1、BRITISH STANDARD BS EN ISO 10399:2010Sensory analysis Methodology Duo-trio testICS 67.240g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Incorporati
2、ng corrigendum April 2010National forewordThis British Standard is the UK implementation of EN ISO 10399:2010. It is identical to ISO 10399:2004. It supersedes BS ISO 10399:2004 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee AW/12, Sensory analysis.A
3、list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from le
4、gal obligations.BS EN ISO 10399:2010This British Standard was published under the authority of the Standards Policy and Strategy Committee on 2 July 2004 BSI 2010Amendments/corrigenda issued since publicationDate Comments 30 April 2010 This corrigenda renumbers BS ISO 10399:2004 as BS EN ISO 10399:2
5、010ISBN 978 0 580 69084 6EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 10399 February 2010 ICS 67.240 English Version Sensory analysis - Methodology - Duo-trio test (ISO 10399:2004) Analyse sensorielle - Mthodologie - Essai duo-trio (ISO 10399:2004) Sensorische Analyse - Prfverfahren - Du
6、o-Trio-Prfung (ISO 10399:2004) This European Standard was approved by CEN on 31 January 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-dat
7、e lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under th
8、e responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Gre
9、ece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Managem
10、ent Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 10399:2010: EForeword The text of ISO 10399:2004 has been prepared by Technical Committee ISO/TC 34 “Food products” of the Inter
11、national Organization for Standardization (ISO) and has been taken over as EN ISO 10399:2010. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2010, and conflicting national standards shall
12、be withdrawn at the latest by August 2010. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regul
13、ations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Mal
14、ta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 10399:2004 has been approved by CEN as a EN ISO 10399:2010 without any modification. BS EN ISO 10399:2010EN ISO 10399:2010 (E)iiiContents Page
15、 1 Scope 1 2 Normative references . 1 3 Terms and definitions. 2 4 Principle . 2 5 General test conditions and requirements. 3 6 Assessors 3 6.1 Qualification 3 6.2 Number of assessors 4 7 Procedure. 4 8 Analysis and interpretation of results 5 8.1 When testing for a difference 5 8.2 When testing fo
16、r similarity. 5 9 Test report 6 10 Precision and bias 6 Annex A (normative) Tables 7 Annex B (informative) Examples. 12 Bibliography . 19 BS EN ISO 10399:2010EN ISO 10399:2010 (E)This page deliberately set blank1Sensory analysis Methodology Duo-trio test 1 Scope This International Standard describes
17、 a procedure for determining whether a perceptible sensory difference or similarity exists between samples of two products. The method is a forced-choice procedure. The method is applicable whether a difference exists in a single sensory attribute or in several attributes. The method is statisticall
18、y less efficient than the triangle test (described in ISO 4120) but is easier to perform by the assessors. The method is applicable even when the nature of the difference is unknown i.e. it determines neither the size nor the direction of difference between samples, nor is there any indication of th
19、e attribute(s) responsible for the difference. The method is applicable only if the products are fairly homogeneous. The method is effective for a) determining that either a perceptible difference results (duo-trio testing for difference), or a perceptible difference does not result (duo-trio testin
20、g for similarity) when, for example, a change is made in ingredients, processing, packaging, handling or storage; b) or for selecting, training and monitoring assessors. Two forms of the method are described: the constant-reference technique, used when one product is familiar to the assessors (e.g.
21、a sample from regular production), and the balanced-reference technique, used when one product is not more familiar than the other. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies.
22、For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5492:1992, Sensory analysis Vocabulary ISO 8589:1988, Sensory analysis General guidance for the design of test rooms BS EN ISO 10399:2010EN ISO 10399:2010 (E)2 3 Terms and definitions For th
23、e purposes of this document, the terms and definitions given in ISO 5492 and the following apply. 3.1 alpha-risk -risk probability of concluding that a perceptible difference exists when one does not NOTE This is also known as Type I error, significance level or false positive rate. 3.2 beta-risk -r
24、isk probability of concluding that no perceptible difference exists when one does NOTE This is also known as Type II error or false negative rate. 3.3 difference situation in which samples can be distinguished based on their sensory properties NOTE The proportion of assessments in which a perceptibl
25、e difference is detected between the two products is given the symbol pd. 3.4 product material to be evaluated 3.5 sample unit of product prepared, presented and evaluated in the test 3.6 sensitivity general term used to summarize the performance characteristics of the test NOTE In statistical terms
26、, the sensitivity of the test is defined by the values of , and pd. 3.7 similarity situation in which any perceptible differences between the samples are so small that the products can be used interchangeably 3.8 triad those three samples given to an assessor in the duo-trio test NOTE In the duo-tri
27、o test, one sample is labelled as the reference, the other two are marked with different codes. One of the coded samples is the same product as the reference; the other coded sample is the other product in the test. 4 Principle The number of assessors is chosen based on the sensitivity desired for t
28、he test. (See 6.2 and the discussion in A.3.) Assessors receive a set of three samples (i.e. a triad), one sample of which is labelled as a reference and the other two samples have different codes. The assessors are informed that one of the coded samples is the BS EN ISO 10399:2010EN ISO 10399:2010
29、(E)3same as the reference and that one is different. Based on their training and the instructions given prior to the test, the assessors report either which of the coded samples they believe to be same as the reference, or which of the coded samples they believe to be different from the reference. T
30、he number of correct responses is counted and the significance is determined by reference to a statistical table. 5 General test conditions and requirements 5.1 Clearly define the test objective in writing. 5.2 Carry out the test under conditions that prevent communication among assessors until all
31、the evaluations have been completed using facilities and booths that comply with ISO 8589. 5.3 Prepare the samples out of sight of the assessors and in an identical manner (i.e. same apparatus, same vessels, same quantity of product). 5.4 Assessors shall not be able to identify the samples from the
32、way in which they are presented. For example, in a taste test, avoid any differences in appearance. Mask any irrelevant colour differences using light filters and/or subdued illumination. 5.5 Code the vessels containing the samples in a uniform manner, preferably using three-digit numbers, chosen at
33、 random for each test. Each triad is composed of three samples, one labelled as the reference and two labelled with different codes. Preferably, different codes should be used for each assessor during a session. However, the same two codes may be used for all assessors within a test, provided that e
34、ach code is used only once per assessor during a test session (e.g., if several duo-trio tests on different products are being conducted in the same session). 5.6 The quantity or volume served shall be identical for the three samples in each triad, just as that of all the other samples in a series o
35、f tests on a given type of product. The quantity or volume to be evaluated may be imposed. If it is not, the assessors should be told to take quantities or volumes that are always similar whatever the sample. 5.7 The temperature of the three samples in each triad shall be identical, just as that of
36、all the other samples in a series of tests on a given type of product. It is preferable to present the samples at the temperature at which the product is generally consumed. 5.8 The assessors shall be told whether or not they are to swallow the samples or whether they are free to do as they please.
37、In this latter case, they shall be requested to proceed in the same manner for all samples. 5.9 During the test sessions, avoid giving information about product identity, expected treatment effects, or individual performance until all testing is completed. 6 Assessors 6.1 Qualification All assessors
38、 should possess the same level of qualification, this level being chosen on the basis of the test objective (see ISO 8586-1 and ISO 8586-2 for guidance). Experience and familiarity with the product may improve the performance of an assessor and, therefore, may increase the likelihood of finding a si
39、gnificant difference. Monitoring the performance of assessors over time may be useful for increased sensitivity. All assessors shall be familiar with the mechanics of the duo-trio test (i.e. the format, task and evaluation procedure). BS EN ISO 10399:2010EN ISO 10399:2010 (E)4 6.2 Number of assessor
40、s Choose the number of assessors so as to obtain the sensitivity required for the test (see discussion in A.3). Using large numbers of assessors increases the likelihood of detecting small differences between the products. However, in practice, the number of assessors often is determined by material
41、 conditions (e.g. duration of the experiment, number of available assessors, quantity of product). When testing for a difference, typical numbers of assessors are between 32 and 36. When testing for no meaningful difference (i.e. similarity), twice as many assessors (i.e. approximately 72) are neede
42、d for equivalent sensitivity. Avoid replicate evaluations by the same assessor whenever possible. However, if replicate evaluations are needed to produce a sufficient number of total evaluations, every effort should be made to have each assessor perform the same number of replicate evaluations. For
43、example, if only twelve assessors are available, have each assessor evaluate three triads to obtain a total of 36 evaluations. NOTE Treating three evaluations performed by twelve assessors as 36 independent evaluations is not valid when testing for similarity using Table A.2. However, the test for d
44、ifference using Table A.1 is valid even when replicate evaluations are performed (see 9 and 10). Recent publications (see 7 and 8) on replicated discrimination tests suggest alternative approaches for analysing replicated evaluations in discrimination tests. 7 Procedure 7.1 If the product is familia
45、r to the assessors (e.g. a control sample from the production line), use the constant reference technique. If neither product is more familiar than the other, use the balanced-reference technique a) Constant-reference technique: Prepare worksheets and scoresheets (see B.2) in advance of the test so
46、as to utilize an equal number of the two possible sequences of two products, A and B: A-REF AB A-REF BA Distribute these at random in groups of two among the assessors (i.e. use each sequence once among the first two assessors; use each sequence once again among the next two assessors, etc.) This wi
47、ll minimize the imbalance that results if the total number of assessors is not an even number. b) Balanced-reference technique: Prepare worksheets and scoresheets (see B.1) in advance of the test so as to utilize an equal number of the four possible sequences of two products, A and B: A-REF AB A-REF
48、 BA B-REF AB B-REF BA where the first two triads contain product A as the reference (i.e. A-REF) and the last two triads contain product B as the reference (i.e. B-REF). Distribute these at random in groups of four among the assessors (i.e. use each sequence once among the first group of four assess
49、ors; use each sequence once again among the next group of four assessors, etc.). This will minimize the imbalance that results if the total number of assessors is not a multiple of four. 7.2 Present the three samples of each triad simultaneously if possible, following the same spatial arrangement for each assessor (e.g. on a line to be sampled always from left to right, in a triangular array). Within the triad, assessors are generally allowed to make repeated evaluations of each sample as desired (if, of course, the nature of the product allows
