SIST ISO 3632-2:2011

INTERNATIONAL ISO
STANDARD 3632-2
First edition
2010-10-01
Spices — Saffron (Crocus sativus L.) —
Part 2:
Test methods
Épices — Safran (Crocus sativus L.) —
Partie 2: Méthodes d'essai
Reference number
©
ISO 2010
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 2010
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 2010 – All rights reserved

Contents Page
Foreword .iv
1 Scope.1
2 Normative references.1
3 Terms and definitions .1
4 Tests and sample sizes.2
5 Identification test.4
6 Microscopic examination of saffron.5
7 Determination of moisture and volatile matter content.8
8 Determination of floral waste content of saffron in filaments and cut filaments .10
9 Determination of foreign matter content of saffron in filaments and cut filaments.10
10 Crushing and sieving of the samples for tests described in Clauses 6, 14, 15 and 16 .11
11 Determination of extract soluble in cold water .12
12 Determination of total ash .12
13 Determination of acid-insoluble ash .12
14 Determination of the main characteristics using a UV-vis spectrometric method.12
15 Detection of artificial coloring: identification of synthetic water-soluble acidic
colorants — Thin-layer chromatography method.14
16 Detection of artificial coloring: identification of synthetic water-soluble acidic
colorants — High performance liquid chromatography (HPLC) .18
Annex A (informative) Example for the expression of results for a microscopic examination .25
Annex B (informative) Photographic references for microscopic identification.27
Annex C (informative) Example of a UV-vis profile of an aqueous extract of saffron .30
Annex D (informative) Examples of chromatograms .31
Bibliography.36

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 3632-2 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 7, Spices,
culinary herbs and condiments.
This second edition of ISO 3632-2 cancels and replaces ISO/TS 3632-2:2003, which has been technically
revised.
ISO 3632 consists of the following parts, under the general title Spices — Saffron (Crocus sativus L.):
⎯ Part 1: Specification
⎯ Part 2: Test methods
iv © ISO 2010 – All rights reserved

INTERNATIONAL STANDARD ISO 3632-2:2010(E)

Spices — Saffron (Crocus sativus L.) —
Part 2:
Test methods
1 Scope
This part of ISO 3632 specifies test methods for dried saffron obtained from the Crocus sativus L. flower.
It is applicable to saffron:
a) filaments and cut filaments;
b) powder.
2 Normative references
The following referenced documents are indispensable for the application 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 928, Spices and condiments — Determination of total ash
ISO 930, Spices and condiments — Determination of acid-insoluble ash
ISO 941, Spices and condiments — Determination of cold water-soluble extract
ISO 948, Spices and condiments — Sampling
ISO 3632-1, Spices — Saffron (Crocus sativus L.) — Part 1: Specification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 3632-1 and the following apply.
3.1
moisture and volatile matter content
loss of mass fraction determined under the conditions specified in this part of ISO 3632
NOTE Moisture and volatile matter content is expressed as a percentage mass fraction of the sample.
3.2
colouring strength
1%
A , 440 nm
1cm
absorbance at the maximum wavelength (about 440 nm) of crocins for a 1 g/100 ml solution of test sample
using a 1 cm quartz cell
NOTE Colouring strength is mainly due to the content of crocins.
3.3
UV-vis profile of saffron extract
spectrum obtained between 200 nm and 700 nm
NOTE An example is given for information in Figure C.1.
3.4
limit of detection
LOD
minimum amount or concentration of the analyte in a test sample which can be detected reliably, but not
necessarily quantified, as demonstrated by a collaborative trial or other appropriate validation
3.5
minimum required performance limit
MRPL
minimum content of an analyte in a sample, which at least has to be detected and confirmed
4 Tests and sample sizes
4.1 Minimum mass of the laboratory sample
Sampling methods for spices and condiments are specified in ISO 948.
Considering the high cost of saffron, the mass of sample received in the laboratories for carrying out the tests
is often limited. The minimum mass of the laboratory sample shall be 23 g (11,5 g × 2) for saffron filaments
and cut filaments and 13,5 g (6,75 g × 2) for saffron powder in order to carry out the standard analyses in
duplicate.
It is recommended that larger quantities of sample be placed at the disposal of the laboratories in case of
dispute.
Since the mass of the test portion is low, it is advisable that it be taken from a homogenized sample.
4.2 Tests required and test sample sizes
See Table 1 for saffron in filaments, cut filaments and Table 2 for saffron in powder.
2 © ISO 2010 – All rights reserved

Table 1 — Saffron in filaments and cut filaments forms
Test
Analysis Procedure Corresponding
sample Comments
step (laboratory sample: 11,5 g × 2 = 23 g) clause
g
New test sample
1 Identification test 5 5
Non-destructive test
2 Microscopic examination 0,05 Test sample from step 1 6
Test sample from step 1
3 Determination of floral waste content 3 8
Non-destructive test
Test sample from step 3
4 Determination of foreign matter 3 9
Test sample is reconstituted after
reincorporating floral waste
Determination of extract soluble in
5 2 Test sample from step 4 11
cold water
New test sample
Determination of moisture and
Keep the test sample for
6 2,5 7
volatile matter content
determination of total ash and acid-
insoluble ash
7 Determination of total ash 2 Remains of the test sample from step 6 12
8 Determination of acid-insoluble ash — Test sample produced after step 7 13
New test sample
Carry out the sieving in accordance
with Clause 10 to obtain a powder of
which 95 % mass fraction passes
9 Crushing and sieving 4 10
through a 500 µm sieve.
Reincorporate whatever remains on
the sieve in the receptacle of the
sieve
10 Determination of main characteristics 0,5 Test sample from step 9, after sieving 14
Test sample from step 9, before
sieving
Thin-layer chromatography (TLC):
HPLC (step 12) may alternatively or
11 0,5 15
identification of artificial colorants
additionally be performed. In the latter
case, use the extract for both
methods
Test sample from step 9, before
sieving
High performance liquid
TLC (step 11) may alternatively or
12 chromatography (HPLC): 0,5 16
additionally be performed. In the latter
identification of artificial colorants
case, use the extract for both
methods
NOTE There remain 4,50 g laboratory sample which can be used for further tests or to repeat certain analyses if necessary.

Table 2 — Saffron in powder form
Test
Analysis Procedure Corresponding
sample Comments
step clause
(laboratory sample: 6,75 g × 2 = 13,5 g)
g
New test sample
1 Identification test 0,2 5
Do not continue with the analysis if
the colorimetric analysis is not correct
2 Microscopic examination 0,05 New test sample 6
New test sample
Determination of moisture and volatile
Keep the test sample for
3 2,5 7
matter content
determination of total ash and acid-
insoluble ash
4 Determination of total ash 2 Remains of the test sample from step 3 12
5 Determination of acid-insoluble ash — Remains of the test sample from step 4 13
New test sample
Verify that 95 % mass fraction of the
powder passes through a 500 µm
6 Crushing and sieving 4 10
sieve. Reincorporate whatever
remains on the sieve in the receptacle
of the sieve
Determination of extract soluble in cold
7 2 Test sample from step 6 11
water
8 Determination of main characteristics 0,5 Test sample from step 6, after sieving 14
Test sample from step 6, before
sieving
Thin-layer chromatography (TLC):
HPLC (10) may alternatively or
9 0,5 15
identification of artificial colorants
additionally be performed. In the latter
case, use the extract for both
methods
Test sample from step 6, before sieving
High performance liquid
TLC (9) may alternatively or
10 chromatography (HPLC): 0,5 16
additionally be performed. In the latter
identification of artificial colorants
case, use the extract for both methods
NOTE There remain 1 g laboratory sample which can be used for further tests or to repeat certain analyses if necessary.
5 Identification test
5.1 General
This preliminary test may make the subsequent analyses unnecessary if it shows that the saffron is not pure.
5.2 Saffron in filaments and cut filaments
5.2.1 Principle
The saffron is examined visually with a magnifying glass.
5.2.2 Apparatus
5.2.2.1 Magnifying glass, with a magnification of 10 times max.
5.2.2.2 Watch glass, of suitable size.
4 © ISO 2010 – All rights reserved

5.2.3 Procedure
Spread out the test sample of saffron in filaments and cut filaments (Table 1) on the watch glass (5.2.2.2) and
examine it with the magnifying glass (5.2.2.1).
5.2.4 Interpretation of results
All the filaments shall belong to the plant Crocus sativus L.
Reject the sample if vegetable matter other than that belonging to Crocus sativus L. is found.
5.3 Saffron in powder form
5.3.1 Principle
A colorimetric reaction is used.
5.3.2 Reagents
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and distilled or
demineralized water or water of equivalent quality.
5.3.2.1 Sulfuric acid, mass concentration 1,19 g/l.
5.3.2.2 Diphenylamine solution. Add 0,1 g diphenylamine to 20 ml sulfuric acid (5.3.2.1) and 4 ml water.
The diphenylamine shall not produce any coloured reaction with the sulfuric acid.
...