prCEN ISO/TS 21296

SLOVENSKI STANDARD
01-december-2025
Oljna semena - Določevanje vsebnosti olja po Randallovi metodi ekstrakcije
(ISO/DTS 21296:2025)
Oilseeds - Determination of oil content by the Randall extraction method (ISO/DTS
21296:2025)
Ölsaaten - Bestimmung des Ölgehalts mittels des Randall-Extraktionsverfahrens
(ISO/DTS 21296:2025)
Graines oléagineuses - Détermination de la teneur en huile par la méthode d'extraction
Randall (ISO/DTS 21296:2025)
Ta slovenski standard je istoveten z: prCEN ISO/TS 21296
ICS:
67.200.20 Oljnice Oilseeds
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

FINAL DRAFT
Technical
Specification
ISO/DTS 21296
ISO/TC 34/SC 2
Oilseeds — Determination of oil
Secretariat: AFNOR
content by the Randall extraction
Voting begins on:
method
2025-10-08
Graines oléagineuses — Détermination de la teneur en huile par
Voting terminates on:
la méthode d'extraction Randall
2025-12-31
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/CEN PARALLEL PROCESSING LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/DTS 21296:2025(en) © ISO 2025

FINAL DRAFT
ISO/DTS 21296:2025(en)
Technical
Specification
ISO/DTS 21296
ISO/TC 34/SC 2
Oilseeds — Determination
Secretariat: AFNOR
of oil content by the Randall
Voting begins on:
extraction method
Graines oléagineuses — Détermination de la teneur en huile par
Voting terminates on:
la méthode d'extraction Randall
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/CEN PARALLEL PROCESSING
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
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Published in Switzerland Reference number
ISO/DTS 21296:2025(en) © ISO 2025

ii
ISO/DTS 21296:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 2
6 Apparatus . 2
7 Sampling . 3
8 Preparation of test sample . 3
8.1 Reduction of laboratory sample .3
8.2 Predrying .4
8.3 Test sample .4
8.3.1 Preliminary remarks .4
8.3.2 Palm kernels .4
8.3.3 Copra (and coconut) .4
8.3.4 Large- and medium-sized seeds (illipe nuts, shea nuts, groundnuts, soya, etc.,
but not sunflower seed or cottonseed) .4
8.3.5 Sunflower seed .5
8.3.6 Cottonseed .5
8.3.7 Small seeds (linseed, rapeseed, etc.) .5
9 Procedure . 5
9.1 Test portion .5
9.2 Determination .6
9.2.1 Preparation of extraction cups .6
9.2.2 Preparation of Randall extraction system .6
9.3 Extraction .6
9.3.1 First extraction .6
9.3.2 Second extraction .6
9.3.3 Third extraction . .7
9.4 Oil content of impurities .7
10 Calculation and expression of results . 7
10.1 General .7
10.2 Determination on product as received (except sunflower seed) .7
10.3 Determination of oil content on product as received for sunflower seed .8
10.4 Determination of palm kernels .8
10.5 Determination when large non-oleaginous foreign bodies have been separated before
the analysis .8
10.6 Determination of groundnuts .9
10.7 Oil content expressed in relation to the dry matter .9
10.8 Oil content expressed on the basis of any specified moisture content .9
11 Performance of the method . 9
12 Test report . 9
Bibliography .11

iii
ISO/DTS 21296:2025(en)
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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO’s adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
The committee responsible for this document is ISO/TC 34, Food products, Subcommittee SC 2, Oleaginous
seeds and fruits and oilseed meals, in collaboration with the European Committee for Standardization (CEN)
Technical Committee CEN/TC 307, Oilseeds, vegetable and animal fats and oils and their by-products —
Methods of sampling and analysis,in accordance with the Agreement on technical cooperation between ISO
and CEN (Vienna Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO/DTS 21296:2025(en)
Introduction
This document is an alternative method for the determination of oil content in oilseeds. In case of dispute or
any conflicts, ISO 659 remains the reference method.

v
FINAL DRAFT Technical Specification ISO/DTS 21296:2025(en)
Oilseeds — Determination of oil content by the Randall
extraction method
1 Scope
This document specifies a method using automated Randall extraction for the determination of the hexane
extract (or light petroleum extract), called the “oil content”, of oilseeds used as industrial raw materials.
The procedure for sunflower seed is different from those for others seeds as it includes an additional
moisture content determination after the seed has been ground to prepare the test sample.
If required, the pure seeds and the impurities can be analysed separately. In the case of groundnuts, the
pure seeds, the total fines, the non-oleaginous impurities and the oleaginous impurities can be analysed
separately.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 658, Oilseeds — Determination of content of impurities
ISO 664, Oilseeds — Reduction of laboratory sample to test sample
ISO 665, Oilseeds — Determination of moisture and volatile matter content
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
hexane extract
“oil content”
all the substances extracted under the operating conditions specified in this document, expressed as a
percentage by mass of the product as received, or on the cleaned seed
Note 1 to entry: On request, it may be expressed relative to the dry matter.
4 Principle
Oil is extracted from a test portion, with hexane or light petroleum as a solvent, in an automated Randall
extractor. The test portion is submerged in boiling solvent prior to rinsing in cold solvent, reducing the
time needed for extraction. After extraction, the solvent is evaporated and recovered by condensation. The
resulting oil content is determined gravimetrically after drying (see Figure 1).

ISO/DTS 21296:2025(en)
Stage 1: The sample is immersed in boiling solvent and the extractable material is liberated from the sample.
Stage 2: The level of the solvent is lowered below the extraction thimble. The excess solvent is collected in
the rear solvent recovery tank.
Stage 3: The material is extracted by the refluxed, condensed solvent and is concentrated in the extraction
beaker.
Stage 4: The bulk of the solvent is distilled over into the rear storage tank for later recovery.
Stage 5: The extraction beakers are lifted from the hotplate automatically. Some of the residual solvent may
be removed via convection heating.
Figure 1 — Principle and steps of Randall extraction
5 Reagents
Use only reagents of recognized analytical grade.
5.1 Technical hexane, n-hexane or light petroleum, essentially composed of hydrocarbons with six
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, and which has a bromine value of less than 1. The residue on complete
evaporation shall not exceed 2 mg per 100 ml.
6 Apparatus
The usual laboratory apparatus and, in particular, the following shall be used.
6.1 Automatic Randall extraction system, equipped with several extraction units, consisting of
a heating plate, an extraction cup or beaker (6.2) and a condenser enabling solvent recovery, fitted with
fluoroelastomer or polytetrafluoroethylene seals compatible with petroleum ether or hexane. The system is
also equipped with a control box allowing us to set the extraction system.
6.2 Extraction cups or extraction beaker, of aluminium or glass, compatible with the solvent extraction
system (6.1) and able to receive at least 80 ml of solvent.
6.3 Extraction thimbles, of cellulose, free from petroleum ether or hexane extractable products. The
most common size used is 33 mm × 80 mm, but depending on extraction unit configuration, another size can
be used. See the manufacturer’s instructions.
6.4 Cotton wool, free from petroleum ether or hexane extractable products.
6.5 Drying oven, capable of being maintained at (103 ± 2) °C.
6.6 Desiccator, containing an efficient desiccant (e.g. silica gel, with orange indicator, or P O ).
2 5
ISO/DTS 21296:20
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