SIST ISO 22935-1:2024
(Main)Milk and milk products — Sensory analysis — Part 1: Recruitment, selection, training and monitoring of assessors (ISO 22935-1:2023)
Milk and milk products — Sensory analysis — Part 1: Recruitment, selection, training and monitoring of assessors (ISO 22935-1:2023)
This document gives general guidance for the recruitment, selection, training, and monitoring of assessors for sensory analysis of milk and milk products.
It specifies criteria for the selection, and procedures for the training and monitoring, of selected assessors and expert sensory assessors for milk and milk products. It supplements the information given in ISO 8586 that deals with expert assessors.
Lait et produits laitiers — Analyse sensorielle — Partie 1: Recrutement, sélection, entraînement et contrôle des sujets (ISO 22935-1:2023)
Le présent document spécifie des recommandations pour le recrutement, la sélection, l’entraînement et le contrôle des sujets pour l’analyse sensorielle du lait et des produits laitiers.
Il spécifie les critères de sélection et des modes opératoires pour l’entraînement et le contrôle des sujets qualifiés et des sujets experts sensoriels dans l’analyse sensorielle du lait et des produits laitiers. Il constitue également un complément aux informations données dans l’ISO 8586 traitant des sujets experts sensoriels.
Mleko in mlečni izdelki - Senzorična analiza - 1. del: Nabor, izbira, usposabljanje in spremljanje ocenjevalcev (ISO 22935-1:2023)
Standard ISO 22935-1 | IDF 99-1 podaja splošna navodila za novačenje, izbiro, usposabljanje in spremljanje ocenjevalcev za senzorično analizo mleka in mlečnih proizvodov.
Določa merila za izbiranje, usposabljanje ter spremljanje izbranih ocenjevalcev in strokovnih senzoričnih ocenjevalcev za mleko in mlečne proizvode. Standard dopolnjuje informacije v standardu ISO 8586-1 in v delih standarda ISO 8586-2 v zvezi s strokovnimi senzoričnimi ocenjevalci.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2024
Mleko in mlečni izdelki - Senzorična analiza - 1. del: Nabor, izbira, usposabljanje in
spremljanje ocenjevalcev (ISO 22935-1:2023)
Milk and milk products — Sensory analysis — Part 1: Recruitment, selection, training
and monitoring of assessors (ISO 22935-1:2023)
Lait et produits laitiers — Analyse sensorielle — Partie 1: Recrutement, sélection,
entraînement et contrôle des sujets (ISO 22935-1:2023)
Ta slovenski standard je istoveten z: ISO 22935-1:2023
ICS:
03.100.30 Vodenje ljudi Management of human
resources
67.100.01 Mleko in mlečni proizvodi na Milk and milk products in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
INTERNATIONAL ISO
STANDARD 22935-1
IDF 99-1
Second edition
2023-04
Milk and milk products — Sensory
analysis —
Part 1:
Recruitment, selection, training and
monitoring of assessors
Lait et produits laitiers — Analyse sensorielle —
Partie 1: Recrutement, sélection, entraînement et contrôle des sujets
Reference numbers
IDF 99-1:2023(E)
IDF 99-1:2023(E)
© ISO and IDF 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office International Dairy Federation
CP 401 • Ch. de Blandonnet 8 Silver Building • Bd Auguste Reyers 70/B
CH-1214 Vernier, Geneva B-1030 Brussels
Phone: +41 22 749 01 11 Phone: +32 2 325 67 40
Fax: +32 2 325 67 41
Email: copyright@iso.org Email: info@fil-idf.org
Website: www.iso.org Website: www.fil-idf.org
Published in Switzerland
ii
IDF 99-1:2023(E)
Contents Page
Forewords .iv
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Recruitment . 2
5 Screening. 2
5.1 Screening form and requirements . 2
5.2 Preparation of test samples for screening . 3
5.3 Screening tests, materials and methods . 4
5.3.1 General . 4
5.3.2 Odour recognition . 4
5.3.3 Basic taste recognition . 4
5.3.4 Ranking tests . 5
5.3.5 Difference testing . 6
5.3.6 Descriptive ability and group discussion . 9
5.3.7 Marking schedule summary . . 10
6 Selection .11
7 Requirements for assessors in the panel .12
8 Training and monitoring of assessors for dairy products .12
8.1 General .12
8.2 References. 13
9 Performance .16
Bibliography .17
iii
IDF 99-1:2023(E)
Forewords
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 of 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
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5,
Milk and milk products, and the International Dairy Federation (IDF). It is being published jointly by ISO
and IDF.
This second edition cancels and replaces the first edition (ISO 22935-1 | IDF 99-1:2009), which has been
technically revised.
The main changes are as follows:
— the Normative references have been updated;
— a few changes have been made to reference materials.
A list of all parts in the ISO 22935 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
IDF 99-1:2023(E)
IDF (the International Dairy Federation) is a non-profit private sector organization representing the
interests of various stakeholders in dairying at the global level. IDF members are organized in National
Committees, which are national associations composed of representatives of dairy-related national
interest groups including dairy farmers, dairy processing industry, dairy suppliers, academics and
governments/food control authorities.
ISO and IDF collaborate closely on all matters of standardization relating to methods of analysis
and sampling for milk and milk products. Since 2001, ISO and IDF jointly publish their International
Standards using the logos and reference numbers of both organizations.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. IDF 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.
This document was prepared by the IDF Standing Committee on Statistics and Automation and ISO
Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is being
published jointly by ISO and IDF.
The work was carried out by the IDF/ISO Action Team S17 of the Standing Committee on Statistics and
Automation under the aegis of its project leader Dr H. Kraggerud (NO).
v
IDF 99-1:2023(E)
Introduction
The purpose of the ISO 22935 | IDF 99 series is to give guidance on methodology for sensory analysis
and the use of a common nomenclature of terms for milk and milk products.
To achieve that, the ISO 22935 | IDF 99 series is divided into three parts.
ISO 6658 should be consulted for an overview of sensory methods other than the one provided in
ISO 22935-3 | IDF 99-3.
The principles described are largely derived from various International Standards on the topic.
It is important that safety issues are handled during sensory evaluations (see ISO 20613).
vi
INTERNATIONAL STANDARD
IDF 99-1:2023(E)
Milk and milk products — Sensory analysis —
Part 1:
Recruitment, selection, training and monitoring of
assessors
1 Scope
This document gives general guidance for the recruitment, selection, training, and monitoring of
assessors for sensory analysis of milk and milk products.
It specifies criteria for the selection, and procedures for the training and monitoring, of selected
assessors and expert sensory assessors for milk and milk products. It supplements the information
given in ISO 8586 that deals with expert assessors.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4120, Sensory analysis — Methodology — Triangle test
ISO 4121, Sensory analysis — Guidelines for the use of quantitative response scales
ISO 5492, Sensory analysis — Vocabulary
ISO 5496, Sensory analysis — Methodology — Initiation and training of assessors in the detection and
recognition of odours
ISO 6658, Sensory analysis — Methodology — General guidance
ISO 8586:2012, Sensory analysis — General guidelines for the selection, training and monitoring of selected
assessors and expert sensory assessors
ISO 8587, Sensory analysis — Methodology — Ranking
ISO 8589, Sensory analysis — General guidance for the design of test rooms
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4121, ISO 5492, ISO 5496,
ISO 6658, ISO 8586 and ISO 8589 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
IDF 99-1:2023(E)
3.1
sensory analysis
science involved with the assessment of the sensory attributes of a product by the senses
[SOURCE: ISO 5492:2008, 1.1, modified — “sensory” replaced “organoleptic” in the definition.]
3.2
expert sensory assessor
selected assessor with a demonstrated sensory sensitivity and with considerable training and
experience in sensory testing, who is able to make consistent and repeatable sensory assessments of
various products
Note 1 to entry: Examples of “various products” are “dairy products”.
[SOURCE: ISO 5492:2008, 1.8, modified — Note 1 to entry added.]
3.3
appearance
all the visible attributes of a substance or object
Note 1 to entry: For a dairy product, the visual attributes are both internal and external, and include shape,
colour, loose liquid, phase separation, wanted or unwanted particles, and openings.
[SOURCE: ISO 5492:2008, 3.1, modified — Note 1 to entry added.]
3.4
fingerfeel
mixed experience derived from sensations on the fingers that relate to physical properties of a stimulus
3.5
flavour
complex combination of the olfactory, gustatory and trigeminal sensations perceived during tasting
[SOURCE: ISO 5492:2008, 3.20, modified — Note 1 to entry deleted.]
4 Recruitment
Assessors can be recruited from within a company (laboratory staff, production staff, administration
staff, etc.), who are not involved with project work, or from outside a company. Outside assessors can be
recruited by advertisement or by word of mouth. The panel candidates should have an understanding
of the amount of time that will be required for the screening process and for actual panel work. A large
enough pool of available candidates should be screened in order to have enough assessors available to
select from when forming a panel. The trainee assessor should have satisfactory personal qualifications
for assessments and should be pre-selected by:
a) the use of screening tests to assess the ability of candidates to perceive, discriminate and describe
sensory attributes;
b) a general understanding of the concepts of sensory evaluation;
c) a general liking or interest in dairy products.
5 Screening
5.1 Screening form and requirements
Potential applicants should go through two forms of screening via an interview and sensory screening
tests. During the interview, the applicants should fill out a pre-screening form which indicates the times
that they are available for panels and any health issues they can have, e.g. arthritis which can interfere
IDF 99-1:2023(E)
with the evaluation of product texture in-hand (fingerfeel), lactose intolerance, food allergies, wearing
of dentures, smoking status, and any other issues of concern.
Flavoured water solutions and dairy products should be used to indicate if the potential assessor can
recognize specific tastes or flavours at different intensities. The potential evaluator shall be able to
detect certain flavours within complex dairy products. The following three sessions each take assessors
approximately 45 min to 1 h to complete. These screening exercises are suggestions only and may be
adapted to the application area of the assessors. The sessions described in Tables 1 to 3 may be broken
down into smaller or larger sessions depending on how much time is available.
Table 1 — Session 1 — Basic odour and taste recognition
Test Reference Result
1 5.3.2 Odour recognition
2 5.3.3 Basic taste recognition
3 5.3.4, Table 8 Ranking of basic taste — sweet
4 5.3.4, Table 9 Ranking of basic taste — sour
5 5.3.4, Table 10 Ranking of basic taste — salty
6 5.3.4, Table 11 Ranking of basic taste — bitter
Table 2 — Session 2 — Milk powder and cream products
Test Reference Result
7 5.3.5, Table 14 Triangle test — milk powder
8 5.3.5, Table 15 Triangle test — butter
9 5.3.5, Table 16 Triangle test — salted butter
10 5.3.6.3 Round table discussion — cream evaluation
11 5.3.4, Table 12 Ranking of texture — body/creaminess
12 5.3.5, Table 13 Triangle test — aged milk powder
Table 3 — Session 3 — Cheese
Test Reference Result
13 5.3.5, Table 16 Triangle test — cheese
14 5.3.6.2 Round table discussion — cheese evaluation
15 5.3.5, Table 16 Triangle test — bitter cheese
16 5.3.5, Table 17 Triangle test — cheese firmness
17 5.3.5, Table 17 Triangle test — cheese smoothness
Mark each section as per each marking schedule. Other examples of screening exercises can be found in
ISO 8586.
5.2 Preparation of test samples for screening
5.2.1 If possible, prepare test samples on the day of the evaluation.
5.2.2 For screening purposes, it is easier to serve test samples in the same order to all assessors.
5.2.3 If appropriate, use test sample questionnaires for all screening exercises found in ISO 4120
(triangle test), ISO 8587 (ranking test), ISO 6658 and ISO 4121 (scales).
IDF 99-1:2023(E)
5.3 Screening tests, materials and methods
5.3.1 General
The screening tests, materials and methods presented in this clause are recommendations only. They
can be adapted to suit the needs of an individual company.
5.3.2 Odour recognition
Follow the instructions outlined in ISO 8586:2012, 5.4.1, for details on how to prepare the test samples
and conduct this test. Table 4 suggests other aromas that can be used.
Table 4 — Examples of olfactory materials for odour description test
Blind code Sample preparation
(example)
981 Citronella oil (lemon, cleaning fluid)
194 Orange
229 Caramel
371 Butyric acid
926 Acetic acid
174 Ammonia
a
746 (Z)-hex-3-en-1-ol
831 Oct-1-en-3-ol
556 Vanilla
a
In older literature, known as cis-hex-3-en-1-ol.
Candidates are graded according to performance, as shown in Table 5. For each sample, a total of three
points can be achieved. If the assessor uses words other than those listed in Table 5, score appropriately.
Table 5 — Marking schedule for odour recognition
Correct answer
Sample
3 points 2 points 1 point
Citronella oil Citronella oil Lemony, cleaning fluid Citrus, fruity
Orange Orange Lemon Citrus, fruity
Caramel Caramel Vanilla, malt, toasted Sweet
Butyric acid Rancid butter Parmesan cheese Vomit, baby burp
Acetic acid Acetic acid Vinegar Sour/off milk
Ammonia Ammonia Cleaning fluid, urine Pungent
(Z)-hex-3-en-1-ol Green grass Green beans Green vegetable
Oct-1-en-3-ol Mushroom Cellar, musty Mouldy
Vanilla Vanilla Custard, dessert Sweets, candy
5.3.3 Basic taste recognition
The solutions can be prepared as shown in Table 6. Present the solutions to the assessors in the same
order, and one of the solutions twice. Ask the assessor to identify the basic taste that is represented by
the solution.
IDF 99-1:2023(E)
Table 6 — Basic taste solutions
Blind code Answer Concentration Sample preparation
(examples)
10 g/l sucrose
683 Sweet 10 g sucrose + 1 l water
(1 % mass fraction)
2 g/l NaCl
429 Salty 2 g NaCl + 1 l water
(0,2 % mass fraction)
0,3 g/l citric acid
662 Sour 0,3 g citric acid + 1 l water
(0,03 % mass fraction)
0,3 g/l caffeine
353 Bitter 0,3 g caffeine + 1 l water
(0,03 % mass fraction)
0,6 g monosodium glutamate or 0,18 g umami mixture
0,6 g/l monosodium
Umami (50 % mass fraction monosodium glutamate, 25 % mass
768 glutamate
(optional) fraction 5′- guanylic acid, 25 % mass fraction inosinic
(0,06 % mass fraction)
acid) + 1 l water with 0,5 g NaCl
418 Water water
Candidates are graded according to performance on the scale shown in Table 7.
Table 7 — Gradation scale I
Points Result
6 all correct
5 five correct
4 four correct
3 three correct
2 two correct
1 one correct
0 none correct
5.3.4 Ranking tests
A minimum of four test samples should be ranked in order of increasing intensity. This test will indicate
whether the assessor can tell the difference between samples for certain basic tastes.
Samples for ranking of sweetness, sourness, saltiness, bitterness and creamy flavour are given in
Tables 8, 9, 10, 11 and 12, respectively.
This test can also indicate the threshold levels of assessors (i.e. if the assessor did not correctly identify
the order of the lower intensities, that would indicate that this assessor cannot taste at lower levels for
this particular attribute).
NOTE All samples are randomized, but are presented to all the assessors in the same order.
Table 8 — Sweet ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
478 3 10 g/l sucrose (1 % mass per volume) 10 g sucrose + 1 l water
753 1 Water Water
578 4 15 g/l sucrose (1,5 % mass per volume) 15 g sucrose + 1 l water
248 2 5 g/l sucrose (0,5 % mass per volume) 5 g sucrose + 1 l water
IDF 99-1:2023(E)
Table 9 — Sour ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
145 2 0,10 g/l citric acid (0,01 % mass per vol- 0,10 g citric
ume) acid + 1 l water
249 4 0,5 g/l citric acid (0,05 % mass per volume) 0,5 g citric
acid + 1 l water
871 1 Water Water
675 3 0,3 g/l citric acid (0,03 % mass per volume) 0,3 g citric
acid + 1 l water
Table 10 — Salt ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
985 2 1 g/l NaCl (0,1 % mass per volume) 1 g NaCl + 1 l water
813 1 Water Water
713 4 2 g/l NaCl (0,2 % mass per volume) 2 g NaCl + 1 l water
632 3 1,5 g/l NaCl (0,15 % mass per volume) 1,5 g NaCl + 1 l water
Table 11 — Bitter ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
268 2 0,1 g/l caffeine (0,01 % mass per volume) 0,1 g caffeine + 1 l water
634 1 Water Water
919 4 0,5 g/l caffeine (0,05 % mass per volume) 0,5 g caffeine + 1 l water
752 3 0,3 g/l caffeine (0,03 % mass per volume) 0,3 g caffeine + 1 l water
Table 12 — Creamy flavour ranking
Blind code (examples) Correct ranking Sample preparation
268 1 Ultra high temperature (UHT) non-fat
634 4 UHT full fat + 20 % volume fraction UHT cream
919 3 UHT full fat + 3 % volume fraction UHT cream
752 2 UHT full fat
Candidates are graded according to performance on the scale shown in Table 13.
Table 13 — Gradation scale II
Points Result
4 Four correct
3 Adjacent switch
1 One correct
0 None correct
5.3.5 Difference testing
Difference testing indicates if the individual can detect small differences between samples for certain
flavours or textures.
IDF 99-1:2023(E)
The test samples should be selected so that they test the capability of the assessor to discriminate
between the samples based only on flavour or texture. An expert assessor can
...
SLOVENSKI STANDARD
01-junij-2024
Mleko in mlečni izdelki - Senzorična analiza - 1. del: Novačenje, izbira,
usposabljanje in spremljanje ocenjevalcev (ISO 22935-1:2023)
Milk and milk products — Sensory analysis — Part 1: Recruitment, selection, training
and monitoring of assessors (ISO 22935-1:2023)
Lait et produits laitiers — Analyse sensorielle — Partie 1: Recrutement, sélection,
entraînement et contrôle des sujets (ISO 22935-1:2023)
Ta slovenski standard je istoveten z: ISO 22935-1:2023
ICS:
03.100.30 Vodenje ljudi Management of human
resources
67.100.01 Mleko in mlečni proizvodi na Milk and milk products in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
INTERNATIONAL ISO
STANDARD 22935-1
IDF 99-1
Second edition
2023-04
Milk and milk products — Sensory
analysis —
Part 1:
Recruitment, selection, training and
monitoring of assessors
Lait et produits laitiers — Analyse sensorielle —
Partie 1: Recrutement, sélection, entraînement et contrôle des sujets
Reference numbers
IDF 99-1:2023(E)
IDF 99-1:2023(E)
© ISO and IDF 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office International Dairy Federation
CP 401 • Ch. de Blandonnet 8 Silver Building • Bd Auguste Reyers 70/B
CH-1214 Vernier, Geneva B-1030 Brussels
Phone: +41 22 749 01 11 Phone: +32 2 325 67 40
Fax: +32 2 325 67 41
Email: copyright@iso.org Email: info@fil-idf.org
Website: www.iso.org Website: www.fil-idf.org
Published in Switzerland
ii
IDF 99-1:2023(E)
Contents Page
Forewords .iv
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Recruitment . 2
5 Screening. 2
5.1 Screening form and requirements . 2
5.2 Preparation of test samples for screening . 3
5.3 Screening tests, materials and methods . 4
5.3.1 General . 4
5.3.2 Odour recognition . 4
5.3.3 Basic taste recognition . 4
5.3.4 Ranking tests . 5
5.3.5 Difference testing . 6
5.3.6 Descriptive ability and group discussion . 9
5.3.7 Marking schedule summary . . 10
6 Selection .11
7 Requirements for assessors in the panel .12
8 Training and monitoring of assessors for dairy products .12
8.1 General .12
8.2 References. 13
9 Performance .16
Bibliography .17
iii
IDF 99-1:2023(E)
Forewords
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 of 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
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5,
Milk and milk products, and the International Dairy Federation (IDF). It is being published jointly by ISO
and IDF.
This second edition cancels and replaces the first edition (ISO 22935-1 | IDF 99-1:2009), which has been
technically revised.
The main changes are as follows:
— the Normative references have been updated;
— a few changes have been made to reference materials.
A list of all parts in the ISO 22935 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
IDF 99-1:2023(E)
IDF (the International Dairy Federation) is a non-profit private sector organization representing the
interests of various stakeholders in dairying at the global level. IDF members are organized in National
Committees, which are national associations composed of representatives of dairy-related national
interest groups including dairy farmers, dairy processing industry, dairy suppliers, academics and
governments/food control authorities.
ISO and IDF collaborate closely on all matters of standardization relating to methods of analysis
and sampling for milk and milk products. Since 2001, ISO and IDF jointly publish their International
Standards using the logos and reference numbers of both organizations.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. IDF 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.
This document was prepared by the IDF Standing Committee on Statistics and Automation and ISO
Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is being
published jointly by ISO and IDF.
The work was carried out by the IDF/ISO Action Team S17 of the Standing Committee on Statistics and
Automation under the aegis of its project leader Dr H. Kraggerud (NO).
v
IDF 99-1:2023(E)
Introduction
The purpose of the ISO 22935 | IDF 99 series is to give guidance on methodology for sensory analysis
and the use of a common nomenclature of terms for milk and milk products.
To achieve that, the ISO 22935 | IDF 99 series is divided into three parts.
ISO 6658 should be consulted for an overview of sensory methods other than the one provided in
ISO 22935-3 | IDF 99-3.
The principles described are largely derived from various International Standards on the topic.
It is important that safety issues are handled during sensory evaluations (see ISO 20613).
vi
INTERNATIONAL STANDARD
IDF 99-1:2023(E)
Milk and milk products — Sensory analysis —
Part 1:
Recruitment, selection, training and monitoring of
assessors
1 Scope
This document gives general guidance for the recruitment, selection, training, and monitoring of
assessors for sensory analysis of milk and milk products.
It specifies criteria for the selection, and procedures for the training and monitoring, of selected
assessors and expert sensory assessors for milk and milk products. It supplements the information
given in ISO 8586 that deals with expert assessors.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4120, Sensory analysis — Methodology — Triangle test
ISO 4121, Sensory analysis — Guidelines for the use of quantitative response scales
ISO 5492, Sensory analysis — Vocabulary
ISO 5496, Sensory analysis — Methodology — Initiation and training of assessors in the detection and
recognition of odours
ISO 6658, Sensory analysis — Methodology — General guidance
ISO 8586:2012, Sensory analysis — General guidelines for the selection, training and monitoring of selected
assessors and expert sensory assessors
ISO 8587, Sensory analysis — Methodology — Ranking
ISO 8589, Sensory analysis — General guidance for the design of test rooms
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4121, ISO 5492, ISO 5496,
ISO 6658, ISO 8586 and ISO 8589 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
IDF 99-1:2023(E)
3.1
sensory analysis
science involved with the assessment of the sensory attributes of a product by the senses
[SOURCE: ISO 5492:2008, 1.1, modified — “sensory” replaced “organoleptic” in the definition.]
3.2
expert sensory assessor
selected assessor with a demonstrated sensory sensitivity and with considerable training and
experience in sensory testing, who is able to make consistent and repeatable sensory assessments of
various products
Note 1 to entry: Examples of “various products” are “dairy products”.
[SOURCE: ISO 5492:2008, 1.8, modified — Note 1 to entry added.]
3.3
appearance
all the visible attributes of a substance or object
Note 1 to entry: For a dairy product, the visual attributes are both internal and external, and include shape,
colour, loose liquid, phase separation, wanted or unwanted particles, and openings.
[SOURCE: ISO 5492:2008, 3.1, modified — Note 1 to entry added.]
3.4
fingerfeel
mixed experience derived from sensations on the fingers that relate to physical properties of a stimulus
3.5
flavour
complex combination of the olfactory, gustatory and trigeminal sensations perceived during tasting
[SOURCE: ISO 5492:2008, 3.20, modified — Note 1 to entry deleted.]
4 Recruitment
Assessors can be recruited from within a company (laboratory staff, production staff, administration
staff, etc.), who are not involved with project work, or from outside a company. Outside assessors can be
recruited by advertisement or by word of mouth. The panel candidates should have an understanding
of the amount of time that will be required for the screening process and for actual panel work. A large
enough pool of available candidates should be screened in order to have enough assessors available to
select from when forming a panel. The trainee assessor should have satisfactory personal qualifications
for assessments and should be pre-selected by:
a) the use of screening tests to assess the ability of candidates to perceive, discriminate and describe
sensory attributes;
b) a general understanding of the concepts of sensory evaluation;
c) a general liking or interest in dairy products.
5 Screening
5.1 Screening form and requirements
Potential applicants should go through two forms of screening via an interview and sensory screening
tests. During the interview, the applicants should fill out a pre-screening form which indicates the times
that they are available for panels and any health issues they can have, e.g. arthritis which can interfere
IDF 99-1:2023(E)
with the evaluation of product texture in-hand (fingerfeel), lactose intolerance, food allergies, wearing
of dentures, smoking status, and any other issues of concern.
Flavoured water solutions and dairy products should be used to indicate if the potential assessor can
recognize specific tastes or flavours at different intensities. The potential evaluator shall be able to
detect certain flavours within complex dairy products. The following three sessions each take assessors
approximately 45 min to 1 h to complete. These screening exercises are suggestions only and may be
adapted to the application area of the assessors. The sessions described in Tables 1 to 3 may be broken
down into smaller or larger sessions depending on how much time is available.
Table 1 — Session 1 — Basic odour and taste recognition
Test Reference Result
1 5.3.2 Odour recognition
2 5.3.3 Basic taste recognition
3 5.3.4, Table 8 Ranking of basic taste — sweet
4 5.3.4, Table 9 Ranking of basic taste — sour
5 5.3.4, Table 10 Ranking of basic taste — salty
6 5.3.4, Table 11 Ranking of basic taste — bitter
Table 2 — Session 2 — Milk powder and cream products
Test Reference Result
7 5.3.5, Table 14 Triangle test — milk powder
8 5.3.5, Table 15 Triangle test — butter
9 5.3.5, Table 16 Triangle test — salted butter
10 5.3.6.3 Round table discussion — cream evaluation
11 5.3.4, Table 12 Ranking of texture — body/creaminess
12 5.3.5, Table 13 Triangle test — aged milk powder
Table 3 — Session 3 — Cheese
Test Reference Result
13 5.3.5, Table 16 Triangle test — cheese
14 5.3.6.2 Round table discussion — cheese evaluation
15 5.3.5, Table 16 Triangle test — bitter cheese
16 5.3.5, Table 17 Triangle test — cheese firmness
17 5.3.5, Table 17 Triangle test — cheese smoothness
Mark each section as per each marking schedule. Other examples of screening exercises can be found in
ISO 8586.
5.2 Preparation of test samples for screening
5.2.1 If possible, prepare test samples on the day of the evaluation.
5.2.2 For screening purposes, it is easier to serve test samples in the same order to all assessors.
5.2.3 If appropriate, use test sample questionnaires for all screening exercises found in ISO 4120
(triangle test), ISO 8587 (ranking test), ISO 6658 and ISO 4121 (scales).
IDF 99-1:2023(E)
5.3 Screening tests, materials and methods
5.3.1 General
The screening tests, materials and methods presented in this clause are recommendations only. They
can be adapted to suit the needs of an individual company.
5.3.2 Odour recognition
Follow the instructions outlined in ISO 8586:2012, 5.4.1, for details on how to prepare the test samples
and conduct this test. Table 4 suggests other aromas that can be used.
Table 4 — Examples of olfactory materials for odour description test
Blind code Sample preparation
(example)
981 Citronella oil (lemon, cleaning fluid)
194 Orange
229 Caramel
371 Butyric acid
926 Acetic acid
174 Ammonia
a
746 (Z)-hex-3-en-1-ol
831 Oct-1-en-3-ol
556 Vanilla
a
In older literature, known as cis-hex-3-en-1-ol.
Candidates are graded according to performance, as shown in Table 5. For each sample, a total of three
points can be achieved. If the assessor uses words other than those listed in Table 5, score appropriately.
Table 5 — Marking schedule for odour recognition
Correct answer
Sample
3 points 2 points 1 point
Citronella oil Citronella oil Lemony, cleaning fluid Citrus, fruity
Orange Orange Lemon Citrus, fruity
Caramel Caramel Vanilla, malt, toasted Sweet
Butyric acid Rancid butter Parmesan cheese Vomit, baby burp
Acetic acid Acetic acid Vinegar Sour/off milk
Ammonia Ammonia Cleaning fluid, urine Pungent
(Z)-hex-3-en-1-ol Green grass Green beans Green vegetable
Oct-1-en-3-ol Mushroom Cellar, musty Mouldy
Vanilla Vanilla Custard, dessert Sweets, candy
5.3.3 Basic taste recognition
The solutions can be prepared as shown in Table 6. Present the solutions to the assessors in the same
order, and one of the solutions twice. Ask the assessor to identify the basic taste that is represented by
the solution.
IDF 99-1:2023(E)
Table 6 — Basic taste solutions
Blind code Answer Concentration Sample preparation
(examples)
10 g/l sucrose
683 Sweet 10 g sucrose + 1 l water
(1 % mass fraction)
2 g/l NaCl
429 Salty 2 g NaCl + 1 l water
(0,2 % mass fraction)
0,3 g/l citric acid
662 Sour 0,3 g citric acid + 1 l water
(0,03 % mass fraction)
0,3 g/l caffeine
353 Bitter 0,3 g caffeine + 1 l water
(0,03 % mass fraction)
0,6 g monosodium glutamate or 0,18 g umami mixture
0,6 g/l monosodium
Umami (50 % mass fraction monosodium glutamate, 25 % mass
768 glutamate
(optional) fraction 5′- guanylic acid, 25 % mass fraction inosinic
(0,06 % mass fraction)
acid) + 1 l water with 0,5 g NaCl
418 Water water
Candidates are graded according to performance on the scale shown in Table 7.
Table 7 — Gradation scale I
Points Result
6 all correct
5 five correct
4 four correct
3 three correct
2 two correct
1 one correct
0 none correct
5.3.4 Ranking tests
A minimum of four test samples should be ranked in order of increasing intensity. This test will indicate
whether the assessor can tell the difference between samples for certain basic tastes.
Samples for ranking of sweetness, sourness, saltiness, bitterness and creamy flavour are given in
Tables 8, 9, 10, 11 and 12, respectively.
This test can also indicate the threshold levels of assessors (i.e. if the assessor did not correctly identify
the order of the lower intensities, that would indicate that this assessor cannot taste at lower levels for
this particular attribute).
NOTE All samples are randomized, but are presented to all the assessors in the same order.
Table 8 — Sweet ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
478 3 10 g/l sucrose (1 % mass per volume) 10 g sucrose + 1 l water
753 1 Water Water
578 4 15 g/l sucrose (1,5 % mass per volume) 15 g sucrose + 1 l water
248 2 5 g/l sucrose (0,5 % mass per volume) 5 g sucrose + 1 l water
IDF 99-1:2023(E)
Table 9 — Sour ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
145 2 0,10 g/l citric acid (0,01 % mass per vol- 0,10 g citric
ume) acid + 1 l water
249 4 0,5 g/l citric acid (0,05 % mass per volume) 0,5 g citric
acid + 1 l water
871 1 Water Water
675 3 0,3 g/l citric acid (0,03 % mass per volume) 0,3 g citric
acid + 1 l water
Table 10 — Salt ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
985 2 1 g/l NaCl (0,1 % mass per volume) 1 g NaCl + 1 l water
813 1 Water Water
713 4 2 g/l NaCl (0,2 % mass per volume) 2 g NaCl + 1 l water
632 3 1,5 g/l NaCl (0,15 % mass per volume) 1,5 g NaCl + 1 l water
Table 11 — Bitter ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
268 2 0,1 g/l caffeine (0,01 % mass per volume) 0,1 g caffeine + 1 l water
634 1 Water Water
919 4 0,5 g/l caffeine (0,05 % mass per volume) 0,5 g caffeine + 1 l water
752 3 0,3 g/l caffeine (0,03 % mass per volume) 0,3 g caffeine + 1 l water
Table 12 — Creamy flavour ranking
Blind code (examples) Correct ranking Sample preparation
268 1 Ultra high temperature (UHT) non-fat
634 4 UHT full fat + 20 % volume fraction UHT cream
919 3 UHT full fat + 3 % volume fraction UHT cream
752 2 UHT full fat
Candidates are graded according to performance on the scale shown in Table 13.
Table 13 — Gradation scale II
Points Result
4 Four correct
3 Adjacent switch
1 One correct
0 None correct
5.3.5 Difference testing
Difference testing indicates if the individual can detect small differences between samples for certain
flavours or textures.
IDF 99-1:2023(E)
The test samples should be selected so that they test the capability of the assessor to discriminate
between the samples based only on flavour or texture. An expert assessor c
...
INTERNATIONAL ISO
STANDARD 22935-1
IDF 99-1
Second edition
2023-04
Milk and milk products — Sensory
analysis —
Part 1:
Recruitment, selection, training and
monitoring of assessors
Lait et produits laitiers — Analyse sensorielle —
Partie 1: Recrutement, sélection, entraînement et contrôle des sujets
Reference numbers
IDF 99-1:2023(E)
IDF 99-1:2023(E)
© ISO and IDF 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office International Dairy Federation
CP 401 • Ch. de Blandonnet 8 Silver Building • Bd Auguste Reyers 70/B
CH-1214 Vernier, Geneva B-1030 Brussels
Phone: +41 22 749 01 11 Phone: +32 2 325 67 40
Fax: +32 2 325 67 41
Email: copyright@iso.org Email: info@fil-idf.org
Website: www.iso.org Website: www.fil-idf.org
Published in Switzerland
ii
IDF 99-1:2023(E)
Contents Page
Forewords .iv
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Recruitment . 2
5 Screening. 2
5.1 Screening form and requirements . 2
5.2 Preparation of test samples for screening . 3
5.3 Screening tests, materials and methods . 4
5.3.1 General . 4
5.3.2 Odour recognition . 4
5.3.3 Basic taste recognition . 4
5.3.4 Ranking tests . 5
5.3.5 Difference testing . 6
5.3.6 Descriptive ability and group discussion . 9
5.3.7 Marking schedule summary . . 10
6 Selection .11
7 Requirements for assessors in the panel .12
8 Training and monitoring of assessors for dairy products .12
8.1 General .12
8.2 References. 13
9 Performance .16
Bibliography .17
iii
IDF 99-1:2023(E)
Forewords
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 of 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
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5,
Milk and milk products, and the International Dairy Federation (IDF). It is being published jointly by ISO
and IDF.
This second edition cancels and replaces the first edition (ISO 22935-1 | IDF 99-1:2009), which has been
technically revised.
The main changes are as follows:
— the Normative references have been updated;
— a few changes have been made to reference materials.
A list of all parts in the ISO 22935 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
IDF 99-1:2023(E)
IDF (the International Dairy Federation) is a non-profit private sector organization representing the
interests of various stakeholders in dairying at the global level. IDF members are organized in National
Committees, which are national associations composed of representatives of dairy-related national
interest groups including dairy farmers, dairy processing industry, dairy suppliers, academics and
governments/food control authorities.
ISO and IDF collaborate closely on all matters of standardization relating to methods of analysis
and sampling for milk and milk products. Since 2001, ISO and IDF jointly publish their International
Standards using the logos and reference numbers of both organizations.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. IDF 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.
This document was prepared by the IDF Standing Committee on Statistics and Automation and ISO
Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is being
published jointly by ISO and IDF.
The work was carried out by the IDF/ISO Action Team S17 of the Standing Committee on Statistics and
Automation under the aegis of its project leader Dr H. Kraggerud (NO).
v
IDF 99-1:2023(E)
Introduction
The purpose of the ISO 22935 | IDF 99 series is to give guidance on methodology for sensory analysis
and the use of a common nomenclature of terms for milk and milk products.
To achieve that, the ISO 22935 | IDF 99 series is divided into three parts.
ISO 6658 should be consulted for an overview of sensory methods other than the one provided in
ISO 22935-3 | IDF 99-3.
The principles described are largely derived from various International Standards on the topic.
It is important that safety issues are handled during sensory evaluations (see ISO 20613).
vi
INTERNATIONAL STANDARD
IDF 99-1:2023(E)
Milk and milk products — Sensory analysis —
Part 1:
Recruitment, selection, training and monitoring of
assessors
1 Scope
This document gives general guidance for the recruitment, selection, training, and monitoring of
assessors for sensory analysis of milk and milk products.
It specifies criteria for the selection, and procedures for the training and monitoring, of selected
assessors and expert sensory assessors for milk and milk products. It supplements the information
given in ISO 8586 that deals with expert assessors.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4120, Sensory analysis — Methodology — Triangle test
ISO 4121, Sensory analysis — Guidelines for the use of quantitative response scales
ISO 5492, Sensory analysis — Vocabulary
ISO 5496, Sensory analysis — Methodology — Initiation and training of assessors in the detection and
recognition of odours
ISO 6658, Sensory analysis — Methodology — General guidance
ISO 8586:2012, Sensory analysis — General guidelines for the selection, training and monitoring of selected
assessors and expert sensory assessors
ISO 8587, Sensory analysis — Methodology — Ranking
ISO 8589, Sensory analysis — General guidance for the design of test rooms
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4121, ISO 5492, ISO 5496,
ISO 6658, ISO 8586 and ISO 8589 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
IDF 99-1:2023(E)
3.1
sensory analysis
science involved with the assessment of the sensory attributes of a product by the senses
[SOURCE: ISO 5492:2008, 1.1, modified — “sensory” replaced “organoleptic” in the definition.]
3.2
expert sensory assessor
selected assessor with a demonstrated sensory sensitivity and with considerable training and
experience in sensory testing, who is able to make consistent and repeatable sensory assessments of
various products
Note 1 to entry: Examples of “various products” are “dairy products”.
[SOURCE: ISO 5492:2008, 1.8, modified — Note 1 to entry added.]
3.3
appearance
all the visible attributes of a substance or object
Note 1 to entry: For a dairy product, the visual attributes are both internal and external, and include shape,
colour, loose liquid, phase separation, wanted or unwanted particles, and openings.
[SOURCE: ISO 5492:2008, 3.1, modified — Note 1 to entry added.]
3.4
fingerfeel
mixed experience derived from sensations on the fingers that relate to physical properties of a stimulus
3.5
flavour
complex combination of the olfactory, gustatory and trigeminal sensations perceived during tasting
[SOURCE: ISO 5492:2008, 3.20, modified — Note 1 to entry deleted.]
4 Recruitment
Assessors can be recruited from within a company (laboratory staff, production staff, administration
staff, etc.), who are not involved with project work, or from outside a company. Outside assessors can be
recruited by advertisement or by word of mouth. The panel candidates should have an understanding
of the amount of time that will be required for the screening process and for actual panel work. A large
enough pool of available candidates should be screened in order to have enough assessors available to
select from when forming a panel. The trainee assessor should have satisfactory personal qualifications
for assessments and should be pre-selected by:
a) the use of screening tests to assess the ability of candidates to perceive, discriminate and describe
sensory attributes;
b) a general understanding of the concepts of sensory evaluation;
c) a general liking or interest in dairy products.
5 Screening
5.1 Screening form and requirements
Potential applicants should go through two forms of screening via an interview and sensory screening
tests. During the interview, the applicants should fill out a pre-screening form which indicates the times
that they are available for panels and any health issues they can have, e.g. arthritis which can interfere
IDF 99-1:2023(E)
with the evaluation of product texture in-hand (fingerfeel), lactose intolerance, food allergies, wearing
of dentures, smoking status, and any other issues of concern.
Flavoured water solutions and dairy products should be used to indicate if the potential assessor can
recognize specific tastes or flavours at different intensities. The potential evaluator shall be able to
detect certain flavours within complex dairy products. The following three sessions each take assessors
approximately 45 min to 1 h to complete. These screening exercises are suggestions only and may be
adapted to the application area of the assessors. The sessions described in Tables 1 to 3 may be broken
down into smaller or larger sessions depending on how much time is available.
Table 1 — Session 1 — Basic odour and taste recognition
Test Reference Result
1 5.3.2 Odour recognition
2 5.3.3 Basic taste recognition
3 5.3.4, Table 8 Ranking of basic taste — sweet
4 5.3.4, Table 9 Ranking of basic taste — sour
5 5.3.4, Table 10 Ranking of basic taste — salty
6 5.3.4, Table 11 Ranking of basic taste — bitter
Table 2 — Session 2 — Milk powder and cream products
Test Reference Result
7 5.3.5, Table 14 Triangle test — milk powder
8 5.3.5, Table 15 Triangle test — butter
9 5.3.5, Table 16 Triangle test — salted butter
10 5.3.6.3 Round table discussion — cream evaluation
11 5.3.4, Table 12 Ranking of texture — body/creaminess
12 5.3.5, Table 13 Triangle test — aged milk powder
Table 3 — Session 3 — Cheese
Test Reference Result
13 5.3.5, Table 16 Triangle test — cheese
14 5.3.6.2 Round table discussion — cheese evaluation
15 5.3.5, Table 16 Triangle test — bitter cheese
16 5.3.5, Table 17 Triangle test — cheese firmness
17 5.3.5, Table 17 Triangle test — cheese smoothness
Mark each section as per each marking schedule. Other examples of screening exercises can be found in
ISO 8586.
5.2 Preparation of test samples for screening
5.2.1 If possible, prepare test samples on the day of the evaluation.
5.2.2 For screening purposes, it is easier to serve test samples in the same order to all assessors.
5.2.3 If appropriate, use test sample questionnaires for all screening exercises found in ISO 4120
(triangle test), ISO 8587 (ranking test), ISO 6658 and ISO 4121 (scales).
IDF 99-1:2023(E)
5.3 Screening tests, materials and methods
5.3.1 General
The screening tests, materials and methods presented in this clause are recommendations only. They
can be adapted to suit the needs of an individual company.
5.3.2 Odour recognition
Follow the instructions outlined in ISO 8586:2012, 5.4.1, for details on how to prepare the test samples
and conduct this test. Table 4 suggests other aromas that can be used.
Table 4 — Examples of olfactory materials for odour description test
Blind code Sample preparation
(example)
981 Citronella oil (lemon, cleaning fluid)
194 Orange
229 Caramel
371 Butyric acid
926 Acetic acid
174 Ammonia
a
746 (Z)-hex-3-en-1-ol
831 Oct-1-en-3-ol
556 Vanilla
a
In older literature, known as cis-hex-3-en-1-ol.
Candidates are graded according to performance, as shown in Table 5. For each sample, a total of three
points can be achieved. If the assessor uses words other than those listed in Table 5, score appropriately.
Table 5 — Marking schedule for odour recognition
Correct answer
Sample
3 points 2 points 1 point
Citronella oil Citronella oil Lemony, cleaning fluid Citrus, fruity
Orange Orange Lemon Citrus, fruity
Caramel Caramel Vanilla, malt, toasted Sweet
Butyric acid Rancid butter Parmesan cheese Vomit, baby burp
Acetic acid Acetic acid Vinegar Sour/off milk
Ammonia Ammonia Cleaning fluid, urine Pungent
(Z)-hex-3-en-1-ol Green grass Green beans Green vegetable
Oct-1-en-3-ol Mushroom Cellar, musty Mouldy
Vanilla Vanilla Custard, dessert Sweets, candy
5.3.3 Basic taste recognition
The solutions can be prepared as shown in Table 6. Present the solutions to the assessors in the same
order, and one of the solutions twice. Ask the assessor to identify the basic taste that is represented by
the solution.
IDF 99-1:2023(E)
Table 6 — Basic taste solutions
Blind code Answer Concentration Sample preparation
(examples)
10 g/l sucrose
683 Sweet 10 g sucrose + 1 l water
(1 % mass fraction)
2 g/l NaCl
429 Salty 2 g NaCl + 1 l water
(0,2 % mass fraction)
0,3 g/l citric acid
662 Sour 0,3 g citric acid + 1 l water
(0,03 % mass fraction)
0,3 g/l caffeine
353 Bitter 0,3 g caffeine + 1 l water
(0,03 % mass fraction)
0,6 g monosodium glutamate or 0,18 g umami mixture
0,6 g/l monosodium
Umami (50 % mass fraction monosodium glutamate, 25 % mass
768 glutamate
(optional) fraction 5′- guanylic acid, 25 % mass fraction inosinic
(0,06 % mass fraction)
acid) + 1 l water with 0,5 g NaCl
418 Water water
Candidates are graded according to performance on the scale shown in Table 7.
Table 7 — Gradation scale I
Points Result
6 all correct
5 five correct
4 four correct
3 three correct
2 two correct
1 one correct
0 none correct
5.3.4 Ranking tests
A minimum of four test samples should be ranked in order of increasing intensity. This test will indicate
whether the assessor can tell the difference between samples for certain basic tastes.
Samples for ranking of sweetness, sourness, saltiness, bitterness and creamy flavour are given in
Tables 8, 9, 10, 11 and 12, respectively.
This test can also indicate the threshold levels of assessors (i.e. if the assessor did not correctly identify
the order of the lower intensities, that would indicate that this assessor cannot taste at lower levels for
this particular attribute).
NOTE All samples are randomized, but are presented to all the assessors in the same order.
Table 8 — Sweet ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
478 3 10 g/l sucrose (1 % mass per volume) 10 g sucrose + 1 l water
753 1 Water Water
578 4 15 g/l sucrose (1,5 % mass per volume) 15 g sucrose + 1 l water
248 2 5 g/l sucrose (0,5 % mass per volume) 5 g sucrose + 1 l water
IDF 99-1:2023(E)
Table 9 — Sour ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
145 2 0,10 g/l citric acid (0,01 % mass per vol- 0,10 g citric
ume) acid + 1 l water
249 4 0,5 g/l citric acid (0,05 % mass per volume) 0,5 g citric
acid + 1 l water
871 1 Water Water
675 3 0,3 g/l citric acid (0,03 % mass per volume) 0,3 g citric
acid + 1 l water
Table 10 — Salt ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
985 2 1 g/l NaCl (0,1 % mass per volume) 1 g NaCl + 1 l water
813 1 Water Water
713 4 2 g/l NaCl (0,2 % mass per volume) 2 g NaCl + 1 l water
632 3 1,5 g/l NaCl (0,15 % mass per volume) 1,5 g NaCl + 1 l water
Table 11 — Bitter ranking
Blind code Correct Concentration Sample preparation
(examples) ranking
268 2 0,1 g/l caffeine (0,01 % mass per volume) 0,1 g caffeine + 1 l water
634 1 Water Water
919 4 0,5 g/l caffeine (0,05 % mass per volume) 0,5 g caffeine + 1 l water
752 3 0,3 g/l caffeine (0,03 % mass per volume) 0,3 g caffeine + 1 l water
Table 12 — Creamy flavour ranking
Blind code (examples) Correct ranking Sample preparation
268 1 Ultra high temperature (UHT) non-fat
634 4 UHT full fat + 20 % volume fraction UHT cream
919 3 UHT full fat + 3 % volume fraction UHT cream
752 2 UHT full fat
Candidates are graded according to performance on the scale shown in Table 13.
Table 13 — Gradation scale II
Points Result
4 Four correct
3 Adjacent switch
1 One correct
0 None correct
5.3.5 Difference testing
Difference testing indicates if the individual can detect small differences between samples for certain
flavours or textures.
IDF 99-1:2023(E)
The test samples should be selected so that they test the capability of the assessor to discriminate
between the samples based only on flavour or texture. An expert assessor can be used to select the
samples to be used in the tests. Examples of samples for difference testing are listed in Table 14 to
Table 17.
“Paired comparison” or “triangle” testing should be conducted on a series of products. If the assessor
thinks the samples are different, they can be asked to indicate what the difference is. This indicates if
assessors can accurately identify differences between products and name the difference.
All test samples are to be presented to all assessors in the same randomized order.
It is recommended that each set of samples be presented to the assessors twi
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