INTERNATIONAL IS0

STANDARD
IS0 8586=1:1993(E)

Contents
Page

1 Scope . .. .. . .. .. . . ... .. . . ... . .. .. .. . . .. .. . .. .. . . .. . .. . ... . . ... .. . ... .. . ....*.......................* 1

2 Normative references ... . . .. .. . . .. .. . . .. .. . .. .. .. . .. ... . ... . .. .. .. . .. . .. .. . .. .. . .. .. .. .. .. 1

3 Definitions .. .. .. .. .. . .. .. .. .. .. . .. .. . . .. .. . . .. .. .. . .. .. . .. .. .. .. .. .. . .. .. .. . .. .. . . ... .. . .. .. . ... . I

4 Recruitment, preliminary screening and initiation .. .. . .. .. .. . .. .. . ... . 1

4.1 Principle . .. .. . .... . .. ... . . .. .. . .. .. .. . . .. .. . .. .. . .. ... . .. ... . .. .. .. . ...~.................. 1

4.2 Recruitment . ... . .. ... . .. . .. ...*........................................................ 1

4.3 Background information ..,...................................................... 3

4.4 Screening . .. .. ... .. ... . .. .. . .. . .. .. . .. . ... .. .. .. . ... .. .. .. .. ... .. .. . . ... . . .. .. . .. .. .. . ... 4

5 Training .. . ... ... ... ... .. .. .. . .. .. . .. .. . . .. .. .. . .. .. . .. .. .. .. .. .. . .. .. .. . .. .. . .. .. .. . . .. .. . ... 7

5.1 Principle . ... . .. ... . ... .. . .. .. . .. . .. . . .. .. .. . .. .. . .. ... . ... . .. . ... .. . . .. .. . .. .. .. . . .. .. .. .. 7

5.2 General .. .. .. .. . ... . .. .. . .. . .. . .. .. . . .. .. .. . .. .. . .. ... . .. ... . . ... . .. . ..“.................. 7

5.3 Assessment procedure

iTeh STANDARD PREVIEW
. .. . . .. .. .. .. ..~................*......................... 7

5.4
(standards.iteh.ai)
Training in detection and recognition of tastes and odours . .. 7

5.5 Training in the use of scales ISO 8586-1:1993

,,,,....,.,.,..................................... 8
https://standards.iteh.ai/catalog/standards/sist/fca79079-46a4-446b-b5a2-
5.6 Training in the development and use of5ebe778eb7c4/iso-8586-1-1993
descriptors (profiles) 8

5.7 Practice . ... .. . .. ... . .. .. . .. .. . .. .. .. . .. .. .. . .. .. . .. ... . .. ... . .. .. . .. . .. .. . .. .. .. ... . .. .. .. 9

5.8 Specific product training . .. . . .. .. . ... .. . .. ... . .. ... . .. .. .. . . .. .. . .. .. .. . .. .. . .. .. 9

6 Final choice of panels for particular methods .. .. . . .. .. . .. .. .. . .. .. . .. .. 9

6.1 Principle .. .. . .. . ... . .. .. . .. .. .. . .. .. . .. .. .. . .. .. .. .. .. .. .. ... ... . .. . .. . .. . .. .. .. . .. . .. .. .. 9

6.2 Difference assessments . .. . .. .. .. .. .. .. . ... .. . ... .. . .. . .. . .. . ... .. .. .. . .. .. . .. .. 9

6.3 Ranking assessment .. . ... .. . .. .. .. .. .. .. .. .. .. .. .. .. . .. . .. . .. . .. . .. .. .. . .. . .. .. .. 9

6.4 Rating and scoring . ... .. .. .. .. . .. ... . .. .. .. . ... .. .. .. .. . .. . .. . . ...*................. 9

6.5 Qualitative descriptive analysis . ... . .. ... . .. .. .. . . .. . .. . . ... . . .. .. . .. .. .. . . IO

6.6 Quantitative descriptive analysis ..,,,,.....,.,,................~.......... 10

6.7 Assessors for particular assessments ..,....*.....,.................... 10

0 IS0 1993
All rights reserved. No part of this publication may be reproduced or utilized in any form or
by any means, electronic or mechanical, including photocopying and microfilm, without per-
mission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland

II
 IS0 8586=1:1993(E)

7 Monitoring of selected assessors .. . ... .. . ... .. ... .. . .. .. . . .. . .. . . .. . .. . .. . . IO

Annexes

A Use of analysis of variance in the choice of selected assessors for

scoring . .. .. .. .. .. .. . .. .. . .. .. .. . . ... . . .. .. .. .. ... . .. .. . .. . ... . ... .. . .. . .. . .. .. . . .. .. . .. . .. 11

B Example of practical application ... . .. .. .. ... . .. ... .. . .. . .. . . ... . . .. .. .. . .. . . 13

C Bibliography ,..,....,...........,............,..............,..,........................ 15

iTeh STANDARD PREVIEW

(standards.iteh.ai)
ISO 8586-1:1993
https://standards.iteh.ai/catalog/standards/sist/fca79079-46a4-446b-b5a2-
5ebe778eb7c4/iso-8586-1-1993
IS0 8586=1:1993(E)

Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical Commission
(I EC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote. iTeh STANDARD PREVIEW
International Standard IS0 (standards.iteh.ai)
8586-l was prepared by Technical Committee
lSO/TC 34, AgriculturaI food products, Sub-Committee SC 12, Sensory
analysis. ISO 8586-1:1993
https://standards.iteh.ai/catalog/standards/sist/fca79079-46a4-446b-b5a2-
IS0 8586 consists of the following parts, under the general title Sensory
analysis - General guidance for the selection,5ebe778eb7c4/iso-8586-1-1993
training and monitoring of
assessors:

- Part I: Selected assessors

- Part 2: Experts
Annex A forms an integral part of this part of IS0 8586. Annexes B and
C are for information only.

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 IS0 8586=1:1993(E)

Introduction
A sensory analysis panel constitutes a true “measuring instrument”, and
consequently the results of the analyses conducted will depend on its
members.

The recruitment of persons willing to participate in a panel therefore needs

to be carried out with care and to be considered as a real investment, both
in time and financially.

Sensory assessment may be made by three types of assessor:

- “assessors”,

- “selected assessors”, and

iTeh STANDARD PREVIEW
- “experts”.
(standards.iteh.ai)
Assessors can be “naive assessors” who do not have to meet any precise
criterion, ISO
or 8586-1:1993
“initiated assessors” who have already participated in sensory
tests.
https://standards.iteh.ai/catalog/standards/sist/fca79079-46a4-446b-b5a2-
5ebe778eb7c4/iso-8586-1-1993
“Selected assessors” are assessors who have been selected and trained.

” Experts ” can be “expert assessors” who have already demonstrated

particular acuity in panel work and have developed a good long-term
memory, or “specialized expert assessors” who draw on additional
knowledge gained in particular fields.

This part of IS0 8586 concerns only the recruitment, selection, training
and monitoring of candidates intended to become selected assessors. The
recruitment, selection, training and monitoring of candidates intended to
become experts will form the subject of IS0 8586-2.

The selection and training methods to be employed depend on the tasks

which one intends to give the selected assessors. It should be pointed out
that these methods sometimes only constitute a way of choosing the
better candidates among those who are available, rather than those who
satisfy predetermined criteria. This is particularly the case when it is
necessary to constitute internal panels.

A preliminary selection of candidates has to be undertaken at the recruit-

ment stage, in order to eliminate those who would be unsuited for sensory
analysis. However, the final selection can only be made after training and
the completion of the envisaged tasks.

The recommended procedure involves

a) recruitment and preliminary screening of na’ive assessors;

b) training of naive assessors who will become initiated assessors;

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IS0 8586=1:1993(E)

c) selection of initiated assessors according to ability to perform particular

tests; they will then become selected assessors;

selection following the performance of an actual sensory assessment

(useful in the case of descriptive analyses);

possible training of selected assessors to become expert assessors.

In certain cases (especially for descriptive sensory analysis), the panel may
be divided into specialized sub-groups.
The exact procedures covered by a) and b) and the nature of the tests
performed in c) and d) depend on the tasks which the panel is to perform.
The performance of selected assessors should be monitored regularly to
ensure that the criteria by which they were initially selected continue to
be met.
The entire process is illustrated in the following diagram.

Recruitment, preliminary Clause 4

screening and initiation

Training in general principles Clause 5

and methods t-
I
iTeh STANDARD PREVIEW
I

purposes
(standards.iteh.ai)
SeLection for particular Clause 6

ISO 8586-1:1993
https://standards.iteh.ai/catalog/standards/sist/fca79079-46a4-446b-b5a2-
Monitoring performance Clause 7
5ebe778eb7c4/iso-8586-1-1993
+

Possible training as expert

assessors

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INTERNATIONAL STANDARD IS0 8586=1:1993(E)

Sensory analysis - General guidance for the

selection, training and monitoring of assessors -

Part 1:
Selected assessors

1 Scope 4 Recruitment, preliminary screening

and initiation
This part of IS0 8586 specifies criteria for the selec-
iTeh STANDARDaRecruitment
PREVIEW
tion and procedures for the training and monitoring
of selected assessors. It supplements the information
is an important starting point in forming
panel of selected assessors. Different recruitment
given in IS0 6658.
(standards.iteh.ai)
methods and criteria are available and there are vari-
ous tests that can be used for screening candidates
for suitability for further training.
ISO 8586-1:1993
2 Normative references
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4.1 Principle
5ebe778eb7c4/iso-8586-1-1993
The following standards contain provisions which,
through reference in this text, constitute provisions To recruit candidates and to select those most suit-
of this part of IS0 8586. At the time of publication, the able for training as selected assessors.
editions indicated were valid. All standards are subject
to revision, and parties to agreements based on this 4.2 Recruitment
part of IS0 8586 are encouraged to investigate the
possibility of applying the most recent editions of the The following three questions arise when recruiting
standards indicated below. Members of IEC and IS0 persons to form a sensory analysis panel:
maintain registers of currently valid International
Standards. - where should one look for the people who will
constitute the group ?
IS0 4120:1983, Sensory analysis - Methodology -
Triangular test. - how many people shall be selected?

IS0 4121 :I 987, Sensory analysis - Methodology - - how shall the people be selected?
Evaluation of food products by methods using
scales. 4.2.1 Types of recruitment

IS0 54927 992, Sensory analysis - Vocabulary. Two types of recruitment are available to organiz-
ations:
IS0 6658: 1985, Sensory analysis - Methodology -
General guidance. - recruit through the personnel department of the
organization (internal recruitment), or

- recruit people from outside the organization (ex-

3 Definitions ternal recruitment).
For the purposes of this part of IS0 8586, the defi- It is possible to constitute a mixed panel made up of
nitions given in IS0 5492 apply. both types of recruitment.

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IS0 8586=1:1993(E)

4.2.1 .I Internal recruitment - a better confidentiality vis-&is the results is en-

sured, which is particularly important if it is a
The candidates are recruited from amongst the office, question of research work; and
plant or laboratory staff. It is advisable to avoid those
persons who are too personally involved with the - there is better stability of the panel with time.
products being examined, in particular those involved
at the technical or commercial level, because they
4.2.2.1.2 Disadvantages
may cause the results to be biased.
In this type of recruitment, it is vital that the organiz- The disadvantages are that
ation’s general management and hierarchy provide
their support and make it known that sensory analysis - candidates are influenced in their judgements (by
is considered as forming part of everyone’s work. This knowledge of the products);
can be made known at the hiring stage of the per-
sonnel. - it is difficult to allow for the evolution of the
organization’s products (people are influenced by
their familarization with the organization’s prod-
4.2.1.2 External recruitment
ucts);
The recruitmen t is conducted outside the organiz-
- replacement of candidates is more difficult (limited
ation
number of persons in small organizations);
The most commonly used means for this purpose are:
- lack of availability.
- recruitment through classified advertisement in
the local press, in specialized publications, or in 4.2.2.2 External recruitment
newspapers which are distributed free of charge,
etc. (in this case, all types of people will reply and
iTeh STANDARD
it will be necessary to carry out a selection); 4.2.2.2.1PREVIEW
Advantages

- opinion poll institutes; certain of these (standards.iteh.ai)

institutes The advantages are that
can provide the names and addresses of persons
likely to be interested; there is a wide range of choice;
ISO 8586-1:1993
- in-house “consumer”
https://standards.iteh.ai/catalog/standards/sist/fca79079-46a4-446b-b5a2-
files, compiled as a result there is subsequent supply of new persons by
of advertizing campaigns or complaints; 5ebe778eb7c4/iso-8586-1-1993
word of mouth;

- persons visiting the organization; there are no problems with hierarchy;

- personal acquaintances. selection is much easier, without the risk of of-

fending people if they are unsuitable;
4.2.1.3 Mixed panel easy availability.
A mixed panel ma Y be forme d using inte rnal and ex-
ternal recruitment, In va ria ble Pr8oportions. 4.2.2.2.2 Disadvantages

The disadvantages are that

4.2.2 Advan tages and disadva ntages of internal
and external recruitme nt
- the method is expensive (remuneration, paper-
work);
Organizations may wish to use independent internal
or external panels for different tasks.
this method is better suited to urban communities
where there is a sufficient number of inhabitants;
4.2.2.1 Internal recruitment however, in rural areas, advantage can be taken
of co-operatives (e.g. milk, wine);
4.2.2.1 .I Advantages
since it is necessary that the individuals are avail-
The advantages are that able, one sometimes encounters an inordinate
number of (old age) pensioners or unemployed
- the people are on the spot; women or even students; it is more difficult to re-
cruit working people; and
- it is not necessary to make provision for any pay-
ment (however, in order to maintain interest, it after having paid for the selection and training, one
may be desirable to offer small presents or perks); risks people leave at a moment’s notice.

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 IS0 8586=1:1993(E)

4.2.3 Number of persons to be selected physical and intellectual abilities, in particular the ca-
pacity to concentrate and to remain unaffected by
Experience has shown that, after the recruitment, the external influences. If the candidate is then required
selection procedures eliminate approximately half the to evaluate only one type of product, knowledge of
people for reasons such as gustative sensitivity, ma- all aspects of that product may be beneficial. It is then
terial conditions, etc. possible to choose expert assessors from amongst
those candidates who have shown an aptitude for
The number of persons to be recruited will vary de- sensory analysis of this product.
pending on the following elements:

- the financial means and the requirements of the 4.3.4 Health

organization;
The candidates shall be in good general health. They
- the types and frequency of tests to be conducted; shall not suffer from any disabilities which may affect
their senses, or from any allergies or illnesses, and
- whether or not it is necessary to interpret the re- shall not take medication which might impair their
sults statistically. sensory capacities and thus affect the reliability of
their judgements. It may be useful to know whether
It is not desirable for a panel to operate with less than the candidates have dental protheses, since they can
10 selected assessors. It is necessary to recruit at have an influence in certain types of evaluation in-
least two to three times the number of persons actu- volving texture or flavour.
ally required to constitute the final panel. For example,
in order to obtain a panel of 10 persons, it is necess- Colds or temporary conditions (for instance, preg-
ary to recruit 40 and to select 20. nancy) should not be a reason for eliminating a candi-
date.
For specialized purposes, a higher level of recruitment
will be required.
iTeh STANDARD4.3.5PREVIEW
Ability to communicate

4.3 Background information

(standards.iteh.ai)
The ability of candidates to communicate
scribe the sensations they are perceiving
and de-
when as-
Background information on the candidates may be sessing is particularly important when considering
obtained by submitting them to a combination ISO 8586-1:1993
of candidates for descriptive analyses. This ability can be
clearly understood questionnaires coupled with inter-
https://standards.iteh.ai/catalog/standards/sist/fca79079-46a4-446b-b5a2-
determined at the interview and again during screen-
views by persons experienced in sensory analysis.
5ebe778eb7c4/iso-8586-1-1993
ing tests (see 4.4.6).
The aspects specified in 4.3.1 to 4.3.8 shall be ex-
plored.
4.3.6 Availability
4.3.1 Interest and motivation
Candidates shall be available to attend both training
and subsequent assessments. Personnel who travel
Candidates who are interested in sensory analysis and
frequently or have continual heavy work-loads are of-
the product or products to be investigated are likely ten unsuited for sensory work.
to be more motivated and hence are likely to become
better assessors than those without such interest and
motivation. 4.3.7 Personality characteristics

4.3.2 Attitudes to foods Candidates shall show interest and motivation for the
tasks and shall be willing to persevere with tasks de-
Strong dislikes for certain foods and beverages, in manding prolonged concentration. They shall be
particular those which it is proposed to assess, to- punctual in attending sessions and shall be reliable
gether with any cultural, ethnic or other reasons for and honest in their approach.
not consuming certain foods or beverages, should be
determined. Candidates who are venturesome in their 4.3.8 Other factorsl)
eating habits often make good assessors for descrip-
tive analyses.
Other information which may be recorded during
recruitment are name, age group, sex, nationality,
4.3.3 Knowledge and aptitude educational background, current occupation and ex-
perience in sensory analysis. Information on smoking
The initial sensory perceptions of the candidates have habits may also be recorded, but candidates who
to be interpreted and expressed, requiring certain smoke shall not be excluded on these grounds.

It is necessary that any files on individual persons comply with the legal requirements of the country concerned.
IS0 8586=1:1993(E)

4.4 Screening
Table 1 - Examples of materials and
Various tests which may be used for screening pur- concentrations for matching tests
poses are described below.
Concen-
Concen-
The choice of the tests and of the materials to be tration
tration
used is conducted on the basis of the envisaged ap- in
in water
Taste or ethanolI)
plications and of the properties to be assessed. Material at room
at room
odour temper-
temper-
ature
4.4.1 Types of screening tests ature
g/l 4/l
All the tests described have the dual function of fam-
iliarizing the candidates with both the methods and Taste
the materials used in sensory analysis. They are div-
ided into three types as follows: Sweet Sucrose 16
Acid Tartaric acid or 1
a) those aimed at determining impairment; citric acid
Bitter Caffeine 015
b) those aimed at determining sensory acuity; Salty Sodium chloride 5
c) those aimed at evaluating a candidate’s potential Astringent Tan n ic acid*) 1
or quercitin 0,5
for describing and communicating sensory per-
or potassium alu- Of5
ceptions. minium sulfate
(alum)
Tests, the results of which will be used to aid selec-
tion, should only be carried out after previous experi- Metallic Ferrous sulfate, 0,Ol
ence followed by familiarization. hydrated,
iTeh STANDARD PREVIEW
The tests shall be conducted in the actual environ-
FeS0,.7H,O 3)

propriate environment in accordance

(standards.iteh.ai)
ment in which products are evaluated and in an ap-
with the
Odour
Lemon, Citral (C,,H,,O) - 1 x 1o-3
recommendations given in IS0 8589. They shall be fresh
followed by interviews. Several tests described in this ISO 8586-1:1993
Vanilla Vanillin (C,H,O,)
https://standards.iteh.ai/catalog/standards/sist/fca79079-46a4-446b-b5a2- - 1 x 1o-3
part of IS0 8586 are based on those described in
IS0 6658. 5ebe778eb7c4/iso-8586-1-1993
Thyme Thymol (C,0H,40) - 5 x 1o-4
Floral, lily Benzyl acetate 1 x 1o-3
The selection of assessors should take into account of the GH, 202)
the intended application, the performance of the can- valley,
didates at the interviews and their potential rather jasmine
than their current performance. Candidates with high
success rates are to be expected to be more useful I) Stock solutions are prepared with ethanol, but the
than others, but those showing improving results with final dilution is made with water and shall not contain
repetition are likely to respond well to training. more than 2 % of alcohol.
2) This material is not very soluble in water.
4.4.2 Colour vision 3) To avoid the appearance of a yellow coloration due
to oxidation, it is necessary to use a solution freshly
Candidates with abnormal colour vision are unsuitable prepared from neutral or slightly acid water. However,
for tasks involving judgement or matching of colours. if a yellow coloration occurs, present the solutions in
Assessment of colour vision can be carried out by a closed opaque containers or under dim or coloured light.
qualified optician or, in the absence of such a person
and associated equipment, by using an effective test,
for example the Ishihara*) test.

4.4.4 Matching test

4.4.3 Ageusia and anosmia

It is desirable that candidates be tested to determine Samples of sapid and/or olfactory materials (see
their sensitivity to substances which may be present table I) at well above threshold levels are prepared.
in small concentrations in products, in order to detect Each sample is attributed a different, random, three-
ageusia, anosmia or possible lack of sensitivity (see digit code number. Candidates are presented with
IS0 3972). one sample of each type and are allowed to familiarize
themselves with them (see IS0 6658).

2) See ISHIHARA, S. Tests for colourblindness. Kanahara Shuppan Co. Ltd., Tokyo-Kyoto, Japan, 1971.

4
 IS0 8586=1:1993(E)

They are then presented with a series of the same 4.4.5.2 Tests for discrimination between levels
materials labelled with different random numbers. of intensity of a stimulus
They are asked to match each of them to one of the
original set and to describe the sensation they are These tests are based on the ranking test described
experiencing. in IS0 8587. The tests are carried out using stimuli for
taste, odour (only for very small concentrations), tex-
Approximately twice as many new samples as original ture (mouth and hand), and colour.
samples shall be presented. None of the samples
shall be so intense as to produce strong carry-over For each test, four samples having different inten-
effects and hence to influence subsequent tasting. sities of the property are presented in a random order
Odourless flavourless water shall be made available to the candidates, who are required to put them in
for cleansing the palate between samples. order of increasing intensity. This random order shall
be the same for all candidates, to ensure that com-
Examples of materials that may be used are given in
parisons of their performance are not influenced by
table 1. For these substances and concentrations, it is
the effects of different orders of presentation.
generally accepted that candidates who make fewer
than 80 % correct matches should not be chosen as A satisfactory level of success in this task can be
selected assessors. A correct description of the sen- specified only in relation to the particular intensities
sations produced by the samples is desirable but less
used.
important.
Examples of products that may be used are given in
4.4.5 Acuity and discriminating ability table3; for these concentrations, candidates who in-
vert the order of more than one adjacent pair of sam-
The two following tests are recommended. ples shall be considered unsuitable as selected
assessors for this type of analysis.
4.4.5.1 Tests for detection of a stimulus

These tests are based

iTeh STANDARD Table
on the triangular test; see
PREVIEW
3 - Examples of products which may be
used in discrimination tests
IS0 4120. (standards.iteh.ai) Concentration
One material at a time is tested. Two samples of the in water at
Test ProductI)
test material and one sample of water or other ISO 8586-1:1993
neutral room
medium, or one sample https://standards.iteh.ai/catalog/standards/sist/fca79079-46a4-446b-b5a2-
of the test material and two temperature
of water or other neutral medium, are 5ebe778eb7c4/iso-8586-1-1993
presented to
each candidate. The concentration of the test material Taste discrimi- Citric acid a1 g/l; 03 5 g/l;
shall be at the supra-threshold level. nation 0,22 g/l; 0,34 g/l;
Odour discrimi- lsoamyl acetate 5 ppm; 10 ppm;
The test materials, their concentrations and the neu- nation 20 ppm; 40 ppm;
tral medium (if used) shall be chosen by the organizer
Texture discrimi- To suit the in- -
in relation to the types of assessment for which the
nation dustry con-
candidates wil! be used. Preferably candidates should cerned (e.g.
have 100 % correct responses. cream cheese,
puree, gelatine)
An inability to detect differences after several rep-
etitions indicates unsuitability for this type of test. Colour discrimi- Cloth, colour Intensity of a
nation scales, etc. colour ranging,
Examples of materials which may be used in de- for example,
from dark red to
tection tests are given in table 2.
light red

Table 2 - Examples of materials which may be 1) Other appropriate products showing a graduation in
used in detection tests characteristics may also be used.
Concentration in
Material water at room
temperature

Caffeine 027 g/l 4.4.6 Descriptive ability

Citric acid 0,60 g/l
Sodium chloride
These tests are aimed at determining a candidate’s
2 g/l
ability to describe sensory perceptions. Two tests are
Sucrose 12 g/l advocated, one covering odour stimuli and the other
cis-3-Hexen-l-01 0,4 ml/l textural stimuli. The tests are conducted as combined
assessments and interviews.