ASTM E1909-97

Standard Guide for Time-Intensity Evaluation of Sensory Attributes

SCOPE
1.1 This guide covers procedures for conducting and analyzing time intensity (T-I) evaluations of products or other sensory stimuli. Time-intensity is the measurement of the intensity of a single sensory sensation over time in response to a single exposure to a product or other sensory stimulus.

General Information

• Status: Historical
• Publication Date: 09-Sep-1997
• Technical Committee: E18 - Sensory Evaluation
• Drafting Committee: E18.03 - Sensory Theory and Statistics

Relations

• Replaced By: ASTM E1909-97(2003) - Standard Guide for Time-Intensity Evaluation of Sensory Attributes
• Effective Date: 10-Apr-2003

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E 1909 – 97
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Guide for
1
Time-Intensity Evaluation of Sensory Attributes
This standard is issued under the fixed designation E 1909; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This guide covers procedures for conducting and ana-
lyzing time-intensity (T-I) evaluations of products or other
sensory stimuli. Time-intensity is the measurement of the
intensity of a single sensory sensation over time in response to
a single exposure to a product or other sensory stimulus.
1.2 This guide utilizes a specially trained panel to measure
the intensity of a single continuous sensation during the time
from initial exposure:
1.2.1 To its extinction,
1.2.2 To a specified intensity, or
1.2.3 To a predetermined limit of time.
1.3 Applications not covered in this guide include measur-
ing:
1.3.1 Multiple sensations,
1.3.2 Multiple exposures within a single measurement, and
1.3.3 Qualitative or hedonic changes in the perceived sen-
sation.
NOTE 1—Based on a figure from Ref (15).
FIG. 1 Representative Time-Intensity Curve with Selected
1.4 This guide includes protocols for the selection and
Parameters Labeled
training of judges, descriptions and use of physical data
collection devices, and methods of data handling, summariza-
3.1.1 area after I —post-peak area under the curve.
max
tion, and statistical analysis. Illustration of two different data
3.1.2 area before I —pre-peak area under the curve.
max
handling and analysis approaches are included in the appen-
3.1.3 AUC—area under the curve.
dixes.
3.1.4 I or peak intensity—maximum observed intensity
max
1.5 This guide is not applicable to measure product shelf life
during the time of measurement.
or stability that require evaluations at discrete time intervals.
3.1.5 perimeter—measured distance of perimeter of area
1.6 This standard does not purport to address all of the
delineated by T-I curve.
safety concerns, if any, associated with its use. It is the
3.1.6 plateau time—duration of peak intensity.
responsibility of the user of this standard to establish appro-
3.1.7 rate of increase—rate of intensity increase before
priate safety and health practices and determine the applica-
peak intensity (slope).
bility of regulatory limitations prior to use.
3.1.8 rate of decrease—rate of intensity decrease after peak
intensity (slope).
2. Referenced Documents
3.1.9 T or duration time—time from onset of sensation
dur
2.1 ASTM Standards:
until it can no longer be perceived (T –T ).
ext onset
E 253 Terminology of Sensory Evaluation of Materials and
2 3.1.10 T or time to extinction—time from initial exposure
ext
Products
to the stimulus (T ) until it can no longer be perceived.
init
3. Terminology 3.1.11 T —time of initial exposure to the stimulus, typi-
init
cally when the clock starts.
3.1 Definitions of Terms Specific to This Standard: See Fig.
3.1.12 T —time to reach maximum intensity of the sen-
max
1.
sation after exposure to the stimulus.
3.1.13 T —time point when the stimulus is first per-
onset
1
This guide is under the jurisdiction of ASTM Committee E-18 on Sensory
ceived after initial exposure to the stimulus.
Evaluation of Materials and Products and is the direct responsibility of Subcom-
3.1.14 T or truncated time—time until a specified mini-
trun
mittee E18.03 on Sensory Theory and Statistics.
mum intensity or until a pre-determined time point has been
Current edition approved Sept. 10, 1997. Published August 1998.
2
Annual Book of ASTM Standards, Vol 15.07. reached.
1

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NOTICE:¬This¬standard¬has¬either¬been¬superceded¬and¬replaced¬by¬a¬new¬version¬or¬discontinued.¬
Contact¬ASTM¬International¬(www.astm.org)¬for¬the¬latest¬information.¬
E 1909
3.2 The graphical illustration of a typical time-intensity 6.1.2.3 Accurately record changes in sensations as they
curve is shown in Fig. 1. The time increment may be seconds, occur,
minutes, hours, etc., depending upon the characteristic of the
6.1.2.4 Perform consistently,
particular material under study.
6.1.2.5 Perform all test procedures with appropriate motor
skills (for example, ability to chew gum while manipulating the
4. Summary of Guide
input device to indicate the intensity of the mint flavor).
4.1 This guide describes procedures utilizing specially
6.1.3 Compared to other descriptive methods, T-I panelists
trained panelists to measure the intensity of a single sensory
requ
...