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SLOVENSKI STANDARD
01-junij-2022
Nadomešča:
SIST EN 1787:2001
Živila - Določevanje obsevanosti živil, ki vsebujejo celulozo, s spektroskopijo ESR
Foodstuff - Detection of irradiated foodstuff containing cellulose by ESR spectroscopy
Lebensmittel - ESR-spektroskopischer Nachweis von bestrahlten cellulosehaltigen
Lebensmitteln
Produits alimentaires - Détection par spectroscopie RPE d'aliments ionisés contenant de
la cellulose
Ta slovenski standard je istoveten z: EN 1787:2022
ICS:
67.050 Splošne preskusne in General methods of tests and
analizne metode za živilske analysis for food products
proizvode
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 1787
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2022
EUROPÄISCHE NORM
ICS 67.050 Supersedes EN 1787:2000
English Version
Foodstuff - Detection of irradiated foodstuff containing
cellulose by ESR spectroscopy
Produits alimentaires - Détection par spectroscopie Lebensmittel - ESR-spektroskopischer Nachweis von
RPE d'aliments ionisés contenant de la cellulose bestrahlten cellulosehaltigen Lebensmitteln
This European Standard was approved by CEN on 14 February 2022.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1787:2022 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 5
5 Apparatus and equipment . 6
6 Procedure . 6
6.1 Sample preparation . 6
6.1.1 General. 6
6.1.2 Shells and stones . 6
6.1.3 Spices . 6
6.1.4 Strawberries . 7
6.2 ESR Spectroscopy . 7
6.2.1 Spectrometer settings . 7
6.2.2 Analysis of sample . 8
7 Evaluation . 8
7.1 G-value calculation . 8
7.2 Identification of irradiated samples . 8
8 Limitations . 9
9 Validation . 9
10 Test report . 10
Annex A (informative) Example Figures . 11
Annex B (informative) Further information on the applicability . 13
Bibliography . 14
European foreword
This document (EN 1787:2022) has been prepared by Technical Committee CEN/TC 275 “Food analysis -
Horizontal methods”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by October 2022, and conflicting national standards shall
be withdrawn at the latest by October 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 1787:2000.
The predecessor of this document was elaborated on the basis of a protocol developed following a
concerted action supported by the Commission of European Union (XII C.5). Experts and laboratories
from EU and EFTA countries, contributed jointly to the development of this protocol.
In comparison with the previous edition, the entire document was editorially revised according to
current rules. Additionally, the following technical modifications have been made:
a) the scope was supplemented by the information, that chemical bleaching of nuts in shells can lead to
comparable signals;
b) clause “Terms and definitions” was added;
c) scientific language usage of clause “Principle” had been clarified;
d) former 4.1, 4.2 and 4.7 were updated and a footnote added for the g-value calculation;
e) clause “Procedure” was scientifically refined, its normative character (i.e. provisions set out)
modified towards more exemplary/suggestive expressions of provision and aligned with EN 13708;
f) subclause “General” was added to subclause “Sample preparation”;
g) clause “Evaluation” was amended by supplementing two subclauses, 7.1 “G-value calculation” and
7.2 “Identification of irradiated samples”, in alignment with EN 13708, including implementing its
former content into 7.2, whereas “6,0 mT” was refined to “6,05 mT ± 0,05 mT”;
h) clause “Limitations” was extended;
i) Figures A.5 and A.7 of irradiated but bleached nutshells from hazelnuts and walnuts and Figures A.6
and A.8 of irradiated (not bleached) nutshells from hazelnuts and walnuts were added;
j) Annex B was extended by the matrix hazelnuts;
k) the Bibliography was updated and extended by entry [23], [24] and [25].
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
1 Scope
This document specifies a method for the detection of foodstuff containing cellulose which have been
treated with ionizing radiation, by analysing the electron spin resonance (ESR) spectrum, also called
electron paramagnetic resonance (EPR) spectrum, of the foodstuff, see [1] to [13].
Interlaboratory studies have been successfully carried out with pistachio nut shells, [14] to [18], paprika
powder [19] and [20] and fresh strawberries [21]. However, it has been shown that chemical bleaching
of nuts in shells can lead to comparable signals. For further information, see Clause 8 on limitations.
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.
EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696)
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at
— ISO Online browsing platform: available at
4 Principle
ESR spectroscopy detects paramagnetic centres (e.g. radicals). They are either due to irradiation, or to
other compounds present. An intense external magnetic field produces a difference between the energy
levels of the electron spins m = +½ and m = −½, leading to resonance absorption of an applied
s s
microwave beam in the spectrometer. ESR spectra are conventionally displayed as the first derivative of
the absorption with respect to the applied magnetic field.
The magnetic field and microwave frequency values depend on the experimental arrangements (sample
size and sample holder), while their ratio (i.e. g value) is an intrinsic characteristic of the paramagnetic
centre and its local co-ordination. For further information, see [1] to [13].
Radiation treatment produces specific radicals that can be mostly detected in solid and dry parts of the
foodstuff. The intensity of the signal obtained increases with the concentration of the paramagnetic
compounds and thus with the applied dose.
5 Apparatus and equipment
Usual laboratory apparatus and, in particular, the following:
5.1 Commercially available X-Band ESR spectrometer including magnet (electro or permanent),
microwave bridge, console with field- controller and signal-channel, rectangular or cylindrical cavity .
2
5.2 ESR tubes, suitable for the ESR spectrometer used (e.g. Suprasil quartz tubes).
5.3 Balance, accuracy of 1 mg (optional).
5.4 Laboratory vacuum oven or freeze dryer.
5.5 Electric blender.
5.6 Filter paper.
5.7 Scalpel, pincers.
5.8 Water complying with at least grade 3 of EN ISO 3696.
6 Procedure
6.1 Sample preparation
6.1.1 General
Do not grind the samples since grinding could either diminish the signal to noise ratio and also cause a
change of the shape of the ESR spectrum or induce other ESR signals [25].
6.1.2 Shells and stones
Remove pieces of suitable size (about 50 mg to 100 mg, e.g. 3,0 mm to 3,5 mm in diameter) from the shells
or stones of the foodstuff, e.g. using a scalpel or pincers. Drying [e.g. in a freeze-dryer or at approximately
40 °C in a laboratory vacuum oven (5.4)] is usually not necessary in the case of nutshells but
recommended for pips and kernels of fruits.
6.1.3 Spices
For example, use about 150 mg to 200 mg of the spice sample. Drying (e.g. in a freeze-dryer or at
approximately 40 °C in a laboratory vacuum oven (5.4)) is usually not necessary.
g-value calculation unit including frequency counter magnetic field probe (magnetic resonance Teslameter) or
any other built in g-value calculation unit.
2
Suprasil is an example of a product available commercially. This information is given for the convenience
of users of this Standard and does not constitute an endorsement of CEN or CENELEC of this product.
6.1.4 Strawberries
Strawberry samples should be measured immediately after receipt. Otherwise store the samples at
approximately −18 °C until analysis.
For ESR measurement about 200 mg of seeds (achenes) of strawberries are needed. These can be gained
usually from about 80 g of strawberries.
For separation of the small seeds from the main fruit body either peel off the skin (recommendation: in
frozen state) or use the whole fruit (without stalks and leaves). Homogenize the strawberries in an
electric blender (5.5). Add 500 ml of water to the fruit pulp and s
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