1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 3972:2011Sensory analysis Methodology Method of investigating sensitivity of tasteIncorporating Corrigendum August 2012WARNING This document does not purport to address al
2、l of the safety concerns, if any, associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use. BS ISO 3972:2011 BRITISH STANDARDNational forewordThis Brit
3、ish Standard is the UK implementation of ISO 3972:2011,The UK participation in its preparation was entrusted to Technical Committee AW/12, Sensory analysis.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include a
4、ll the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2013.ISBN 978 0 580 80436 6 ICS 67.240 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the author
5、ity of the Standards Policy and Strategy Committee on 30 November 2011. Amendments/corrigenda issued since publicationDate Text affected 31 January 2013 Implementation of ISO corrigendum August 2012: Warning added to title pagePublished by BSI Standards Limited 2013.incorporating corrigendum August
6、2012. It supersedes BS 5929-7:1992, which is withdrawn.Sensory analysis Methodology Method of investigating sensitivity of tasteAnalyse sensorielle Mthodologie Mthode dveil la sensibilit gustative ISO 2011Reference numberISO 3972:2011(E)Third edition2011-10-15ISO3972INTERNATIONAL STANDARDCOPYRIGHT P
7、ROTECTED DOCUMENT ISO 2011All rights reserved. Unless otherwise specified, 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 permission in writing from either ISO at the address below or ISOs
8、 member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in Switzerlandii ISO 2012BS ISO 3972:2011 ISO 3972:2011 (E)ForewordISO (the International Organization for Stan
9、dardization) 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
10、 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.International St
11、andards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an In
12、ternational Standard requires approval by at least 75 % of the member bodies casting a vote.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.ISO 3972 w
13、as prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 12, Sensory analysis.This third edition cancels and replaces the second edition (ISO 3972:1991), which has been technically revised.iii ISO 2012BS ISO 3972:2011 ISO 3972:2011 (E)INTERNATIONAL STANDARD Sensory analysis Metho
14、dology Method of investigating sensitivity of taste1 ScopeThis International Standard specifies a set of objective tests for familiarizing assessors with sensory analysis. The test methods specified can be useful to:a) teach assessors to recognize tastes and to distinguish between them (see Clause 8
15、);b) teach assessors to know and to familiarize themselves with different types of threshold tests (see Clause 9);c) make assessors aware of their own sensitivity of taste;d) enable test supervisors to carry out a preliminary categorization of assessors.The methods can also be used as a periodic mon
16、itor of the sensitivity of taste of assessors who are already members of sensory analysis panels.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest e
17、dition of the referenced document (including any amendments) applies.ISO 5492:2008, Sensory analysis VocabularyISO 6658, Sensory analysis Methodology General guidanceISO 8586, Sensory analysis General guidelines for the selection, training and monitoring of selected and expert assessorsISO 8589, Sen
18、sory analysis General guidance for the design of test rooms3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 5492 (in particular 3.1, 3.2, and 3.3) and the following apply.3.1stimulus thresholdminimum value of a sensory stimulus needed to give rise to a
19、 sensationNOTE 1 The term “threshold” is always used with a qualifying term.NOTE 2 The sensation need not be identified.ISO 5492:2008, 2.253.2recognition thresholdminimum physical intensity of a stimulus for which an assessor will assign the same descriptor each time it is presentedNOTE The term “th
20、reshold” is always used with a qualifying term.ISO 5492:2008, 2.261 ISO 2012BS ISO 3972:2011 ISO 3972:2011 (E)3.3difference thresholdvalue of the smallest perceptible difference in the physical intensity of a stimulusNOTE The term “threshold” is always used with a qualifying term.ISO 5492:2008, 2.27
21、3.4satiation thresholdminimum concentration of a sensory stimulus without a perception of an increasing concentrationNOTE The term “threshold” is always used with a qualifying term.4 Principle4.1 Identification of tastesReference substances, in a known order, corresponding to certain tastes, in the
22、form of aqueous solutions of given concentration are presented to each assessor. After each tasting, the taste is identified by the assessors and their assessments recorded.4.2 Familiarization with the different types of thresholdFor each taste, the appropriate reference substance is presented to ea
23、ch assessor, in the form of a series of dilutions of increasing concentration. After each tasting, the results are recorded by the assessors.5 ReagentsWARNING Persons using this International Standard should be familiar with normal laboratory practice. This International Standard does not purport to
24、 address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.5.1 Water, neutral, tasteless, still and odourless, preferably of known har
25、dness.For recognition of metallic sensation, demineralized water shall be used to avoid oxidation and to get a metallic sensation. In demineralized water and water with a low hardness (spring water), a bitter and sour taste shows lower recognition thresholds.The water provided to the assessors for r
26、insing their mouths shall be identical with that used to prepare the dilutions (5.3).5.2 Stock solutions.Prepare, in volumetric flasks (6.1), the solutions listed in Table 1 from food-grade reference substances.5.3 Dilutions.From the stock solutions specified in Table 1, prepare a series of solution
27、s for each taste in accordance with Table 2.6 Apparatus6.1 One-mark volumetric flasks, ISO 10423, clean, dry and of suitable capacity for preparing the stock solutions.2 ISO 2012BS ISO 3972:2011 ISO 3972:2011 (E)6.2 Burettes, ISO 3851, preferably having automatic zeroing, for preparing the dilutions
28、, or pipettes, ISO 6482.6.3 Vessels (glasses, beakers), clean, dry, capacity of about 50 ml, for presentation of the test solutions.Table 1 Specification of the test solutionsTaste Reference substanceaCAS-Numbers Concentrationg/lAcid Citric acidb77-92-9 1,20Bitter Caffeinebc58-08-2 0,54Salty Sodium
29、chloride 7647-14-5 4,00Sweet Sucrosed57-50-1 24,00Umami Monosodium glutamate monohydrate 6106-04-3 2,00MetalliceIron(II) sulfate heptahydratef7782-63-0 0,012The requirements of national regulations concerning authorized products and particularly for food grade safety certification shall be taken int
30、o account.NOTE A quantity of 2 l of stock solution is sufficient for about 20 assessors.The substances are in accordance with EU Food Law.a The products used shall be free from impurities which could give interfering tastes.b This substance has a better recognition in spring and demineralized water.
31、c Caffeine should be dissolved in hot (80 C) water.d Sucrose solution is unstable, should be used within 24 h and should be stored chilled until use.e Perception can be modified by the condition of the teeth since certain dental prostheses produce an electrolytic effect.f Iron has to be dissolved on
32、ly in demineralized water for recognition and to avoid oxidation and colouring. Colouration of the solution is a sign of oxidation. Coloured iron solution shall therefore not be used for investigation sensitivity of taste.Table 2 Preparation of the solutions for each tasteDilutionAcid Bitter Salty S
33、weet Umami MetallicVmlg/lVmlg/lVmlg/lVmlg/lVmlg/lVmlg/l1mg/lD1 500 0,60 500 0,27 500 2,00 500 12,00 500 1,00 500 0,006 0 6,0D2 400 0,48 400 0,22 350 1,40 300 7,20 350 0,70 350 0,004 2 4,2D3 320 0,38 320 0,17 245 0,98 180 4,32 245 0,49 245 0,002 9 2,9D4 256 0,31 256 0,14 172 0,69 108 2,59 172 0,34 17
34、2 0,002 0 2,0D5 205 0,25 205 0,11 120 0,48 65 1,56 120 0,24 120 0,001 4 1,4D6 164 0,20 164 0,09 84 0,34 39 0,94 84 0,17 84 0,001 0 1,0D7 131 0,16 131 0,07 59 0,24 23 0,55 59 0,12 59 0,000 8 0,8D8 105 0,13 105 0,06 41 0,16 14 0,34 41 0,08 41 0,000 5 0,5Geometrical ratio RR = 0,8 R = 0,8 R = 0,7 R = 0
35、,6 R = 0,7 R = 0,7V is the quantity of the stock solution taken, in millilitres, for 1 l of final solution; is the concentration of the dilution, in grams per litre;1is the concentration of the dilution, in milligrams per litre.3 ISO 2012BS ISO 3972:2011 ISO 3972:2011 (E)7 General test conditions7.1
36、 Test roomThe tests shall be conducted in a room which complies with the requirements specified in ISO 8589.7.2 General rulesApply the general guidelines given in ISO 6658 for the execution of these tests. It is particularly important that:a) the assessors taste each without haste (about 30 s interv
37、als);b) the assessors take a sufficient amount of solution to allow exposure to the whole mouth (about 15 ml);c) the assessors rinse the mouth with water (5.1) after evaluating each taste series;d) the samples and water have the same temperature (usually ambient temperature, around 20 C) and that th
38、ey remain at this temperature throughout the tests.8 Identification of tastes8.1 Test solutionsFor each taste, the threshold for the basic tastes and iron sensation shall correspond to a mixture of equal parts of dilutions as mentioned in Table 3.For a trained panel, the recognition of the basic tas
39、tes and metallic sensation shall be at the concentrations listed in Table 3.Table 3 Test solutions for the identification of tastesReference substance Concentrationg/lDilution(see Table 2)aCitric acidCaffeineSodium chlorideSucroseMonosodium glutamateIron(II) sulfate heptahydrate0,280,1951,195,760,29
40、0,003 6D4 + D5D2 + D3D2 + D3D2 + D3D4 + D5D2 + D3aA mixture of 50 % of each dilution in Table 2 of a basic taste.Panellists are presented with one sample of each type and are allowed to familiarize themselves with them in accordance with ISO 8586.Assessors are then presented with a series of the sam
41、e materials (between 9 and 12), repeating certain dilutions and also including one or two vessels containing water. (A sample series could thus comprise, for example, two acid, one water, two salty, two bitter, one water, two umami, two metallic, one sweet.)Prepare as many sample series as there are
42、 assessors.Identify all samples with a random unique three-digit code known only to the test supervisor.Provide each assessor with a jug or bottle of water for rinsing out the mouth. This water shall be identical with that used for the preparation of the dilutions.4 ISO 2012BS ISO 3972:2011 ISO 3972
43、:2011 (E)8.2 DeterminationPresent the vessels containing the test solutions prepared in 8.1 to each of the assessors, and instruct them to proceed as follows.The assessors sample the contents of each vessel, taking a mouthful (about 15 ml) of each, keeping to the order of presentation and without go
44、ing back to previously sampled vessels.After each tasting, the assessors shall enter their assessments on an answer form (see Annex A) or, where applicable, register them using a computerized system.9 Familiarization with the different types of threshold tests9.1 Test solutionsFor each taste, use di
45、lutions D1 to D8 prepared in accordance with Table 2 and divide them among the vessels (6.3).Introduce randomly within each sample series up to three additional vessels containing dilutions of the same concentration as the preceding vessel; this is to eliminate responses given by deduction.The vesse
46、ls shall be coded by means of a random three-digit number.Provide each assessor with a glass and a jug or bottle of water for rinsing the mouth. This water shall be identical to that used for the preparation of the dilutions.9.2 DeterminationIt is recommended that at most three tastes be assessed du
47、ring any one session, in order to avoid sensory fatigue. Meanwhile, it is necessary to repeat the assessment of the tastes during the group sessions.Carry out the test one substance at a time as follows.Present an identified vessel containing water to each assessor advising them to rinse the palate
48、between each sample.Introduce the samples by order of increasing concentration.Do not present all the vessels to the assessors at the same time, as they might be tempted to start with the highest concentration in order to identify easily the taste being tested.Instruct the assessors to sample the co
49、ntents of each vessel in turn, taking a mouthful or about 15 ml of each.Immediately after each tasting, the assessors shall enter on the answer form (see Annex B) the absence of sensation or the taste sensations produced, using the following system of notation:0 No perceived impression? Perceived impression but not identified Perceived taste, , , etc. Identified difference in concentrationInstruct the assessors to add an extra cross each time an increase in concentration is identified, and to write dow
