Cereals and cereal products - Sampling studies (ISO/TR 29263:2021)

This document presents the description and the results of the three studies conducted by United Kingdom, France and Germany related to grain sampling in order to define a harmonized sampling protocol for official controls.
These results had been used to draft ISO 24333.

Getreide und Getreideerzeugnisse - Probenahmestudien (ISO/TR 29263:2021)

Céréales et produits céréaliers - Études sur l'échantillonnage (ISO/TR 29263:2021)

Le présent document détaille et expose les résultats des trois études sur l’échantillonnage des céréales menées par le Royaume-Uni, la France et l’Allemagne, dans le but de définir un protocole d’échantillonnage harmonisé pour les contrôles officiels.
Ces résultats ont été utilisés pour élaborer l’ISO 24333.

Žito in žitni proizvodi - Študije vzorčenja (ISO/TR 29263:2021)

General Information

Status
Published
Publication Date
27-Jul-2021
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Start Date
28-Jul-2021
Due Date
19-Jun-2021
Completion Date
28-Jul-2021

Buy Standard

Technical report
TP CEN ISO/TR 29263:2021 - BARVE
English language
107 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TP CEN ISO/TR 29263:2021
01-september-2021
Žito in žitni proizvodi - Študije vzorčenja (ISO/TR 29263:2021)
Cereals and cereal products - Sampling studies (ISO/TR 29263:2021)
Getreide und Getreideerzeugnisse - Probenahmestudien (ISO/TR 29263:2021)
Céréales et produits céréaliers - Études sur l'échantillonnage (ISO/TR 29263:2021)
Ta slovenski standard je istoveten z: CEN ISO/TR 29263:2021
ICS:
67.060 Žita, stročnice in proizvodi iz Cereals, pulses and derived
njih products
SIST-TP CEN ISO/TR 29263:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST-TP CEN ISO/TR 29263:2021

---------------------- Page: 2 ----------------------
SIST-TP CEN ISO/TR 29263:2021


CEN ISO/TR 29263
TECHNICAL REPORT

RAPPORT TECHNIQUE

July 2021
TECHNISCHER BERICHT
ICS 67.060
English Version

Cereals and cereal products - Sampling studies (ISO/TR
29263:2021)
Céréales et produits céréaliers - Études sur Getreide und Getreideerzeugnisse -
l'échantillonnage (ISO/TR 29263:2021) Probenahmestudien (ISO/TR 29263:2021)


This Technical Report was approved by CEN on 21 June 2021. It has been drawn up by the Technical Committee CEN/TC 338.

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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TR 29263:2021 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------
SIST-TP CEN ISO/TR 29263:2021
CEN ISO/TR 29263:2021 (E)
Contents Page
European foreword . 3

2

---------------------- Page: 4 ----------------------
SIST-TP CEN ISO/TR 29263:2021
CEN ISO/TR 29263:2021 (E)
European foreword
This document (CEN ISO/TR 29263:2021) has been prepared by Technical Committee ISO/TC 34 "Food
products" in collaboration with Technical Committee CEN/TC 338 “Cereal and cereal products” the
secretariat of which is held by AFNOR.
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.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN websites.
Endorsement notice
The text of ISO/TR 29263:2021 has been approved by CEN as CEN ISO/TR 29263:2021 without any
modification.

3

---------------------- Page: 5 ----------------------
SIST-TP CEN ISO/TR 29263:2021

---------------------- Page: 6 ----------------------
SIST-TP CEN ISO/TR 29263:2021
TECHNICAL ISO/TR
REPORT 29263
First edition
2021-07
Cereals and cereal products —
Sampling studies
Céréales et produits céréaliers — Études sur l'échantillonnage
Reference number
ISO/TR 29263:2021(E)
©
ISO 2021

---------------------- Page: 7 ----------------------
SIST-TP CEN ISO/TR 29263:2021
ISO/TR 29263:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 8 ----------------------
SIST-TP CEN ISO/TR 29263:2021
ISO/TR 29263:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Context . 1
5 Study n°1: extract from "Grain sampling and assessment: sampling grain in lorries"
– Project report n° 339” . 1
5.1 General . 1
5.2 Context . 1
5.3 Studies conducted and objectives. 3
5.4 Methodology . 3
5.4.1 Conducting tests . 3
5.4.2 Results and conclusions . . . 5
6 Study n°2: extract from "Sampling grain in static and flowing condition –
alternatives to the regulatory protocol" .19
6.1 General .19
6.2 Context .20
6.2.1 Regulatory aspect .20
6.2.2 Normative aspect .20
6.3 Studies conducted and objectives.20
6.3.1 Study A .20
6.3.2 Study B .21
6.4 Study A: silos and lorries of wheat and corn – Fusariotoxins and quality assessment .21
6.4.1 Organising field tests .21
6.4.2 Results and conclusions . .33
6.5 Study B : silos of corn – Fusariotoxins; flowing grains .48
6.5.1 Organising field tests .48
6.5.2 Results and conclusions . .49
7 Study n°3: extract from "Investigation of the distribution of deoxynivalenol and
ochratoxin a contamination within a 26-T truckload of wheat kernels" – Project report .90
7.1 Context .91
7.2 Methodology .91
7.2.1 Instruments for sampling and sample homogenization process .91
7.2.2 Reagents and materials .91
7.2.3 Sampling procedure .92
7.2.4 Sample comminution .93
7.3 Results and Discussion .93
7.3.1 Distribution of DON and OTA infected kernels within the lot .93
7.3.2 Sample comminution study for the dry milling process.95
7.4 Uncertainty comparison on the basis of number of incremental samples .95
7.5 Conclusions .97
Bibliography .98
© ISO 2021 – All rights reserved iii

---------------------- Page: 9 ----------------------
SIST-TP CEN ISO/TR 29263:2021
ISO/TR 29263:2021(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.
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 documents 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).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on 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 the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 4,
Cereals and pulses, in collaboration with the European Committee for Standardization (CEN) Technical
Committee CEN/TC 338, Cereal and cereal products, 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 2021 – All rights reserved

---------------------- Page: 10 ----------------------
SIST-TP CEN ISO/TR 29263:2021
ISO/TR 29263:2021(E)

Introduction
This document presents the results of three groups of studies which results have been used to elaborate
ISO 24333
These studies have been managed by United Kingdom in May 2003, by France in 2004-2005 for the first
one and 2006-2007 for the second one and Germany in 2008.
© ISO 2021 – All rights reserved v

---------------------- Page: 11 ----------------------
SIST-TP CEN ISO/TR 29263:2021

---------------------- Page: 12 ----------------------
SIST-TP CEN ISO/TR 29263:2021
TECHNICAL REPORT ISO/TR 29263:2021(E)
Cereals and cereal products — Sampling studies
1 Scope
This document presents the description and the results of the three studies conducted by United
Kingdom, France and Germany related to grain sampling in order to define a harmonized sampling
protocol for official controls.
These results had been used to draft ISO 24333.
2 Normative references
There are no normative references in this document.
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:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Context
European directives for official controls of some contaminants such as mycotoxins required methods
for sampling and analysis. In order to harmonize sampling procedures necessary for these analysis and
to determine the best way to prepare a homogenous and representative laboratory sample, studies had
been conducted by United Kingdom, France and Germany.
The results of these 3 studies are presented in this report.
5 Study n°1: extract from "Grain sampling and assessment: sampling grain in
lorries" – Project report n° 339”
5.1 General
By J. KNIGHT, R. WILKIN and J. RIVETT
Department of Environmental Science and Technology, Renewable Resources Assessment Group,
Imperial College of Science and Technology, Prince Consort Road, London SW7 2BB
This is the final report of a 13-month project that started in May 2003. The work was funded by HGCA
(project 2955).
5.2 Context
This two-year programme was made at the request of HGCA to improve and standardise grain sampling
and analysis across the UK cereals industry.
© ISO 2021 – All rights reserved 1

---------------------- Page: 13 ----------------------
SIST-TP CEN ISO/TR 29263:2021
ISO/TR 29263:2021(E)

The first phase of the programme was to develop and validate protocols suitable for collecting samples
of grain on UK farms at harvest time and to train farmers in their use. The second part was to examine
approaches to the collection of samples during storage and to compare the results obtained, wherever
possible, with data collected as the store was filled. During the course of earlier sampling work, there
was strong interest expressed in the mechanics and effectiveness of sampling loads of grain in lorries.
In addition, some of the work done during storage involved sampling grain as it left the store in lorries.
This showed up the limitations of some approaches to lorry sampling and highlighted the need for more
information. An assessment of lorry sampling was therefore, added and is reported here.
Almost all grain is sampled as it is delivered to end users to confirm its quality and to ensure that
contractual obligations are met. This sampling takes the form of collecting one or more samples from a
lorry-load on arrival. The equipment used and method of sampling varies between end users and there
are no data to show if these variations may cause bias in the representativeness of the sample and,
therefore, in the results of quality analysis.
The key aim of end-user sampling is to ensure that the quality of the grain is suitable for its intended
use. Therefore, sampling is done before the load is tipped and this limits access to the surface of the
load. This access is further constrained by food safety and HSE legislation that prevent the sampler
from walking on the load.
A limited assessment of the practicalities of sampling lorries was done in 1992 (HGCA Project
Report 79) in which the effects of method of sampling, number and position of sample points, the
methods of loading lorries were considered. The wheat sampled was low-grade feed material with a low
specific weight and a high level of fine material so was not representative of other grades. The results
suggested that loading lorries with a front loader or from a hopper had no effect on the distribution of
the quality characteristics within a load. Small differences were noted in the mean values for specific
weight between automatic sampling using a Samplex CS90 and a manual spear but overall variability
of the grain meant that these differences were not significant. There was significant variability in the
results obtained at individual points with either method, although this variability was random and not
associated with any part of the load. Fine material appeared to be very difficult to measure. At the time,
this work was undertaken there were no restrictions limiting access to the surface of the grain so that a
widely disbursed pattern of sampling points could be used with the manual sampling. The conclusions
from this work were that it was extremely unwise to base an assessment of lorry load of grain on a
single sample and that more work was needed to confirm the results and to assesses other grades of
grain. The aim of this project was to establish if there are any inherent problems with the sampling of
grain for the determination of quality characteristics in lorries at the point of intake and to establish
recommendations in the form of a protocol for the sampling of grain under these conditions.
Grain was sampled using automated systems (Samplex CS90) and manual spearing to see if the method
of sampling influenced the grain quality measurements. A key part of the process was to assess the
influence that the number of samples taken from each load had on the likely accuracy of the results.
Samples were collected at 4 different locations; on two occasions 10 lorries were sampled and on two
occasions 8 lorries were sampled. At three locations, CS90 samplers were used and 8 samples were
withdrawn from each load and at the other location samples were taken manually with a multi-
compartmented spear with 5 samples being taken from each lorry. A comparison of different ways
of sample handling was obtained by comparing the individual results from the 8 samples against an
analysis of samples withdrawn from a composite sample formed from 8 samples. The latter method
reflects more accurately the procedure followed at most stores.
Results indicated that there were no statistically significant differences between results from the
individual samples or from the composite samples. Monte Carlo simulation of the impacts of using 2, 3, 5
or 8 samples per load revealed that the greater the number of samples used the greater the reliability of
the result and the more likely it was to represent the true mean of the load. It was noted that automatic
sampling equipment can no longer sample the entire length of a trailer and this could cause problems
with obtaining the ideal sample. Manual sampling also had severe limitations due to the lack of safe
access for sampling of trailers.
A sampling protocol for lorries is presented which emphasises the need for 8 samples to be taken from
each load in order to get a good representation of the quality of the entire load.
2 © ISO 2021 – All rights reserved

---------------------- Page: 14 ----------------------
SIST-TP CEN ISO/TR 29263:2021
ISO/TR 29263:2021(E)

5.3 Studies conducted and objectives
The study was conducted to assess the effectiveness of different approaches to sampling loads of grain
in lorries.
The specific objectives were:
— To assess if the method of collecting samples influences grain quality measurement;
— To assess if the number and position of sampling points influences grain quality measurement;
— To provide guidelines for sampling lorries giving reliable information about grain quality.
5.4 Methodology
5.4.1 Conducting tests
5.4.1.1 Collection of data relating to current sampling practice
In November 2002 the HGCA circulated a questionnaire to commercial grain stores and end-users of
grain requesting information about their methods of analysis and methods of intake sampling. The
information that was collected was used to assist with the design of the assessment of lorry sampling.
5.4.1.2 Sample collection
5.4.1.2.1 Store 1
The work was done at a store specialising in the storage of malting barley. Lorries were loaded with
malting barley, variety Pearl, of a quality representative of that delivered to central storage from farms.
The lorries, all 28 t articulated units, were loaded with a front loader fitted with a 2 t bucket.
Ten loads were sampled over a 2-day period. Sampling was done using the store’s Samplex CS90
automated vacuum sampler. Initially, it had been expected to re-programme the CS90 to take 10
samples/load in a pre-set pattern. However, observation of the method of operation and sampling
pattern achieved by the CS90 suggested that there was no advantage in using more than the 8 points
provided by one of the standard sampler programmes.
During the setting up and initial testing of the CS90, the slide on the sample spear was opened to its
maximum to increase the sample size. The system was set to collect grain only during the withdrawal
as is recommended by the manufacturer for granular materials.
Each of the eight points was sampled three times. On the first occasion, individual samples were held
separately. During the second and third samplings, all samples were bulked into single batches. One of
these bulk samples was held as a composite sample and the other was used to provide samples of 1, 2
and 3 litres (small medium and large) collected at random with a 1-litre jug.
A small sub-sample from each of the individual samples was tested on the spot by store staff for
screenings and germinative capacity. Screenings were tested by sieving a 100 g sub-sample with
a motorised shaker fitted with a 2,25 mm mesh screen for 2 minutes. The germinative capacity was
tested using the standard tetrazolium test.
5.4.1.2.2 Store 2
Work was done at a commercial store during the normal out-loading of feed wheat. The lorries were
loaded from an on-floor bulk using a front-bucket loader and were sampled as they left the store. Normal
sampling practice was to collect a single spear sample/load using a manual, multi-compartmented
spear of about 1,7 m in length. Access to the load was via a small sampling platform that only allowed
samples to be taken from less than half the length of the loaded trailer and from only one side of the
load.
© ISO 2021 – All rights reserved 3

---------------------- Page: 15 ----------------------
SIST-TP CEN ISO/TR 29263:2021
ISO/TR 29263:2021(E)

For the purposes of this investigation, 5 sample points were used for each load and the lorry was moved
forward during the sampling process so that access to the whole length of the load could be obtained.
However, it was not practical to turn the lorry round to give access to both sides of the load. Manual
sampling meant that there was, inevitably, some variation in the exact location of the sample points
between loads. Three spear samples were collected at each point. The first was held as an individual
sample, the second bulked to form a composite sample and the third bulked to give a sample from which
three random samples (small, medium and large) could be taken without mixing.
Ten lorry loads were sampled over a two-day period.
5.4.1.2.3 Store 3
The assessments were made at a commercial store during the normal out-loading of milling wheat.
Samples were collected using a Samplex CS90 but without the automatic option. Therefore, the spear
had to be controlled manually by the operator and this meant that there was considerable variation in
the positioning of sample points between loads. A further constraint on sampling was that the CS90
was positioned at one end of the weighbridge thus limiting access to just one-half of the load. The slide
on the sampler was fully open and grain was collected only as the spear withdrew.
The lorries were loaded using a bucket loader from a 2 000 t batch of wheat stored on-floor. Only a
limited number of loads were dispatched each day and time constraints meant that only 8 loads were
sampled during this assessment.
Three samples were collected from 8 sample points in each load. The first was held as an individual
sample, the second bulked to form a composite sample and the third bulked to give a sample from
which three random samples (small, medium and large) could be taken without mixing. The 8 points
were arranged in a 3, 2, 3 pattern with the two samples being taken from the centre line and each row
of 3 taken down the sides of the load (see Figure 1). The location of the sampler and the position of the
lorry on the weighbridge meant that the samples always came from the front half of the load.
Figure 1 — Arrangement of sampling points used by CS90 sampler
Data was supplied by the storekeeper giving the store’s own assessment of the quality of the batch of
grain as measured when the store was filled.
5.4.1.2.4 Store 4
Loads of milling wheat delivered to a large flour mill were sampled with a Samplex automatic CS90.
This work was done some months after the earlier assessments and it was decided that the collection of
extra samples to make up composite batches was not justified. Eight samples were collected from eight
loads of wheat over a 10 d period. For technical reasons, the collection of samples had to be done by mill
staff so the exact details of the points sampled are not known.
5.4.1.3 Assessment of samples
Samples had to be transported to the testing laboratory and some additional delays occurred between
the collection and assessment of samples. However, samples that could not be analysed within 48 h
were stored in a freezer at -16 °C to minimise changes in the properties of the grain. These samples
were allowed to return to ambient temperature before testing. The exceptions to this were samples
collected from store 4.
4 © ISO 2021 – All rights reserved

---------------------- Page: 16 ----------------------
SIST-TP CEN ISO/TR 29263:2021
ISO/TR 29263:2021(E)

These were collected over a 10 d period and a further 4 d elapsed before the samples arrived for testing.
During this period, the samples were not held under controlled temperature conditions.
Individual samples were tested separately, as were the three different sizes of random sample. However,
in the case of the medium and large samples, these were divided by coning and quartering to give the
correct volume of grain for assessment. The composite samples were also mixed and then divided by
coning and quartering. Five sub-sample
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.