iTeh StandardsiTeh Standards
EURUSD
Your shopping cart is empty.
ASTM

ASTM E2262-03

(Practice)

Standard Practice for Estimating Thurstonian Discriminal Distances

Standard Practice for Estimating Thurstonian Discriminal Distances

SCOPE
1.1 This practice describes procedures to estimate Thurstonian discriminal distances (that is, d' values) from data obtained on two samples. Procedures are presented for four forced-choice methods (that is, the triangle, the duo-trio, the 3-alternative-forced-choice (or 3-AFC) and the 2-AFC (also called the directional difference test)), the A/Not-A method, the Same-Different method and for data obtained from ordered category scales. Procedures for estimating the variance of  d' are also presented. Thus, confidence intervals and statistical tests can be calculated for d'.
1.2 The procedures in this document pertain only to the unidimensional, equal-variance model. Other, more complicated Thurstonian models, involving multiple dimensions and unequal variances exist but are not addressed in this standard. The procedure for forced-choice methods is limited to dichotomous responses. The procedure for the A/Not-A method assumes equal sample sizes for the two samples. The procedure for the Same-Different method assumes equal sample sizes for the matched and unmatched pairs of samples. For all methods, only unreplicated tests are considered. (Tests in which each assessor performs multiple (that is, replicated) evaluations require different analyses.)
1.3 Thurstonian scaling is a method for measuring the perceptual difference between two samples based on a probabilistic model for categorical choice decision making. The magnitude of the perceived difference, δ, can be estimated from the assessors' categorical choices using the methods described in this practice (See Appendix X3 for a more detailed description of Thurstonian scaling).
1.4 In theory, the Thurstonian does not depend on the method used to measure the difference between two samples. As such, δ provides a common scale of measure for comparing samples measured under a variety of test conditions. For example, Thurstonian scaling can be used to compare products measured under different test conditions, to compare panels (trained, consumer or both) that have evaluated the same samples (using the same or different test methods) and to compare test methods on their ability to discriminate samples that exhibit a fixed sensory difference.
1.5 This standard may involve hazardous materials, operations and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

Status
Historical
Publication Date
09-Jul-2003
ICS
67.240 - Sensory analysis
Technical Committee
E18 - Sensory Evaluation
Drafting Committee
E18.03 - Sensory Theory and Statistics
Current Stage
Ref Project

Relations

Replaced By
ASTM E2262-03(2009) - Standard Practice for Estimating Thurstonian Discriminal Distances
Effective Date
01-Sep-2009
Referred By
ASTM E1885-18 - Standard Test Method for Sensory Analysis—Triangle Test
Effective Date
10-Jul-2003
Referred By
ASTM E3009-23 - Standard Test Method for Sensory Analysis—Tetrad Test
Effective Date
10-Jul-2003
Referred By
ASTM E2610-18 - Standard Test Method for Sensory Analysis—Duo-Trio Test
Effective Date
10-Jul-2003

Buy Standard

ASTM E2262-03 - Standard Practice for Estimating Thurstonian Discriminal DistancesASTM E2262-03 - Standard Practice for Estimating Thurstonian Discriminal Distances
PreviousNext
Standard
ASTM E2262-03 - Standard Practice for Estimating Thurstonian Discriminal Distances
English language
47 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:E2262–03
Standard Practice for
1
Estimating Thurstonian Discriminal Distances
This standard is issued under the fixed designation E2262; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope compare test methods on their ability to discriminate samples
that exhibit a fixed sensory difference.
1.1 This practice describes procedures to estimate Thursto-
1.5 This standard may involve hazardous materials, opera-
nian discriminal distances (that is, d’ values) from data
tions and equipment. This standard does not purport to address
obtained on two samples. Procedures are presented for four
all of the safety concerns, if any, associated with its use. It is
forced-choice methods (that is, the triangle, the duo-trio, the
the responsibility of the user of this standard to establish
3-alternative-forced-choice (or 3-AFC) and the 2-AFC (also
appropriate safety and health practices and determine the
calledthedirectionaldifferencetest)),theA/Not-Amethod,the
applicability of regulatory limitations prior to use.
Same-Different method and for data obtained from ordered
category scales. Procedures for estimating the variance of d’
2. Referenced Documents
are also presented. Thus, confidence intervals and statistical
2
2.1 ASTM Standards:
tests can be calculated for d’.
E253 Terminology Relating to Sensory Evaluation of Ma-
1.2 The procedures in this document pertain only to the
terials and Products
unidimensional, equal-variance model. Other, more compli-
E456 Terminology Relating to Quality and Statistics
cated Thurstonian models, involving multiple dimensions and
E460 PracticeforDeterminingEffectofPackagingonFood
unequal variances exist but are not addressed in this standard.
and Beverage Products During Storage
Theprocedureforforced-choicemethodsislimitedtodichoto-
E679 Practice for Determination of Odor andTasteThresh-
mous responses. The procedure for the A/Not-A method
olds By a Forced-Choice Ascending Concentration Series
assumesequalsamplesizesforthetwosamples.Theprocedure
Method of Limits
for the Same-Different method assumes equal sample sizes for
E1432 Practice for Defining and Calculating Individual and
the matched and unmatched pairs of samples. For all methods,
Group Sensory Thresholds from Forced-Choice Data Sets
only unreplicated tests are considered. (Tests in which each
of Intermediate Size
assessor performs multiple (that is, replicated) evaluations
E1593 Guide for Assessing the Efficacy of Air Care Prod-
require different analyses.)
ucts in Reducing Sensorly Perceived Indoor Air Malodor
1.3 Thurstonian scaling is a method for measuring the
Intensity
perceptual difference between two samples based on a proba-
E1627 Practice for Sensory Evaluation of Edible Oils and
bilistic model for categorical choice decision making. The
Fats
magnitude of the perceived difference, d, can be estimated
E1697 Test Method for Unipolar Magnitude Estimation of
from the assessors’ categorical choices using the methods
Sensory Attributes
describedinthispractice(SeeAppendixX3foramoredetailed
E1810 Practice for Evaluating Effects of Contaminants on
description of Thurstonian scaling).
Odor and Taste of Exposed Fish
1.4 In theory, the Thurstonian d does not depend on the
E1879 GuideforSensoryEvaluationofBeveragesContain-
method used to measure the difference between two samples.
ing Alcohol
Assuch, dprovidesacommonscaleofmeasureforcomparing
E1885 Test Method for Sensory Analysis—Triangle Test
samples measured under a variety of test conditions. For
E1958 Guide for Sensory Claim Substantiation
example,Thurstonian scaling can be used to compare products
E2049 Guide for Quantitative Attribute Evaluation of
measured under different test conditions, to compare panels
Fragrance/Odors for Shampoos and Hair Conditioners by
(trained, consumer or both) that have evaluated the same
Trained Assessors
samples (using the same or different test methods) and to
E2164 Test Method for Directional Difference Test
2
2.2 ASTM Publication:
1
This practice is under the jurisdiction of ASTM Committee E18 on Sensory
2
Evaluation of Materials and Products and is the direct responsibility of Subcom- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
mittee E18.03 on Sensory Theory and Statistics. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved July 10, 2003. Published Aug. 2003. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
E2262-03. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, We
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.

This May Also Interest You

ASTM
ASTM E3313-23a(Guide)
Standard Guide for Communication of Assessor and Panel Performance

SIGNIFICANCE AND USE
4.1 The procedures recommended in this guide can be used by a panel leader to provide assessors and panels feedback: (1) on their data-based performance, (2) on any behavior changes that are needed to improve their performance, and (3) to motivate assessors to remain engaged with the panel tasks. The aim of all these types of feedback is to ensure the generation of repeatable and valid data.  
4.2 This guide provides direction for how to achieve mutually beneficial feedback exchanges between assessors and panel leaders.
SCOPE
1.1 This guide provides guidance to sensory panel leaders on how to deliver performance feedback to trained sensory assessors and panels. This guide is not intended to be used by individual assessors or anyone unfamiliar with the panel.  
1.2 This guide covers recommended feedback given throughout assessor training, panel development, and ongoing assessor and panel monitoring.  
1.3 This guide examines aspects of feedback including: types, when to provide, effective delivery, and alignment to performance expectations for assessors.  
1.4 Descriptive, discrimination, and quality panels are within the scope of this guide.  
1.5 This guide does not cover consumer panels (qualitative or quantitative).  
1.6 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.  
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Guide
    18 pages
    English language
    sale 15% off
  • Guide
    18 pages
    English language
    sale 15% off
ASTM
ASTM E253-23a(Terminology)
Standard Terminology Relating to Sensory Evaluation of Materials and Products
  • Standard
    8 pages
    English language
    sale 15% off
  • Standard
    8 pages
    English language
    sale 15% off
ASTM
ASTM E1346-16(2023)(Practice)
Standard Practice for Bulk Sampling, Handling, and Preparing Edible Vegetable Oils for Sensory Evaluation

SIGNIFICANCE AND USE
4.1 This practice is designed for use by the oil processor or research laboratory for evaluation by a trained sensory panel, or for use by quality control (QC) and quality assurance (QA) personnel for sampling from a tank truck, car, or any other bulk transportation container, or by both.  
4.2 The consistent use of this practice will provide representative samples for all sensory, chemical and physical analyses and will protect the oil from oxidation.  
4.3 The objective of this practice is to ensure that the sample is representative of the sample source from the time of sampling until the time of evaluation and to protect oil quality during that time.  
4.4 This practice addresses neither evaluation and scaling techniques, nor the sampling, handling, and preparing of solid fats.
SCOPE
1.1 This practice covers the recommended procedures for bulk sampling, handling, and preparing edible vegetable oil (liquid at room temperature) prior to sensory evaluation.  
1.2 This practice is consistent with the background information presented in ASTM STP 433, ASTM Manual 26, and ASTM STP 758. These should be consulted for supplemental guidance.  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    4 pages
    English language
    sale 15% off
ASTM
ASTM E1958-22(Guide)
Standard Guide for Sensory Claim Substantiation

SCOPE
1.1 This guide covers reasonable practices for designing and implementing sensory tests that validate claims pertaining only to the sensory or perceptual attributes, or both, of a product. This guide was developed for use in the United States and must be adapted to the laws and regulations for advertisement claim substantiation for any other country. A claim is a statement about a product that highlights its advantages, sensory or perceptual attributes, or product changes or differences compared to other products in order to enhance its marketability. Attribute, performance, and hedonic claims, both comparative and non-comparative, are covered. This guide includes broad principles covering selecting and recruiting representative consumer samples, selecting and preparing products, constructing product rating forms, test execution, and statistical handling of data. The objective of this guide is to disseminate good sensory and consumer testing practices. Validation of claims should be made more defendable if the essence of this guide is followed.    
Table of Contents    
Introduction  
Scope  
1  
Referenced Documents  
2  
Terminology  
3  
Basis of Claim Classification  
4  
Consumer Based Affective Testing  
5  
Sampling  
5.1  
Sampling Techniques  
5.2  
Selection of Products  
5.3  
Sampling of Products When Both Products Are Currently on
the Market  
5.4  
Handling of Products When Both Products Are Currently on
the Market  
5.5  
Sampling of Products Not Yet on the Market  
5.6  
Sample Preparation/Test Protocol  
5.7  
Test Design—Consumer Testing  
6  
Data Collection Strategies  
6.6  
Interviewing Techniques  
6.7  
Type of Questions  
6.8  
Questionnaire Design  
6.9  
Instruction to Respondents  
6.10  
Instructions to Interviewers  
6.11  
General/Overall Questions  
6.12  
Positioning of the Key Product Rating Questions  
6.13  
Total Test Context and Presentation Matters  
6.14  
Specific Attribute Questions  
6.15  
Classification or Demographic Questions  
6.16  
Preference Questions  
6.17  
Test Location  
7  
Test Execution by Way of Test Agencies—Food and Non-food
Testing  
8  
Documents to Retain in Sensory Claims Substantiation Research  
9  
Laboratory Testing Methods  
10  
Types of Tests  
10.2  
Advantages and Limitations of the Use of Trained Descriptive
Panels in Claims Support Research  
10.3  
Test Design—Laboratory Testing  
11  
Product Procurement  
11.6  
Experimental Design  
11.7  
Data Collection  
11.8  
Data Analysis  
11.9  
Questionnaire Construction  
12  
Test Facility  
13  
Statistical Analysis  
14  
Paired-Preference Studies  
14.1  
Superiority Claims  
14.2  
Equivalence Claims  
14.3  
Unsurpassed Claims  
14.4  
Paired Comparison/Difference Studies  
14.5  
Analysis of Data from Scales  
14.6  
Keywords  
15  
Commonly Asked Questions About ASTM and Claim
Substantiation  
Appendix X1  
1.2 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Guide
    32 pages
    English language
    sale 15% off
  • Guide
    32 pages
    English language
    sale 15% off
ASTM
ASTM E2299-13(2021)(Guide)
Standard Guide for Sensory Evaluation of Products by Children and Minors

SIGNIFICANCE AND USE
4.1 It is necessary and useful to test with children because they represent the real end-users for many products. Some products are developed specifically for children, and some are dual-purpose products that are intended for adults and children. Examples include: baby foods, diapers, ready-to-eat cereal, juices, food or lunch kits, candy, toys, vitamins and other pharmaceuticals, music and videos, interactive learning tools, and packaging.  
4.2 Children have influence over adults' purchase decisions and are responsible for many or some of their own purchase decisions.  
4.3 Creating a product for children requires input from children because their wants and needs differ from those of adults. For example, they may differ from adults in preferences or sensory acuity, or both, for sweetness, saltiness, carbonation, and texture. It is impossible to predict the nature of these differences without actual input from the intended target audience.
SCOPE
1.1 This guide provides a framework for understanding the issues relating to conducting sensory and market research studies with children. It recommends and provides examples for developing ethical, safe, and valid testing methods. It focuses specifically on the concerns relevant to testing with children from birth through preadolescence. The guide assumes that minors older than 15 years of age are generally capable of performing sensory tests like adults, and therefore, all standard procedures used with adult subjects apply. The one exception, however, is legal consent where parental/legal guardian permission should be obtained for anyone under 18 years of age.  
1.2 This guide will take into account the wide range of children's physical, emotional, and cognitive levels of development. It will prove useful for developing tasks that are understandable to children. It recommends alternative modes for children to communicate their opinions or perceptions back to the researcher, such as appropriate scales and measures.  
1.3 The ethical standard presented in this document should be viewed as a minimum requirement for testing with minors. The safety and protection of children as respondents, as well as an attitude of respect for the value of their input should be of primary concern to the researcher.  
1.4 The considerations raised in this document may also be useful when testing with the elderly or with adults who have developmental handicaps.  
1.5 This document is not intended to be a complete description of reliable sensory testing techniques and methodologies. It focuses instead on special considerations for the specific application of sensory techniques when testing with children. It assumes knowledge of basic sensory and statistical analysis techniques.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Guide
    14 pages
    English language
    sale 15% off
ASTM
ASTM E2262-03(2020)(Practice)
Standard Practice for Estimating Thurstonian Discriminal Distances

SIGNIFICANCE AND USE
5.1 Under the assumptions of the model, the Thurstonian model approach to measuring the perceived difference between two samples (whether overall or for a specific attribute) is independent of the sensory method used to collect the data. Converting results obtained from different test methods to d' values permits the assessment of relative differences among samples without requiring that the samples be compared to each other directly or that the same test methods be used for all pairs of samples.  
5.2 Thurstonian scaling has been applied to:  
5.2.1 Creating a historical database to track differences between production and reference samples over periods in which different test methods were used to measure the difference,  
5.2.2 Comparing the relative sensitivities of different user groups and consumer segments,  
5.2.3 Comparing trained panels that use different measuring techniques,  
5.2.4 Comparing the relative sensitivities of consumers versus trained panels,  
5.2.5 Comparing different methods of consumer testing (for example, CLT versus HUT, preference versus hedonic scales, etc.), and  
5.2.6 Comparing different discrimination test methods.
SCOPE
1.1 This practice describes procedures to estimate Thurstonian discriminal distances (that is, d' values) from data obtained on two samples. Procedures are presented for four forced-choice methods (that is, the triangle, the Duo-Trio, the 3-alternative-forced-choice (or 3-AFC) and the 2-AFC (also called the directional difference test)), the A/Not-A method, the Same-Different method, and for data obtained from ordered category scales. Procedures for estimating the variance of d' are also presented. Thus, confidence intervals and statistical tests can be calculated for d'.  
1.2 The procedures in this practice pertain only to the unidimensional, equal-variance model. Other, more complicated Thurstonian models, involving multiple dimensions and unequal variances exist but are not addressed in this practice. The procedure for forced-choice methods is limited to dichotomous responses. The procedure for the A/Not-A method assumes equal sample sizes for the two samples. The procedure for the Same-Different method assumes equal sample sizes for the matched and unmatched pairs of samples. For all methods, only unreplicated tests are considered. (Tests in which each assessor performs multiple (that is, replicated) evaluations require different analyses.)  
1.3 Thurstonian scaling is a method for measuring the perceptual difference between two samples based on a probabilistic model for categorical choice decision making. The magnitude of the perceived difference, δ, can be estimated from the assessors' categorical choices using the methods described in this practice. (See Appendix X3 for a more detailed description of Thurstonian scaling.)  
1.4 In theory, the Thurstonian δ does not depend on the method used to measure the difference between two samples. As such, δ provides a common scale of measure for comparing samples measured under a variety of test conditions. For example, Thurstonian scaling can be used to compare products measured under different test conditions, to compare panels (trained, consumer or both) that have evaluated the same samples (using the same or different test methods) and to compare test methods on their ability to discriminate samples that exhibit a fixed sensory difference.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations is...

  • Standard
    46 pages
    English language
    sale 15% off
ASTM
ASTM E1697-05(2020)(Test Method)
Standard Test Method for Unipolar Magnitude Estimation of Sensory Attributes

SIGNIFICANCE AND USE
5.1 Magnitude estimation may be used to measure and compare the intensities of attributes of a wide variety of products.  
5.2 Magnitude estimation provides a large degree of flexibility for both the experimenter and the assessor. Once trained in magnitude estimation, assessors are generally able to apply their skill to a wide variety of sample types and attributes, with minimal additional training.  
5.3 Magnitude estimation is not as susceptible to end-effects as interval scaling techniques. These can occur when assessors are not familiar with the entire range of sensations being presented. Under these circumstances, assessors may assign an early sample to a category which is too close to one end of the scale. Subsequently, they may “run out of scale” and be forced to assign perceptually different samples to the same category. This should not occur with magnitude estimation, as, in theory, there are an infinite number of categories.  
5.4 Magnitude estimation is one frequently used technique that permits the representation of data in terms of Stevens' Power Law.  
5.5 The disadvantages of magnitude estimation arise primarily from the requirements of the data analysis.  
5.5.1 Permitting each assessor to choose a different numerical scale may produce significant assessor effects. This disadvantage can be overcome in a number of ways, as follows. The experimenter must choose the approach most appropriate for the circumstances.
5.5.1.1 Experiments can be designed such that analysis of variance can be used to remove the assessor effects and interactions.
5.5.1.2 Alternatively, assessors can be forced to a common scale, either by training or by use of external reference samples with assigned values (modulus).
5.5.1.3 Finally, each assessor's data can be brought to a common scale by one of a variety of normalizing methods.  
5.5.2 Logarithms must be applied before carrying out data analysis. This becomes problematic if values are near threshold, as a logarit...
SCOPE
1.1 This test method describes a procedure for the application of unipolar magnitude estimation to the evaluation of the magnitude of sensory attributes. The test method covers procedures for the training of assessors to produce magnitude estimations and statistical evaluation of the estimations.  
1.2 Magnitude estimation is a psychophysical scaling technique in which assessors assign numeric values to the magnitude of an attribute. The only constraint placed upon the assessor is that the values assigned should conform to a ratio principle. For example, if the attribute seems twice as strong in sample B when compared to sample A, sample B should receive a value which is twice the value assigned to sample A.  
1.3 The intensity of attributes such as pleasantness, sweetness, saltiness or softness can be evaluated using magnitude estimation.  
1.4 Magnitude estimation may provide advantages over other scaling methods, particularly when the number of assessors and the time available for training are limited. With approximately 1 h of training, a panel of 15 to 20 naive individuals can produce data of adequate precision and reproducibility. Any additional training that may be required to ensure that the assessors can properly identify the attribute being evaluated is beyond the scope of this test method.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    9 pages
    English language
    sale 15% off
ASTM
ASTM E679-19(Practice)
Standard Practice for Determination of Odor and Taste Thresholds By a Forced-Choice Ascending Concentration Series Method of Limits

SIGNIFICANCE AND USE
5.1 Sensory thresholds are used to determine the potential of substances at low concentrations to impart odor, taste, skinfeel, etc. to some form of matter.  
5.2 Thresholds are used, for example, in setting limits for air pollution, in noise abatement, in water treatment, and in food systems.  
5.3 Thresholds are used to characterize and compare the sensitivity of individual or groups to given stimuli, for example, in medicine, in ethnic studies, and in the study of animal species.
SCOPE
1.1 This practice describes a rapid test for determining sensory thresholds of any substance in any medium.  
1.2 It prescribes an overall design of sample preparation and a procedure for calculating the results.  
1.3 The threshold may be characterized as being either (a) only detection  (awareness) that a very small amount of added substance is present but not necessarily recognizable, or (b) recognition  of the nature of the added substance.  
1.4 The medium may be a gas, such as air, a liquid, such as water or some beverage, or a solid form of matter. The medium may be odorless or tasteless, or may exhibit a characteristic odor or taste per se.  
1.5 This practice describes the use of a multiple forced-choice sample presentation method in an ascending concentration series, similar to the method of limits.  
1.6 Physical methods of sample presentation for threshold determination are not a part of this practice, and will depend on the physical state, size, shape, availability, and other properties of the samples.  
1.7 It is recognized that the degree of training received by a panel of assessors with a particular substance may have a profound influence on the threshold obtained with that substance  (1).2  
1.8 Thresholds determined by using one physical method of presentation are not necessarily equivalent to values obtained by another method.  
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    7 pages
    English language
    sale 15% off
  • Standard
    7 pages
    English language
    sale 15% off
ASTM
ASTM E1627-19(Practice)
Standard Practice for Sensory Evaluation of Edible Oils and Fats

SIGNIFICANCE AND USE
5.1 The application of this practice will help ensure consistency in procedures used for the sensory evaluation of edible oils and fats.
SCOPE
1.1 This practice covers the recommended procedures for the sensory evaluation of edible oils and fats.  
1.2 This practice covers techniques for evaluating appearance, odor, and flavor in fats and oils, for determining overall odor and flavor intensity, and the intensity of individual odors or flavors.  
1.3 The techniques used in this practice are applicable to oils (liquid at room temperature) and liquified fats (solid at room temperature).  
1.4 The values in SI units are to be regarded as the standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    5 pages
    English language
    sale 15% off
  • Standard
    5 pages
    English language
    sale 15% off
ASTM
ASTM E1885-18(Test Method)
Standard Test Method for Sensory Analysis—Triangle Test

SIGNIFICANCE AND USE
5.1 This test method is effective for the following test objectives:  
5.1.1 To determine whether a perceivable difference results or a perceivable difference does not result, for example, when a change is made in ingredients, processing, packaging, handling or storage; or  
5.1.2 To select, train and monitor assessors.  
5.2 This test method itself does not change whether the purpose of the triangle test is to determine that two products are perceivably different versus that the products are not perceivably different. Only the selected values of pd, α, and β change. If the objective of the test is to determine if there is a perceivable difference between two products, then the value selected for α is typically smaller than the value selected for β. If the objective is to determine if the two products are sufficiently similar to be used interchangeably, then the value selected for β is typically smaller than the value selected for α and the value of pd is selected to define “sufficiently similar.”
SCOPE
1.1 This test method covers a procedure for determining whether a perceptible sensory difference exists between samples of two products.  
1.2 This test method applies whether a difference may exist in a single sensory attribute or in several.  
1.3 This test method is applicable when the nature of the difference between the samples is unknown. It does not determine the size or the direction of the difference. The attribute(s) responsible for the difference are not identified.  
1.4 Compared to the duo-trio test, the triangle test can achieve an equivalent level of statistical significance with fewer assessors. For details on how the triangle test compares to other three-sample tests, see Refs (1) , (2), (3) and (4).2  
1.5 This test method is applicable only if the products are homogeneous. If two samples of the same product can often be distinguished, then another method, for example, descriptive analysis, may be more appropriate.  
1.6 This test method is applicable only when the products do not cause excessive sensory fatigue, carryover or adaptation.  
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

  • Standard
    9 pages
    English language
    sale 15% off
  • Standard
    9 pages
    English language
    sale 15% off