ISO 6658:2017
(Main)Sensory analysis — Methodology — General guidance
Sensory analysis — Methodology — General guidance
ISO 6658:2017 gives general guidance on the use of sensory analysis. It describes tests for the examination of foods and other products by sensory analysis, and includes some general information on the techniques to be used if statistical analysis of the results is required. Generally these tests are intended only for objective sensory analysis. However, if a test can be used for determining preference in hedonic test, this is indicated. A hedonic test aims to determine the acceptability of the products and/or to determine preferences among two or more products by the specified consumer population. The methods are effective for determining whether a perceptible preference exists (difference in degree of liking), or whether no perceptible preference exists (paired similarity test). General guidance for hedonic tests is given in ISO 11136.
Analyse sensorielle — Méthodologie — Lignes directrices générales
ISO 6658:2017 fournit des lignes directrices générales sur la méthodologie de l'analyse sensorielle. Il décrit des essais destinés à l'examen des produits alimentaires et d'autres produits par analyse sensorielle et donne des informations générales relatives aux techniques à utiliser si une analyse statistique des résultats est requise. En général, ces essais sont uniquement destinés à une analyse sensorielle objective. Toutefois, s'il est possible d'utiliser un essai pour déterminer la préférence au cours d'un essai hédonique, cela est précisé. Un essai hédonique vise à déterminer l'acceptabilité des produits et/ou à déterminer les préférences d'une population de consommateurs spécifique entre deux produits ou plus. Les méthodes sont efficaces pour déterminer s'il existe une préférence perceptible (différence dans le degré d'appréciation), ou s'il n'existe aucune préférence perceptible (essai de similitude par paires). Les lignes directrices générales pour les essais hédoniques sont données dans l'ISO 11136.
Senzorična analiza - Metodologija - Splošne smernice (ISO 6658:2017)
Ta dokument podaja splošne smernice za uporabo senzorične analize. Opisuje preskuse za pregledovanje živil in drugih proizvodov z uporabo senzorične analize ter vključuje nekaj splošnih informacij o tehnikah, ki se uporabljajo, če je treba izvesti statistično analizo rezultatov.
Ti preskusi so v splošnem namenjeni samo za objektivno senzorično analizo. Vendar če je preskus mogoče uporabiti za določevanje prednostnih izbir v hedoničnem preskusu, je to navedeno.
Namen hedoničnega preskusa je določiti sprejemljivost proizvodov in/ali prednostne izbire
med dvema ali več proizvodi s pomočjo določene skupine potrošnikov. Metode so učinkovite pri
določevanju, ali zaznavna prednostna izbira obstaja (razlika v stopnji všečnosti) ali
zaznavna prednostna izbira ne obstaja (preskus parne podobnosti). Splošno navodilo za hedonične preskuse je podano v
standardu ISO 11136.
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INTERNATIONAL ISO
STANDARD 6658
Third edition
2017-07
Sensory analysis — Methodology —
General guidance
Analyse sensorielle — Méthodologie — Lignes directrices générales
Reference number
ISO 6658:2017(E)
©
ISO 2017
---------------------- Page: 1 ----------------------
ISO 6658:2017(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved
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ISO 6658:2017(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General requirements . 1
4.1 Basic information . 1
4.2 Statement of objectives . 2
4.3 Choice of test . 2
4.4 Choosing and training assessors . 3
4.5 Material to be tested . . 3
4.6 Test room . 4
4.7 Planning and conduct of the test . 4
5 Test methods . 5
5.1 General . 5
5.2 Discrimination tests . 6
5.2.1 General. 6
5.2.2 Paired comparison test. 6
5.2.3 Triangle test . 7
5.2.4 Duo-trio test . 8
5.2.5 Two-out-of-five test . 8
5.2.6 “A — not A” test . 9
5.2.7 Tetrad test . 9
5.3 Use of scales and categories .10
5.3.1 General considerations .10
5.3.2 Interpretation of results .10
5.3.3 Classification .11
5.3.4 Grading .11
5.3.5 Ranking .11
5.3.6 Rating and scoring .12
5.4 Descriptive tests.12
5.4.1 General.12
5.4.2 Qualitative sensory profile .13
5.4.3 Quantitative descriptive profile .13
5.4.4 Consensus profile .15
5.4.5 Free-choice profile.15
5.4.6 Flash profile .16
5.4.7 Deviation from reference profile.16
5.4.8 Temporal dominance of sensations (TDS).17
6 Analysis of results.17
6.1 General .17
6.2 Discrimination tests .17
6.2.1 General.17
6.2.2 Paired comparison test (see ISO 5495) .18
6.2.3 Triangle test (see ISO 4120) .19
6.2.4 Duo-trio test (see ISO 10399) .19
6.2.5 Two-out-of-five test .19
6.2.6 “A — not A” test (see ISO 8588) .19
6.2.7 Tetrad test .19
6.2.8 Treatment of “no difference” responses in discrimination tests .19
6.2.9 Systematic effects .20
6.2.10 Sequential approach (see ISO 16820) .20
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ISO 6658:2017(E)
6.3 Tests using scales and categories .20
6.3.1 General.20
6.3.2 Classification .20
6.3.3 Grading (see ISO 4121) .20
6.3.4 Ranking (see ISO 8587) .20
6.3.5 Rating .21
6.3.6 Scoring .21
6.4 Analytical or descriptive tests .21
7 Test report .21
Annex A (informative) Statistical terms .23
Bibliography .25
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ISO 6658:2017(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: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 34, Food Products, Subcommittee SC 12,
Sensory analysis.
This third edition cancels and replaces the second edition (ISO 6658:2005), which has been technically
revised. The following changes have been made:
— the definition of “sensory analysis” was updated;
— a tetrad test was added to the discrimination tests as 5.2.7;
— the descriptive test in 5.4 was expanded by new methods;
— Clause 6 was updated;
— Table A.1 was deleted from Annex A;
— the Bibliography was updated and expanded.
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ISO 6658:2017(E)
Introduction
This document constitutes a general introduction to the methodology of sensory analysis and should be
read before undertaking the more detailed test procedures described in other International Standards.
It covers the general area of methodology and is intended to fulfil the following functions:
— to provide a brief background of the essential features of methods of sensory analysis for the user
of specific tests;
— to provide details of general requirements, procedures and interpretation of results common to all
or most tests;
— to provide sufficient guidance on requirements, procedures and interpretation of results for
the different specific tests to allow choice of the most appropriate procedure(s) for solution of a
particular problem.
It comprises three main aspects, covered in Clauses 4, 5 and 6.
It is essential that Clause 4 “General requirements” be read first. Clause 5 “Methods of test” describes,
in a general manner, all the main tests. Clause 6 is concerned with some general principles of data
collection and analysis of sensory data and also briefly covers general principles of statistical treatment
of the results.
vi © ISO 2017 – All rights reserved
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INTERNATIONAL STANDARD ISO 6658:2017(E)
Sensory analysis — Methodology — General guidance
WARNING — This document does not purport to address all of the safety problems, if any,
associated with its use. It is the responsibility of the user to establish appropriate safety and
health practices and to ensure compliance with any national regulatory conditions.
1 Scope
This document gives general guidance on the use of sensory analysis. It describes tests for the
examination of foods and other products by sensory analysis, and includes some general information
on the techniques to be used if statistical analysis of the results is required.
Generally these tests are intended only for objective sensory analysis. However, if a test can be used for
determining preference in hedonic test, this is indicated.
A hedonic test aims to determine the acceptability of the products and/or to determine preferences
among two or more products by the specified consumer population. The methods are effective for
determining whether a perceptible preference exists (difference in degree of liking), or whether no
perceptible preference exists (paired similarity test). General guidance for hedonic tests is given in
ISO 11136.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 5492, Sensory analysis — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5492 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
sensory analysis
science involved with the assessment of the organoleptic attributes of a product by the senses
4 General requirements
4.1 Basic information
This clause covers the general requirements common to all situations encountered in sensory analysis.
The information basic to these requirements is as follows.
a) The human response to one stimulus cannot be isolated from previous experiences or from other
sensory stimuli received from the environment. Nevertheless, influences arising from these two
sources can be controlled and the effect standardized.
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ISO 6658:2017(E)
b) Variability in sensory response is inherent in any group of people used for testing and is
unavoidable; this can arise from inconsistencies within an individual, and through physiological
and psychological differences between individuals. However, with training, such a group can show
highly consistent individual responses. Recognition of these factors is important in the analysis of
results.
c) Systematic biases in sensory experiments involving human response can result in misleading
data and incorrect interpretation that can be difficult to identify. The factors that can result in
bias should be identified and controlled as far as possible by appropriate experimental design and
conduct of the tests.
d) The validity of the conclusions drawn from the results is dependent upon the test used and the way
it is conducted, including the questions that have been asked.
4.2 Statement of objectives
There are three main types of objective, as follows:
a) those in which the aim of the test is to categorize, rank or describe the product(s);
b) those in which the aim is to distinguish between two or more products; here it is important to
distinguish between the need to know
i) if there is a difference at all,
ii) how great is the magnitude of the difference,
iii) the direction (or quality) of that difference,
iv) the influence of that difference, e.g. with regard to preference, or
v) if all or only part of a population is detecting a difference;
c) those in which reassurance is sought that products are sufficiently similar to be used
interchangeably.
In sensory analysis, a given problem frequently requires appreciable discussion or thought before an
appropriate test is selected. This is because the initial concept of the problem may require clarification.
4.3 Choice of test
The choice of appropriate test depends largely on the nature of the test objective, but also needs to take
account of factors associated with the product, the assessors, the test environment, and the desired
level of analytical precision and statistical confidence in the conclusions. The action that would occur
based on the outcome of the test should be determined in advance.
For each test, an attempt is made in Clause 5 to give guidance as to its relevance. Preliminary tests may
be necessary to confirm the applicability of a given test.
Because of sensory fatigue and the effects of adaptation, only a limited number of samples can be
assessed during a session, depending on the nature of the test and the type of product. Some of these
effects can be moderated by appropriate rinse procedures and recovery between samples.
While the use of control samples is essential in most cases, their use naturally limits the number of
samples that can be assessed during any given session.
The statistical plan should always be determined before starting the tests. This is especially
recommended if the number of samples to be evaluated requires more than one session. Details of
statistical plans should be selected from specialized texts. Whatever test method is used, the sequential
testing approach described in ISO 16820 should be considered whenever it is desirable to keep the
number of samples or the number of assessors to a minimum.
2 © ISO 2017 – All rights reserved
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ISO 6658:2017(E)
4.4 Choosing and training assessors
A sensory analysis panel constitutes a true “measuring instrument”, and consequently the results of
the analyses conducted depend on its members. The recruitment of persons willing to participate in a
panel, therefore, needs to be carried out with care and should be considered as a real investment, both
in time and financially. Management support in the organization is necessary if it is to be effective.
Sensory assessment may be made by three types of assessor: “sensory assessors”, “selected assessors”
or “expert sensory assessors”. Assessors can be “naive assessors” who do not have to meet any precise
criterion of selection or training, or people who have already taken part in some sensory tests (“initiated
assessors”). “Selected assessors” are assessors who have been selected and trained for the particular
sensory test. “Expert sensory assessors” are selected assessors who have been selected and trained
for a variety of sensory analysis methods and who are able to make consistent and repeatable sensory
assessments of products in one or several categories.
The selection and training methods to be employed depend on the tasks and methods that it is intended
to give to the “selected assessors”. Procedures for training assessors for descriptive tests are different
from those for training assessors in discrimination tests.
Detailed procedures and methods for selection and training of assessors are given in ISO 8586. It
should be noted that these methods sometimes only constitute a way of choosing the better candidates
amongst those who are available, rather than to satisfy predetermined criteria. Also, the selection
of assessors for their ability to discriminate and describe foods and other products is quite different
from that used for preference tests. The former tasks require selection and training, whereas the latter
requires only that the panel be representative of a specified sector of the population, for example, a
group of consumers.
If a selection procedure is to be carried out, some important criteria for choosing assessors are as
follows:
a) general ability to perform the specific sensory task;
b) availability with respect to normal employment;
c) motivation (willingness and interest);
d) good health (including the absence of specific allergies or treatment with medications) and good
dental and general hygienic condition.
The performance of “selected assessors” and “expert sensory assessors” should be monitored regularly
to ensure that the criteria by which they were initially selected continue to be met (see ISO 11132).
4.5 Material to be tested
The nature of the product to be tested determines the experimental protocol of the test, and may
also have an influence on the type of test that is required to satisfy the test objectives. For example,
a protocol in which foods are to be consumed hot will need to take into account the cooling rate of
the product and the likely effect on sensory attributes, and the changes in sensory attributes that may
occur in keeping the product hot prior to testing.
Methods of preparation and presentation of samples should be appropriate for the product and to the
problem concerned.
EXAMPLE 1 A product that is normally consumed hot is prepared in the usual manner and tested hot; however,
elevated temperatures can be used in some circumstances to increase the ease with which some flavours can be
evaluated.
EXAMPLE 2 A product that is normally consumed in discrete pieces is not homogenized in order to retain
textural characteristics. Care is needed, however, to ensure maximum uniformity between sub-samples for each
assessor; this includes similar portion size and uniformity of composition.
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ISO 6658:2017(E)
General principles for product sampling (in accordance with International Standards relating to
the product under test) should be applied for test samples. In all cases, documentation of sample
identification codes or lot numbers is necessary. Valid conclusions can be drawn for a product as a
whole only if the samples tested are representative.
Carriers may sometimes be used for tests relating to the evaluation of products for which direct tasting
is not feasible (see ISO 5497), for example food ingredients.
Lighting conditions should be specified when appearance is being assessed. When the test concerns
only differences in flavour, the effect of colour differences may be partially masked by the use of lighting
conditions that minimize the colour difference.
Containers should be chosen so as not to affect the test or the product. These may include washable
ceramic or glass containers, or disposable plastic or paper containers, but shall not transfer chemical
materials that could result in taint. In particular, washable containers should be washed only in odour-
and taint-free detergents and rinsed in water, and polymeric and paper containers, including insulated
containers used for hot or cold samples, should be odour- and taint-free.
Palate cleansers may be used by the assessors between samples and between sessions, but care should
be taken to ensure that they do not influence the flavour of products to be assessed. Still and carbonated
water and bland foods (for example, unsalted crackers) may be used between samples and between
sessions. Checks on the water supply are desirable to ensure that it is bland and safe to consume. For
particular purposes, deionized water, glass-distilled water, low mineral content spring water, carbon-
filtered water or boiled tap water may be used, but it shall be noted that they are likely to have different
flavours.
4.6 Test room
Sensory analysis shall be conducted in a dedicated test room (see ISO 8589 for guidance). The aim shall
be to create for each assessor a separate environment with minimum distraction, so that each assessor
can quickly adjust to the nature of the new task(s). Extraneous activities, including preparation of the
samples, should not be allowed during the tests, as these can lead to biased results. The room should be
at a comfortable temperature and should be ventilated with odour-free air; limited airflow is desirable
to avoid excessive temperature fluctuations. Persistent odours, such as tobacco or cosmetics, shall not
be allowed to contaminate the environment of the test room.
Sound should be restricted. A low background noise is usually more tolerable than a fluctuating level
of noise. Conversation is more distracting than background noise. Interruptions cause the greatest
distraction.
It is usually helpful to have control over both the colour and the intensity of the lighting, although
coloured lights rarely succeed in completely masking differences in appearance.
Surfaces shall be non-absorbent and designed to facilitate a high standard
...
SLOVENSKI STANDARD
SIST ISO 6658:2018
01-oktober-2018
1DGRPHãþD
SIST ISO 6658:2011
6HQ]RULþQDDQDOL]D0HWRGRORJLMD6SORãQHVPHUQLFH ,62
Sensory analysis -- Methodology -- General guidance
Analyse sensorielle -- Méthodologie -- Lignes directrices générales
Ta slovenski standard je istoveten z: ISO 6658:2017
ICS:
67.240 6HQ]RULþQDDQDOL]D Sensory analysis
SIST ISO 6658:2018 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST ISO 6658:2018
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SIST ISO 6658:2018
INTERNATIONAL ISO
STANDARD 6658
Third edition
2017-07
Sensory analysis — Methodology —
General guidance
Analyse sensorielle — Méthodologie — Lignes directrices générales
Reference number
ISO 6658:2017(E)
©
ISO 2017
---------------------- Page: 3 ----------------------
SIST ISO 6658:2018
ISO 6658:2017(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 6658:2018
ISO 6658:2017(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General requirements . 1
4.1 Basic information . 1
4.2 Statement of objectives . 2
4.3 Choice of test . 2
4.4 Choosing and training assessors . 3
4.5 Material to be tested . . 3
4.6 Test room . 4
4.7 Planning and conduct of the test . 4
5 Test methods . 5
5.1 General . 5
5.2 Discrimination tests . 6
5.2.1 General. 6
5.2.2 Paired comparison test. 6
5.2.3 Triangle test . 7
5.2.4 Duo-trio test . 8
5.2.5 Two-out-of-five test . 8
5.2.6 “A — not A” test . 9
5.2.7 Tetrad test . 9
5.3 Use of scales and categories .10
5.3.1 General considerations .10
5.3.2 Interpretation of results .10
5.3.3 Classification .11
5.3.4 Grading .11
5.3.5 Ranking .11
5.3.6 Rating and scoring .12
5.4 Descriptive tests.12
5.4.1 General.12
5.4.2 Qualitative sensory profile .13
5.4.3 Quantitative descriptive profile .13
5.4.4 Consensus profile .15
5.4.5 Free-choice profile.15
5.4.6 Flash profile .16
5.4.7 Deviation from reference profile.16
5.4.8 Temporal dominance of sensations (TDS).17
6 Analysis of results.17
6.1 General .17
6.2 Discrimination tests .17
6.2.1 General.17
6.2.2 Paired comparison test (see ISO 5495) .18
6.2.3 Triangle test (see ISO 4120) .19
6.2.4 Duo-trio test (see ISO 10399) .19
6.2.5 Two-out-of-five test .19
6.2.6 “A — not A” test (see ISO 8588) .19
6.2.7 Tetrad test .19
6.2.8 Treatment of “no difference” responses in discrimination tests .19
6.2.9 Systematic effects .20
6.2.10 Sequential approach (see ISO 16820) .20
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SIST ISO 6658:2018
ISO 6658:2017(E)
6.3 Tests using scales and categories .20
6.3.1 General.20
6.3.2 Classification .20
6.3.3 Grading (see ISO 4121) .20
6.3.4 Ranking (see ISO 8587) .20
6.3.5 Rating .21
6.3.6 Scoring .21
6.4 Analytical or descriptive tests .21
7 Test report .21
Annex A (informative) Statistical terms .23
Bibliography .25
iv © ISO 2017 – All rights reserved
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SIST ISO 6658:2018
ISO 6658:2017(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: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 34, Food Products, Subcommittee SC 12,
Sensory analysis.
This third edition cancels and replaces the second edition (ISO 6658:2005), which has been technically
revised. The following changes have been made:
— the definition of “sensory analysis” was updated;
— a tetrad test was added to the discrimination tests as 5.2.7;
— the descriptive test in 5.4 was expanded by new methods;
— Clause 6 was updated;
— Table A.1 was deleted from Annex A;
— the Bibliography was updated and expanded.
© ISO 2017 – All rights reserved v
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SIST ISO 6658:2018
ISO 6658:2017(E)
Introduction
This document constitutes a general introduction to the methodology of sensory analysis and should be
read before undertaking the more detailed test procedures described in other International Standards.
It covers the general area of methodology and is intended to fulfil the following functions:
— to provide a brief background of the essential features of methods of sensory analysis for the user
of specific tests;
— to provide details of general requirements, procedures and interpretation of results common to all
or most tests;
— to provide sufficient guidance on requirements, procedures and interpretation of results for
the different specific tests to allow choice of the most appropriate procedure(s) for solution of a
particular problem.
It comprises three main aspects, covered in Clauses 4, 5 and 6.
It is essential that Clause 4 “General requirements” be read first. Clause 5 “Methods of test” describes,
in a general manner, all the main tests. Clause 6 is concerned with some general principles of data
collection and analysis of sensory data and also briefly covers general principles of statistical treatment
of the results.
vi © ISO 2017 – All rights reserved
---------------------- Page: 8 ----------------------
SIST ISO 6658:2018
INTERNATIONAL STANDARD ISO 6658:2017(E)
Sensory analysis — Methodology — General guidance
WARNING — This document does not purport to address all of the safety problems, if any,
associated with its use. It is the responsibility of the user to establish appropriate safety and
health practices and to ensure compliance with any national regulatory conditions.
1 Scope
This document gives general guidance on the use of sensory analysis. It describes tests for the
examination of foods and other products by sensory analysis, and includes some general information
on the techniques to be used if statistical analysis of the results is required.
Generally these tests are intended only for objective sensory analysis. However, if a test can be used for
determining preference in hedonic test, this is indicated.
A hedonic test aims to determine the acceptability of the products and/or to determine preferences
among two or more products by the specified consumer population. The methods are effective for
determining whether a perceptible preference exists (difference in degree of liking), or whether no
perceptible preference exists (paired similarity test). General guidance for hedonic tests is given in
ISO 11136.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 5492, Sensory analysis — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5492 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
sensory analysis
science involved with the assessment of the organoleptic attributes of a product by the senses
4 General requirements
4.1 Basic information
This clause covers the general requirements common to all situations encountered in sensory analysis.
The information basic to these requirements is as follows.
a) The human response to one stimulus cannot be isolated from previous experiences or from other
sensory stimuli received from the environment. Nevertheless, influences arising from these two
sources can be controlled and the effect standardized.
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b) Variability in sensory response is inherent in any group of people used for testing and is
unavoidable; this can arise from inconsistencies within an individual, and through physiological
and psychological differences between individuals. However, with training, such a group can show
highly consistent individual responses. Recognition of these factors is important in the analysis of
results.
c) Systematic biases in sensory experiments involving human response can result in misleading
data and incorrect interpretation that can be difficult to identify. The factors that can result in
bias should be identified and controlled as far as possible by appropriate experimental design and
conduct of the tests.
d) The validity of the conclusions drawn from the results is dependent upon the test used and the way
it is conducted, including the questions that have been asked.
4.2 Statement of objectives
There are three main types of objective, as follows:
a) those in which the aim of the test is to categorize, rank or describe the product(s);
b) those in which the aim is to distinguish between two or more products; here it is important to
distinguish between the need to know
i) if there is a difference at all,
ii) how great is the magnitude of the difference,
iii) the direction (or quality) of that difference,
iv) the influence of that difference, e.g. with regard to preference, or
v) if all or only part of a population is detecting a difference;
c) those in which reassurance is sought that products are sufficiently similar to be used
interchangeably.
In sensory analysis, a given problem frequently requires appreciable discussion or thought before an
appropriate test is selected. This is because the initial concept of the problem may require clarification.
4.3 Choice of test
The choice of appropriate test depends largely on the nature of the test objective, but also needs to take
account of factors associated with the product, the assessors, the test environment, and the desired
level of analytical precision and statistical confidence in the conclusions. The action that would occur
based on the outcome of the test should be determined in advance.
For each test, an attempt is made in Clause 5 to give guidance as to its relevance. Preliminary tests may
be necessary to confirm the applicability of a given test.
Because of sensory fatigue and the effects of adaptation, only a limited number of samples can be
assessed during a session, depending on the nature of the test and the type of product. Some of these
effects can be moderated by appropriate rinse procedures and recovery between samples.
While the use of control samples is essential in most cases, their use naturally limits the number of
samples that can be assessed during any given session.
The statistical plan should always be determined before starting the tests. This is especially
recommended if the number of samples to be evaluated requires more than one session. Details of
statistical plans should be selected from specialized texts. Whatever test method is used, the sequential
testing approach described in ISO 16820 should be considered whenever it is desirable to keep the
number of samples or the number of assessors to a minimum.
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4.4 Choosing and training assessors
A sensory analysis panel constitutes a true “measuring instrument”, and consequently the results of
the analyses conducted depend on its members. The recruitment of persons willing to participate in a
panel, therefore, needs to be carried out with care and should be considered as a real investment, both
in time and financially. Management support in the organization is necessary if it is to be effective.
Sensory assessment may be made by three types of assessor: “sensory assessors”, “selected assessors”
or “expert sensory assessors”. Assessors can be “naive assessors” who do not have to meet any precise
criterion of selection or training, or people who have already taken part in some sensory tests (“initiated
assessors”). “Selected assessors” are assessors who have been selected and trained for the particular
sensory test. “Expert sensory assessors” are selected assessors who have been selected and trained
for a variety of sensory analysis methods and who are able to make consistent and repeatable sensory
assessments of products in one or several categories.
The selection and training methods to be employed depend on the tasks and methods that it is intended
to give to the “selected assessors”. Procedures for training assessors for descriptive tests are different
from those for training assessors in discrimination tests.
Detailed procedures and methods for selection and training of assessors are given in ISO 8586. It
should be noted that these methods sometimes only constitute a way of choosing the better candidates
amongst those who are available, rather than to satisfy predetermined criteria. Also, the selection
of assessors for their ability to discriminate and describe foods and other products is quite different
from that used for preference tests. The former tasks require selection and training, whereas the latter
requires only that the panel be representative of a specified sector of the population, for example, a
group of consumers.
If a selection procedure is to be carried out, some important criteria for choosing assessors are as
follows:
a) general ability to perform the specific sensory task;
b) availability with respect to normal employment;
c) motivation (willingness and interest);
d) good health (including the absence of specific allergies or treatment with medications) and good
dental and general hygienic condition.
The performance of “selected assessors” and “expert sensory assessors” should be monitored regularly
to ensure that the criteria by which they were initially selected continue to be met (see ISO 11132).
4.5 Material to be tested
The nature of the product to be tested determines the experimental protocol of the test, and may
also have an influence on the type of test that is required to satisfy the test objectives. For example,
a protocol in which foods are to be consumed hot will need to take into account the cooling rate of
the product and the likely effect on sensory attributes, and the changes in sensory attributes that may
occur in keeping the product hot prior to testing.
Methods of preparation and presentation of samples should be appropriate for the product and to the
problem concerned.
EXAMPLE 1 A product that is normally consumed hot is prepared in the usual manner and tested hot; however,
elevated temperatures can be used in some circumstances to increase the ease with which some flavours can be
evaluated.
EXAMPLE 2 A product that is normally consumed in discrete pieces is not homogenized in order to retain
textural characteristics. Care is needed, however, to ensure maximum uniformity between sub-samples for each
assessor; this includes similar portion size and uniformity of composition.
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General principles for product sampling (in accordance with International Standards relating to
the product under test) should be applied for test samples. In all cases, documentation of sample
identification codes or lot numbers is necessary. Valid conclusions can be drawn for a product as a
whole only if the samples tested are representative.
Carriers may sometimes be used for tests relating to the evaluation of products for which direct tasting
is not feasible (see ISO 5497), for example food ingredients.
Lighting conditions should be specified when appearance is being assessed. When the test concerns
only differences in flavour, the effect of colour differences may be partially masked by the use of lighting
conditions that minimize the colour difference.
Containers should be chosen so as not to affect the test or the product. These may include washable
ceramic or glass containers, or disposable plastic or paper containers, but shall not transfer chemical
materials that could result in taint. In particular, washable containers should be washed only in odour-
and taint-free detergents and rinsed in water, and polymeric and paper containers, including insulated
containers used for hot or cold samples, should be odour- and taint-free.
Palate cleansers may be used by the assessors between samples and between sessions, but care should
be taken to ensure that they do not influence the flavour of products to be assessed. Still and carbonated
water and bland foods (for example, unsalted crackers) may be used between samples and between
sessions. Checks on the water supply are desirable to ensure that it is bland and safe to consume. For
particular purposes, deionized water, glass-distilled water, low mineral content spring water, carbon-
filtered water or boiled tap water may be used, but it shall be noted that they are likely to have different
flavours.
4.6 Test room
Sensory analysis shall be conducted in a dedicated test room (see ISO 8589 for guidance). The aim shall
be to create for each assessor a separate environment with minimum distraction, so that each assessor
can quickly adjust to the nature of the new task(s). Extraneous activities, including preparation of the
...
NORME ISO
INTERNATIONALE 6658
Troisième édition
2017-07
Analyse sensorielle — Méthodologie
— Lignes directrices générales
Sensory analysis — Methodology — General guidance
Numéro de référence
ISO 6658:2017(F)
©
ISO 2017
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ISO 6658:2017(F)
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2017, Publié en Suisse
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ISO 6658:2017(F)
Sommaire Page
Avant-propos .v
Introduction .vi
1 Domaine d’application . 1
2 Références normatives . 1
3 Termes et définitions . 1
4 Exigences générales . 2
4.1 Informations de base . 2
4.2 Objectifs . 2
4.3 Choix de l’essai . 2
4.4 Choix et entraînement des sujets . 3
4.5 Produit à soumettre à l’essai . 4
4.6 Local d’essai . 4
4.7 Planification et conduite de l’essai . 5
5 Méthodes d’essai . 6
5.1 Généralités . 6
5.2 Essais de discrimination . 6
5.2.1 Généralités . 6
5.2.2 Essai de comparaison par paires . 7
5.2.3 Essai triangulaire . 7
5.2.4 Essai duo-trio . 8
5.2.5 Essai 2 sur 5 . 9
5.2.6 Essai «A» ou «non A». 9
5.2.7 Essai tétrade .10
5.3 Essais utilisant des échelles et des catégories .10
5.3.1 Aspects généraux à prendre en compte .10
5.3.2 Interprétation des résultats .11
5.3.3 Catégorisation .12
5.3.4 Classification .12
5.3.5 Classement par rang .12
5.3.6 Cotation ou notation .13
5.4 Essais descriptifs .13
5.4.1 Généralités .13
5.4.2 Profil sensoriel qualitatif .14
5.4.3 Profil sensoriel quantitatif.14
5.4.4 Profil par consensus.16
5.4.5 Profil libre choix .16
5.4.6 Profil flash .17
5.4.7 Profil par rapport à une référence .17
5.4.8 Dominance temporelle des sensations (DTS) .18
6 Analyse des résultats .18
6.1 Généralités .18
6.2 Essais de discrimination .19
6.2.1 Généralités .19
6.2.2 Essai de comparaison par paires (voir l’ISO 5495) .19
6.2.3 Essai triangulaire (voir l’ISO 4120) .20
6.2.4 Essai duo-trio (voir l’ISO 10399) .20
6.2.5 Essai 2 sur 5 .20
6.2.6 Essai «A» ou «non A» (voir l’ISO 8588) .20
6.2.7 Essai tétrade .21
6.2.8 Traitement des réponses «aucune différence» dans les essais
de discrimination .21
6.2.9 Effets systématiques .21
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ISO 6658:2017(F)
6.2.10 Approche séquentielle (voir l’ISO 16820) .21
6.3 Essais utilisant des échelles et des catégories .21
6.3.1 Généralités .21
6.3.2 Catégorisation .21
6.3.3 Classification (voir l’ISO 4121) .22
6.3.4 Classement par rangs (voir l’ISO 8587) .22
6.3.5 Essai de cotation .22
6.3.6 Essai de notation .22
6.4 Essais analytiques ou descriptifs .22
7 Rapport d’essai .22
Annexe A (informative) Termes statistiques .24
Bibliographie .26
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ISO 6658:2017(F)
Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes
nationaux de normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est
en général confiée aux comités techniques de l’ISO. Chaque comité membre intéressé par une étude
a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l’ISO participent également aux travaux.
L’ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents
critères d’approbation requis pour les différents types de documents ISO. Le présent document a été
rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir www
.iso .org/ directives).
L’attention est appelée sur le fait que certains des éléments du présent document peuvent faire l’objet de
droits de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable
de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant
les références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de
l’élaboration du document sont indiqués dans l’Introduction et/ou dans la liste des déclarations de
brevets reçues par l’ISO (voir www .iso .org/ brevets).
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l’ISO liés à l’évaluation de la conformité, ou pour toute information au sujet de l’adhésion
de l’ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles
techniques au commerce (OTC), voir le lien suivant: w w w . i s o .org/ iso/ fr/ avant -propos .html.
Le présent document a été élaboré par le Comité Technique ISO/TC 34, Produits alimentaires, sous-
comité SC 12, Analyse sensorielle.
Cette troisième édition annule et remplace la deuxième édition (ISO 6658:2005), qui a fait l’objet d’une
révision technique. Les modifications suivantes ont été apportées:
— la définition de «l’analyse sensorielle» a été révisée;
— un essai tétrade a été ajouté aux essais de discrimination, au 5.2.7;
— de nouvelles méthodes d’essai descriptif ont été ajoutées en 5.4;
— l’Article 6 a été révisé;
— le Tableau A.1 a été supprimé de l’Annexe A;
— la Bibliographie a été mise à jour et étendue.
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ISO 6658:2017(F)
Introduction
Le présent document constitue une introduction générale à la méthodologie de l’analyse sensorielle et il
convient de la lire avant d’appliquer les méthodes d’essai plus détaillées décrites dans d’autres Normes
internationales. Il traite du domaine général de la méthodologie et il est destiné à remplir les fonctions
suivantes:
— fournir à l’utilisateur d’essais spécifiques un bref exposé général sur les caractéristiques essentielles
des méthodes d’analyse sensorielle;
— fournir des détails sur les exigences générales, les modes opératoires et l’interprétation des résultats
communs à tous les essais ou à la plupart d’entre eux;
— constituer un guide suffisant relatif aux exigences, aux modes opératoires et à l’interprétation des
résultats des différents essais spécifiques, afin de permettre de choisir le ou les modes opératoires
les plus appropriés à la résolution d’un problème particulier.
Il comprend trois parties principales, faisant l’objet des Articles 4, 5 et 6.
Il est indispensable de lire en premier l’Article 4 («Exigences générales»). L’Article 5 («Méthodes d’essai»)
décrit les principaux essais d’une manière générale. L’Article 6 traite de certains principes généraux
relatifs à la collecte et à l’analyse de données sensorielles et aborde aussi brièvement les principes
généraux du traitement statistique des résultats.
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NORME INTERNATIONALE ISO 6658:2017(F)
Analyse sensorielle — Méthodologie — Lignes directrices
générales
AVERTISSEMENT — Le présent document n’a pas pour but de traiter les problèmes de sécurité
qui peuvent être liés à son utilisation. Il est de la responsabilité de l’utilisateur d’établir des
pratiques appropriées de sécurité, de protection de la santé et de garantir la conformité vis-à-
vis des réglementations nationales en vigueur.
1 Domaine d’application
Le présent document fournit des lignes directrices générales sur la méthodologie de l’analyse
sensorielle. Il décrit des essais destinés à l’examen des produits alimentaires et d’autres produits
par analyse sensorielle et donne des informations générales relatives aux techniques à utiliser si une
analyse statistique des résultats est requise.
En général, ces essais sont uniquement destinés à une analyse sensorielle objective. Toutefois, s’il est
possible d’utiliser un essai pour déterminer la préférence au cours d’un essai hédonique, cela est précisé.
Un essai hédonique vise à déterminer l’acceptabilité des produits et/ou à déterminer les préférences
d’une population de consommateurs spécifique entre deux produits ou plus. Les méthodes sont efficaces
pour déterminer s’il existe une préférence perceptible (différence dans le degré d’appréciation), ou s’il
n’existe aucune préférence perceptible (essai de similitude par paires). Les lignes directrices générales
pour les essais hédoniques sont données dans l’ISO 11136.
2 Références normatives
Les documents ci-après, dans leur intégralité ou non, sont des références normatives indispensables à
l’application du présent document. Pour les références datées, seule l’édition citée s’applique. Pour les
références non datées, la dernière édition du document de référence s’applique (y compris les éventuels
amendements).
ISO 5492, Analyse sensorielle — Vocabulaire
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions donnés dans l’ISO 5492 ainsi que les
suivants s’appliquent.
L’ISO et l’IEC mettent à jour les bases de données terminologiques utilisées en normalisation aux
adresses suivantes:
— IEC Electropedia: accessible sur http:// www .electropedia .org/
— ISO Online browsing platform: accessible sur http:// www .iso .org/ obp
3.1
analyse sensorielle
science relative à l’examen des propriétés organoleptiques d’un produit par les organes des sens
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ISO 6658:2017(F)
4 Exigences générales
4.1 Informations de base
Le présent article traite des exigences générales communes à toutes les situations rencontrées lors
d’analyses sensorielles et dont les principes de base sont les suivants.
a) La réponse humaine à un stimulus ne peut être isolée d’expériences précédentes ou des autres
stimuli sensoriels provenant de l’environnement. Néanmoins, l’influence de ces deux facteurs peut
être contrôlée et ses effets pris en compte.
b) La variabilité de la réponse sensorielle est inhérente à tout groupe de personnes utilisé pour les
essais et elle est inévitable; elle peut provenir d’incohérences propres à un individu et de différences
physiologiques et psychologiques entre les individus. Toutefois, avec de l’entraînement, un tel
groupe de sujets peut donner des réponses individuelles très homogènes. L’identification de ces
facteurs est importante lors de l’analyse des résultats.
c) Des biais systématiques lors d’expériences sensorielles impliquant une réponse humaine peuvent
aboutir à des données fausses et à une interprétation incorrecte qu’il peut être difficile d’identifier.
Il convient d’identifier les facteurs susceptibles d’aboutir à des biais et de les contrôler, dans toute
la mesure du possible, en concevant et en conduisant les essais de manière appropriée.
d) La validité des conclusions tirées des résultats dépend de l’essai utilisé et de la façon dont il a été
conduit, y compris le choix des questions posées.
4.2 Objectifs
Trois principaux types d’objectifs sont exposés:
a) ceux pour lesquels le but de l’essai est de classer par catégorie ou par rang, ou de décrire le(s)
produit(s);
b) ceux dont le but est de différencier deux produits ou plus; il est important ici de faire la distinction
entre la nécessité de savoir:
i) s’il existe bien une différence;
ii) quelle est l’ampleur de la différence;
iii) quel est le sens (ou la nature) de la différence;
iv) quelle est l’influence de cette différence (par exemple sur la préférence);
v) si la totalité ou seulement une partie de la population détecte une différence;
c) ceux dont le but est de vérifier que les produits sont suffisamment similaires pour être utilisés de
façon interchangeable.
En analyse sensorielle, le problème donné nécessite fréquemment une discussion ou une réflexion
sérieuse avant de choisir un essai approprié. Cela est dû au fait que le concept initial du problème peut
nécessiter d’être clarifié.
4.3 Choix de l’essai
Le choix d’un essai approprié dépend en grande partie de l’objectif de l’essai, mais nécessite également
la prise en compte de facteurs liés au produit, aux sujets, à l’environnement d’essai ainsi qu’au niveau
recherché de précision analytique et de confiance statistique des conclusions. Il convient que l’action
pouvant découler des résultats des essais soit déterminée à l’avance.
Pour chaque essai, l’Article 5 s’efforce de donner des lignes directrices pour son domaine d’application.
Des essais préliminaires peuvent s’avérer nécessaires pour confirmer la faisabilité d’un essai donné.
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ISO 6658:2017(F)
Du fait de la fatigue sensorielle et de phénomènes d’adaptation, il n’est possible d’évaluer qu’un nombre
limité d’échantillons au cours d’une session, nombre variable selon la nature de l’essai et le type de
produit. Certains de ces effets peuvent être atténués par des modes opératoires appropriés de rinçage
et de repos entre échantillons.
Bien que des échantillons témoins soient nécessaires dans la plupart des cas, leur utilisation limite
naturellement le nombre d’échantillons qu’il est possible d’évaluer au cours d’une session donnée.
Il convient de toujours déterminer le plan d’expériences avant de commencer les essais. Cette
recommandation prévaut notamment si le nombre d’échantillons à évaluer nécessite plus d’une session.
Il convient de sélectionner les détails des plans d’expérience dans des ouvrages spécialisés. Quelle que
soit la méthode d’essai utilisée, chaque fois qu’il est souhaitable de minimiser le nombre d’échantillons
ou de sujets, il convient d’envisager l’approche séquentielle décrite dans l’ISO 16820.
4.4 Choix et entraînement des sujets
Un jury d’analyse sensorielle constitue un véritable «instrument de mesure» et, par conséquent, les
résultats des analyses effectuées dépendent de ses membres. Le recrutement de personnes désireuses
de faire partie d’un jury nécessite donc d’être effectué avec soin et il convient de le considérer comme
un réel investissement, à la fois en termes de temps et de coût. L’appui de la hiérarchie dans l’entreprise
est nécessaire pour qu’il soit accompli.
L’évaluation sensorielle peut être effectuée par trois types de personnes, à savoir des «sujets», des
«sujets qualifiés» ou des «sujets experts». Les sujets peuvent être des «sujets naïfs», n’ayant pas à
remplir de critère de sélection ou d’entraînement précis, ou encore des personnes ayant déjà pris
part à quelques essais sensoriels («sujets initiés»). Les «sujets qualifiés» sont des sujets qui ont été
sélectionnés et entraînés pour un essai sensoriel particulier. Les «sujets experts» sont des sujets
qualifiés qui ont été sélectionnés et entraînés pour différentes méthodes d’analyse sensorielle et qui
sont capables de réaliser des évaluations sensorielles homogènes et répétables de produits d’une ou
plusieurs catégories.
Les méthodes de sélection et d’entraînement à employer dépendent des tâches et des méthodes
destinées aux «sujets qualifiés». Les modes opératoires utilisés pour entraîner les sujets aux essais
descriptifs sont différents de ceux utilisés pour entraîner les sujets aux essais de discrimination.
Les modes opératoires et les méthodes de sélection et d’entraînement des sujets sont détaillés dans
l’ISO 8586. Il convient de noter que, parfois, ces méthodes ne font que constituer un moyen de choisir
les meilleurs candidats parmi ceux disponibles, plutôt que de satisfaire à des critères préétablis. Il
convient également de noter que la sélection de sujets pour leur aptitude à discriminer et à décrire les
produits alimentaires et d’autres produits est tout à fait différente de celle utilisée pour des essais de
préférence. Dans le premier cas, il est nécessaire d’effectuer une sélection et un entraînement alors que,
dans le second cas, il est uniquement demandé au jury d’être représentatif d’une certaine partie de la
population, par exemple un groupe de consommateurs ciblés.
Si un mode opératoire de sélection doit être mis en œuvre, plusieurs critères s’avèrent importants pour
le choix des sujets:
a) capacité générale à réaliser certaines tâches sensorielles spécifiques;
b) disponibilité par rapport au travail habituel;
c) motivation (volonté et intérêt);
d) bonne santé (y compris l’absence d’allergies particulières ou de traitement médicamenteux
particuliers) et bonnes conditions dentaires et d’hygiène générale.
Pour s’assurer que les «sujets qualifiés» et «sujets sensoriels experts» continuent de remplir les critères
sur lesquels ils ont été sélectionnés, il convient de contrôler régulièrement leurs performances (voir
ISO 11132).
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ISO 6658:2017(F)
4.5 Produit à soumettre à l’essai
La nature du produit à soumettre à essai détermine le protocole expérimental de l’essai et peut
également avoir une incidence sur le type d’essai requis pour répondre aux objectifs. Par exemple, un
protocole dans lequel les produits alimentaires doivent être consommés chauds nécessite de prendre
en compte la vitesse de refroidissement du produit et son effet probable sur les propriétés sensorielles,
ainsi que les changements des propriétés sensorielles qui peuvent se produire lorsque le produit est
maintenu chaud avant l’essai.
Il convient que les méthodes de préparation et de présentation des échantillons soient adaptées au
produit et au problème posé.
EXEMPLE 1 Un produit qui est normalement consommé chaud est préparé selon la technique habituelle et
dégusté chaud; toutefois, dans certaines circonstances, il est permis d’utiliser des températures élevées afin
d’augmenter la facilité avec laquelle certains goûts peuvent être évalués.
EXEMPLE 2 Il convient de ne pas homogénéiser un produit normalement consommé en morceaux distincts
afin de conserver les caractéristiques de sa texture. Il est cependant nécessaire de s’assurer qu’il y a une
uniformité maximale entre les sous-échantillons destinés à chacun des sujets, ce qui inclut des tailles de portions
similaires et une composition uniforme.
Il convient d’appliquer aux échantillons pour essai les principes généraux d’échantillonnage de produit
(conformément aux Normes internationales portant sur le produit soumis à l’essai). Dans tous les cas,
il est nécessaire d’indiquer les codes d’identification des échantillons ou les numéros de lots. Il n’est
possible de tirer des conclusions valables pour un produit dans son ensemble que si les échantillons
soumis à essai sont représentatifs.
Des supports peuvent parfois être utilisés dans les essais portant sur des produits pour lesquels
l’analyse directe n’est pas possible (voir l’ISO 5497), par exemple des ingrédients alimentaires.
Dans le cas de l’évaluation de l’aspect du produit, il convient de spécifier les conditions d’éclairage.
Lorsque l’essai porte uniquement sur les différences de goût, l’effet des différences de couleur peut être
partiellement masqué en utilisant des conditions d’éclairage qui réduisent au minimum la différence de
couleur.
Il convient de choisir les récipients de manière qu’ils n’affectent pas l’essai ou les produits. Il peut s’agir
de récipients en verre ou en céramique lavables ou de récipients en papier ou en plastique jetab
...
SLOVENSKI STANDARD
oSIST ISO 6658:2018
01-september-2018
6HQ]RULþQDDQDOL]D0HWRGRORJLMD6SORãQHVPHUQLFH ,62
Sensory analysis -- Methodology -- General guidance
Analyse sensorielle -- Méthodologie -- Lignes directrices générales
Ta slovenski standard je istoveten z: ISO 6658:2017
ICS:
67.240 6HQ]RULþQDDQDOL]D Sensory analysis
oSIST ISO 6658:2018 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST ISO 6658:2018
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oSIST ISO 6658:2018
INTERNATIONAL ISO
STANDARD 6658
Third edition
2017-07
Sensory analysis — Methodology —
General guidance
Analyse sensorielle — Méthodologie — Lignes directrices générales
Reference number
ISO 6658:2017(E)
©
ISO 2017
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oSIST ISO 6658:2018
ISO 6658:2017(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
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copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved
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oSIST ISO 6658:2018
ISO 6658:2017(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General requirements . 1
4.1 Basic information . 1
4.2 Statement of objectives . 2
4.3 Choice of test . 2
4.4 Choosing and training assessors . 3
4.5 Material to be tested . . 3
4.6 Test room . 4
4.7 Planning and conduct of the test . 4
5 Test methods . 5
5.1 General . 5
5.2 Discrimination tests . 6
5.2.1 General. 6
5.2.2 Paired comparison test. 6
5.2.3 Triangle test . 7
5.2.4 Duo-trio test . 8
5.2.5 Two-out-of-five test . 8
5.2.6 “A — not A” test . 9
5.2.7 Tetrad test . 9
5.3 Use of scales and categories .10
5.3.1 General considerations .10
5.3.2 Interpretation of results .10
5.3.3 Classification .11
5.3.4 Grading .11
5.3.5 Ranking .11
5.3.6 Rating and scoring .12
5.4 Descriptive tests.12
5.4.1 General.12
5.4.2 Qualitative sensory profile .13
5.4.3 Quantitative descriptive profile .13
5.4.4 Consensus profile .15
5.4.5 Free-choice profile.15
5.4.6 Flash profile .16
5.4.7 Deviation from reference profile.16
5.4.8 Temporal dominance of sensations (TDS).17
6 Analysis of results.17
6.1 General .17
6.2 Discrimination tests .17
6.2.1 General.17
6.2.2 Paired comparison test (see ISO 5495) .18
6.2.3 Triangle test (see ISO 4120) .19
6.2.4 Duo-trio test (see ISO 10399) .19
6.2.5 Two-out-of-five test .19
6.2.6 “A — not A” test (see ISO 8588) .19
6.2.7 Tetrad test .19
6.2.8 Treatment of “no difference” responses in discrimination tests .19
6.2.9 Systematic effects .20
6.2.10 Sequential approach (see ISO 16820) .20
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6.3 Tests using scales and categories .20
6.3.1 General.20
6.3.2 Classification .20
6.3.3 Grading (see ISO 4121) .20
6.3.4 Ranking (see ISO 8587) .20
6.3.5 Rating .21
6.3.6 Scoring .21
6.4 Analytical or descriptive tests .21
7 Test report .21
Annex A (informative) Statistical terms .23
Bibliography .25
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oSIST ISO 6658:2018
ISO 6658:2017(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: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 34, Food Products, Subcommittee SC 12,
Sensory analysis.
This third edition cancels and replaces the second edition (ISO 6658:2005), which has been technically
revised. The following changes have been made:
— the definition of “sensory analysis” was updated;
— a tetrad test was added to the discrimination tests as 5.2.7;
— the descriptive test in 5.4 was expanded by new methods;
— Clause 6 was updated;
— Table A.1 was deleted from Annex A;
— the Bibliography was updated and expanded.
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oSIST ISO 6658:2018
ISO 6658:2017(E)
Introduction
This document constitutes a general introduction to the methodology of sensory analysis and should be
read before undertaking the more detailed test procedures described in other International Standards.
It covers the general area of methodology and is intended to fulfil the following functions:
— to provide a brief background of the essential features of methods of sensory analysis for the user
of specific tests;
— to provide details of general requirements, procedures and interpretation of results common to all
or most tests;
— to provide sufficient guidance on requirements, procedures and interpretation of results for
the different specific tests to allow choice of the most appropriate procedure(s) for solution of a
particular problem.
It comprises three main aspects, covered in Clauses 4, 5 and 6.
It is essential that Clause 4 “General requirements” be read first. Clause 5 “Methods of test” describes,
in a general manner, all the main tests. Clause 6 is concerned with some general principles of data
collection and analysis of sensory data and also briefly covers general principles of statistical treatment
of the results.
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oSIST ISO 6658:2018
INTERNATIONAL STANDARD ISO 6658:2017(E)
Sensory analysis — Methodology — General guidance
WARNING — This document does not purport to address all of the safety problems, if any,
associated with its use. It is the responsibility of the user to establish appropriate safety and
health practices and to ensure compliance with any national regulatory conditions.
1 Scope
This document gives general guidance on the use of sensory analysis. It describes tests for the
examination of foods and other products by sensory analysis, and includes some general information
on the techniques to be used if statistical analysis of the results is required.
Generally these tests are intended only for objective sensory analysis. However, if a test can be used for
determining preference in hedonic test, this is indicated.
A hedonic test aims to determine the acceptability of the products and/or to determine preferences
among two or more products by the specified consumer population. The methods are effective for
determining whether a perceptible preference exists (difference in degree of liking), or whether no
perceptible preference exists (paired similarity test). General guidance for hedonic tests is given in
ISO 11136.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 5492, Sensory analysis — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5492 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
sensory analysis
science involved with the assessment of the organoleptic attributes of a product by the senses
4 General requirements
4.1 Basic information
This clause covers the general requirements common to all situations encountered in sensory analysis.
The information basic to these requirements is as follows.
a) The human response to one stimulus cannot be isolated from previous experiences or from other
sensory stimuli received from the environment. Nevertheless, influences arising from these two
sources can be controlled and the effect standardized.
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b) Variability in sensory response is inherent in any group of people used for testing and is
unavoidable; this can arise from inconsistencies within an individual, and through physiological
and psychological differences between individuals. However, with training, such a group can show
highly consistent individual responses. Recognition of these factors is important in the analysis of
results.
c) Systematic biases in sensory experiments involving human response can result in misleading
data and incorrect interpretation that can be difficult to identify. The factors that can result in
bias should be identified and controlled as far as possible by appropriate experimental design and
conduct of the tests.
d) The validity of the conclusions drawn from the results is dependent upon the test used and the way
it is conducted, including the questions that have been asked.
4.2 Statement of objectives
There are three main types of objective, as follows:
a) those in which the aim of the test is to categorize, rank or describe the product(s);
b) those in which the aim is to distinguish between two or more products; here it is important to
distinguish between the need to know
i) if there is a difference at all,
ii) how great is the magnitude of the difference,
iii) the direction (or quality) of that difference,
iv) the influence of that difference, e.g. with regard to preference, or
v) if all or only part of a population is detecting a difference;
c) those in which reassurance is sought that products are sufficiently similar to be used
interchangeably.
In sensory analysis, a given problem frequently requires appreciable discussion or thought before an
appropriate test is selected. This is because the initial concept of the problem may require clarification.
4.3 Choice of test
The choice of appropriate test depends largely on the nature of the test objective, but also needs to take
account of factors associated with the product, the assessors, the test environment, and the desired
level of analytical precision and statistical confidence in the conclusions. The action that would occur
based on the outcome of the test should be determined in advance.
For each test, an attempt is made in Clause 5 to give guidance as to its relevance. Preliminary tests may
be necessary to confirm the applicability of a given test.
Because of sensory fatigue and the effects of adaptation, only a limited number of samples can be
assessed during a session, depending on the nature of the test and the type of product. Some of these
effects can be moderated by appropriate rinse procedures and recovery between samples.
While the use of control samples is essential in most cases, their use naturally limits the number of
samples that can be assessed during any given session.
The statistical plan should always be determined before starting the tests. This is especially
recommended if the number of samples to be evaluated requires more than one session. Details of
statistical plans should be selected from specialized texts. Whatever test method is used, the sequential
testing approach described in ISO 16820 should be considered whenever it is desirable to keep the
number of samples or the number of assessors to a minimum.
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4.4 Choosing and training assessors
A sensory analysis panel constitutes a true “measuring instrument”, and consequently the results of
the analyses conducted depend on its members. The recruitment of persons willing to participate in a
panel, therefore, needs to be carried out with care and should be considered as a real investment, both
in time and financially. Management support in the organization is necessary if it is to be effective.
Sensory assessment may be made by three types of assessor: “sensory assessors”, “selected assessors”
or “expert sensory assessors”. Assessors can be “naive assessors” who do not have to meet any precise
criterion of selection or training, or people who have already taken part in some sensory tests (“initiated
assessors”). “Selected assessors” are assessors who have been selected and trained for the particular
sensory test. “Expert sensory assessors” are selected assessors who have been selected and trained
for a variety of sensory analysis methods and who are able to make consistent and repeatable sensory
assessments of products in one or several categories.
The selection and training methods to be employed depend on the tasks and methods that it is intended
to give to the “selected assessors”. Procedures for training assessors for descriptive tests are different
from those for training assessors in discrimination tests.
Detailed procedures and methods for selection and training of assessors are given in ISO 8586. It
should be noted that these methods sometimes only constitute a way of choosing the better candidates
amongst those who are available, rather than to satisfy predetermined criteria. Also, the selection
of assessors for their ability to discriminate and describe foods and other products is quite different
from that used for preference tests. The former tasks require selection and training, whereas the latter
requires only that the panel be representative of a specified sector of the population, for example, a
group of consumers.
If a selection procedure is to be carried out, some important criteria for choosing assessors are as
follows:
a) general ability to perform the specific sensory task;
b) availability with respect to normal employment;
c) motivation (willingness and interest);
d) good health (including the absence of specific allergies or treatment with medications) and good
dental and general hygienic condition.
The performance of “selected assessors” and “expert sensory assessors” should be monitored regularly
to ensure that the criteria by which they were initially selected continue to be met (see ISO 11132).
4.5 Material to be tested
The nature of the product to be tested determines the experimental protocol of the test, and may
also have an influence on the type of test that is required to satisfy the test objectives. For example,
a protocol in which foods are to be consumed hot will need to take into account the cooling rate of
the product and the likely effect on sensory attributes, and the changes in sensory attributes that may
occur in keeping the product hot prior to testing.
Methods of preparation and presentation of samples should be appropriate for the product and to the
problem concerned.
EXAMPLE 1 A product that is normally consumed hot is prepared in the usual manner and tested hot; however,
elevated temperatures can be used in some circumstances to increase the ease with which some flavours can be
evaluated.
EXAMPLE 2 A product that is normally consumed in discrete pieces is not homogenized in order to retain
textural characteristics. Care is needed, however, to ensure maximum uniformity between sub-samples for each
assessor; this includes similar portion size and uniformity of composition.
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General principles for product sampling (in accordance with International Standards relating to
the product under test) should be applied for test samples. In all cases, documentation of sample
identification codes or lot numbers is necessary. Valid conclusions can be drawn for a product as a
whole only if the samples tested are representative.
Carriers may sometimes be used for tests relating to the evaluation of products for which direct tasting
is not feasible (see ISO 5497), for example food ingredients.
Lighting conditions should be specified when appearance is being assessed. When the test concerns
only differences in flavour, the effect of colour differences may be partially masked by the use of lighting
conditions that minimize the colour difference.
Containers should be chosen so as not to affect the test or the product. These may include washable
ceramic or glass containers, or disposable plastic or paper containers, but shall not transfer chemical
materials that could result in taint. In particular, washable containers should be washed only in odour-
and taint-free detergents and rinsed in water, and polymeric and paper containers, including insulated
containers used for hot or cold samples, should be odour- and taint-free.
Palate cleansers may be used by the assessors between samples and between sessions, but care should
be taken to ensure that they do not influence the flavour of products to be assessed. Still and carbonated
water and bland foods (for example, unsalted crackers) may be used between samples and between
sessions. Checks on the water supply are desirable to ensure that it is bland and safe to consume. For
particular purposes, deionized water, glass-distilled water, low mineral content spring water, carbon-
filtered water or boiled tap water may be used, but it shall be noted that they are likely to have different
flavours.
4.6 Test room
Sensory analysis shall be conducted in a dedicated test room (see ISO 8589 for guidance). The aim shall
be to create for each assessor a separate environment with minimum distraction, so that each assessor
can quickly adjust to the nature of the new task(s). Extraneous activities, including preparation of the
samples, should not be allowed duri
...
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