mill ,
2) 2) 2)
IKA Mill , Fritch Pulverisette 5 Planetary Ball Mill and Steam Mill .
6.4 Extraction thimble and cotton wool, free from matter soluble in hexane or light petroleum.
6.5 Suitable extraction apparatus, fitted with a flask of capacity 200 ml to 250 ml.

1)  The Christy Norris 8" Laboratory Mill and the Ultra Centrifugal Mill (UCM) (Glen Creston) are examples of suitable products
available commercially. This information is given for the convenience of users of this International Standard and does not
constitute an endorsement by ISO of these products.
2)  The above-mentioned microgrinders are examples of suitable products available commercially. This information is given for
the convenience of users of this International Standard and does not constitute an endorsement by ISO of these products.
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3)
NOTE Straight-through extractors, for example the Butt, Smalley or Bolton-Williams type , are suitable.
The use of other extractors is conditional upon the results of a test on a standard material of known oil content to
confirm the suitability of the apparatus.
6.6 Pumice stone, in small particles, or other anti-bumping granules, previously dried in an oven at (130 ± 2) °C
and cooled in a desiccator.
6.7 Apparatus for safely removing solvent from extraction thimble (for example in a current of warm air).
6.8 Electric heating bath (sand bath, water bath, heating mantel, etc.) or hot-plate.
6.9 Electrically heated oven, with thermostatic control, capable of being maintained at (103 ± 2) °C. The oven
should be capable of being used at either atmospheric or reduced pressure (see 9.2.3).
, containing an efficient desiccant (e.g.silica gel with blue indicator, or P O ).
6.10 Desiccator
2 5
6.11 Electrically heated oven, capable of being maintained at (130 ± 2) °C (for cottonseed, see 8.3.5).
6.12 Metal dish, flat-bottomed, of diameter 100 mm and height approx. 40 mm.
7 Sampling
Sampling is not part of the method specified in this International Standard. A recommended sampling method is
given in ISO 542.
It is important that the laboratory receive a sample which is truly representative and has not been damaged or
changed during transport and storage.
8 Preparation of test sample
8.1 Reduction of laboratory sample
Prepare the test sample in accordance with ISO 664. If large non-oleaginous foreign bodies have been separated
before reduction of the laboratory sample, make allowance for this in the calculation (see 10.1.3). According to the
requirements of the contract, take a sample as received or after separation of the impurities.
8.2 Predrying
8.2.1 The moisture content of the test portion (9.1) shall be less than 10 % (m/m) when extraction of the oil (9.2) is
commenced.
NOTE Failure to observe this may result in an incorrect result and invalidate the analysis.

3)  The Butt, Smalley or Bolton-Williams straight-through extractors are examples of suitable products available commercially.
This information is given for the convenience of users of this International Standard and does not constitute an endorsement by
ISO of these products.
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Use a rapid screening method to assess the moisture content of the analysis sample (8.1). If it is greater than 10 %
(m/m), reduce it to less than 10 % (m/m) by drying the analysis sample (8.1) in a dish in an oven maintained at a
temperature not greater than 80 °C. Store the partially dried material in an air-tight jar. Determine the moisture
contents of the partially dried analysis sample and the original sample according to the method given in ISO 665
and make allowance for this in the final calculation (see 10.1.6).
8.3 Test sample
8.3.1 Preliminary remarks
It is essential that the oil extractions are carried out within 30 min of grinding, especially if the free fatty acids content
of the extracted oil is to be determined.
Care shall be taken to clean all mills thoroughly before and after each sample has been ground. Any material
adhering to the mill shall be incorporated with the bulk of the ground material.
NOTE In the following test “seed” or “kernels” implies both whole seeds or kernels and broken fragments of them.
8.3.2 Palm kernels
Shell is considered to be part of the impurities, even when attached to the kernels. Shell and dirt shall be separated
quantitatively from the kernels before analysis.
Shell is hard and difficult to mill. It is almost impossible to obtain a homogeneous sample if kernels and impurities
are milled together. If the oil content of the whole sample [tale quale] is required, analyse the kernels and impurities
(shell and dirt) separately and calculate the oil content (see 10.1.2).
Prepare the test samples by grinding separately, 600 g of the well-mixed kernels, and all of the shell and dirt
separated during the quantitative determination of impurities according to the method given in ISO 658.
The following milling techniques have been found to be suitable:
4)
– for pure kernels: grind in a Christy Norris Laboratory Mill (6.2) with a 6 mm bar screen;
– for shell and dirt: grind for 10 min in a microgrinder (6.3) using a 3 cm steel ball.
8.3.3 Copra (and coconut)
The entire sample should be frozen before milling in the mechanical mill (6.2).
4)
The Christy Norris Laboratory Mill with a 6 mm screen has been found to be satisfactory. The length of particles
shall be approximately 2 mm but shall not be greater than 5 mm. Mix the particles carefully and carry out the
determination without delay.
Care shall be taken to avoid condensation of moisture onto the seeds during and after grinding.
8.3.4 Large and medium sized seeds (illipe, sheanuts, sunflower, groundnuts, soya, etc.)
Except in the case of cottonseed, grind the test sample in the mechanical mill (6.2), until the major dimension of the
particles obtained is not greater than 2 mm. Reject the first particles (about one-twentieth of a sample), collect the
rest, mix carefully and carry out the determination without delay.

4)  Refer to footnote 1).
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The following milling techniques have been found to be satisfactory:
4) 4)
– for soya: Christy Norris Laboratory Mill with 0,8 mm perforated plate, or Ultra Centrifugal Mill with 1 mm
screen;
4)
– for sunflower: UCM Mill with 1 mm screen;
4)
– for groundnuts: Christy Norris Laboratory Mill with 3 mm bar screen; with samples containing more than
about 45 % (m/m) of oil, care shall be taken to avoid, as far as possible, the formation of a pasty mass;
– other seeds: 6 mm bar screen.
NOTE The grinding of very oily seeds can often be improved if the seeds are first frozen at -10 °C to -20 °C, but
great care should be taken to avoid condensation of moisture onto the seeds during and after grinding.
8.3.5 Cottonseed
Weigh, to the nearest 1 mg in the tared metal dish (6.12), about 15 g from the sample as received. Place the dish
and seeds in the oven (6.11) previously heated to 130 °C, and leave to dry for 2 h at (130 ± 2) °C. Then remove the
dish from the oven and allow to cool in air for about 30 min. Transfer the whole test portion to a grinder or mill (6.2)
and grind to break up the seeds and linters. Transfer the ground material to an extraction thimble (6.4) and proceed
with the determination.
8.3.6 Small seeds (linseed, rapeseed, etc.)
Take a representative portion of approximately 100 g from the sample as received and grind it (6.2) so that no
whole seeds remain. Ensure that any fine material remaining in the mill is incorporated into the bulk of the ground
material and that the whole is thoroughly mixed. Care shall be taken that moisture is not lost from
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