ASTM E2454-05(2011)
(Guide)Standard Guide for Sensory Evaluation Methods to Determine the Sensory Shelf Life of Consumer Products
Standard Guide for Sensory Evaluation Methods to Determine the Sensory Shelf Life of Consumer Products
SIGNIFICANCE AND USE
Measuring product changes over time serves as a practical basis for establishing the shelf life of a product. This information can also be used to assess the effects of new technology, processing, ingredients, packaging, and so forth, on the product’s shelf life.
This guide provides a summary of the criteria to be considered and appropriate test methods for determining a product’s sensory shelf life.
Previous sensory research with similar products, marketing research, product technology, manufacturing considerations, marketing objectives, and other business criteria can all play a part in determining sensory end point criteria.
The decision risk, end-point determination criteria, and shelf life procedure should be reviewed and agreed to by those involved with the project, that is: R&D, Marketing, Sales, Manufacturing, Quality Assurance, Quality Control, Sensory Evaluation, and so forth.
SCOPE
1.1 This guide provides appropriate sensory testing approaches and possible decision criteria for establishing sensory shelf life of consumer products. It describes research considerations including: product selection and handling, appropriate application of various sensory test methods, selection of test intervals, and data analysis techniques for the determination of a product’s shelf life end-point. As such, this document covers shelf life studies designed to identify the sensory end-point of a product’s life to manage business risk and meet business needs. This guide will focus on the practical considerations and approaches, risks, and criteria that must be considered in designing, executing, and interpreting shelf life results.
1.2 Sensory shelf life is the time period during which the products’ sensory characteristics and performance are as intended by the manufacturer. The product is consumable or usable during this period, providing the end-user with the intended sensory characteristics, performance, and benefits. After this period, however, the product has characteristics or attributes that are not as intended, or it does not perform the same functions as fresh products or those selected before the end of shelf life.
1.3 The goal of all shelf life determination is to estimate the time at which a consumer product is no longer usable, unfit for consumption, or no longer has the intended sensory characteristics. The determination of a sensory end-point is a function of the criteria selected, the test method used, and sampling risk. The three following test methods are most commonly used: (1) discrimination, (2) descriptive, and (3) affective. Researchers have to select criteria and methods that best suit the business risks associated with the selection of a final shelf life end point.
1.4 Research techniques designed to identify the causes of sensory shelf life changes or to develop predictive models of shelf life are beyond the scope of this document. These include the application of regression analysis to develop statistical models designed to predict sensory shelf life, studies that assess the impact of various storage conditions, packaging materials, or product formulations on the shelf life of products, and studies designed to identify the causes of changes in product attributes over time. However, many of the research methods, experimental design considerations, and data analysis techniques discussed in this document can be applied to these other types of shelf life-related research.
1.5 This guide is not intended to provide a detailed description of how to conduct reliable sensory testing. It assumes knowledge of basic sensory and statistical analysis techniques, focusing instead on special considerations for the specific application of sensory testing method to shelf life determination.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: E2454 − 05 (Reapproved 2011)
Standard Guide for
Sensory Evaluation Methods to Determine the Sensory
Shelf Life of Consumer Products
This standard is issued under the fixed designation E2454; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope models designed to predict sensory shelf life, studies that
assess the impact of various storage conditions, packaging
1.1 This guide provides appropriate sensory testing ap-
materials, or product formulations on the shelf life of products,
proaches and possible decision criteria for establishing sensory
and studies designed to identify the causes of changes in
shelf life of consumer products. It describes research consid-
product attributes over time. However, many of the research
erations including: product selection and handling, appropriate
methods,experimentaldesignconsiderations,anddataanalysis
application of various sensory test methods, selection of test
techniques discussed in this document can be applied to these
intervals, and data analysis techniques for the determination of
other types of shelf life-related research.
a product’s shelf life end-point.As such, this document covers
shelf life studies designed to identify the sensory end-point of 1.5 This guide is not intended to provide a detailed descrip-
a product’s life to manage business risk and meet business tion of how to conduct reliable sensory testing. It assumes
needs.Thisguidewillfocusonthepracticalconsiderationsand knowledge of basic sensory and statistical analysis techniques,
approaches, risks, and criteria that must be considered in focusing instead on special considerations for the specific
designing, executing, and interpreting shelf life results. application of sensory testing method to shelf life determina-
tion.
1.2 Sensory shelf life is the time period during which the
products’ sensory characteristics and performance are as in-
2. Referenced Documents
tended by the manufacturer. The product is consumable or
2.1 ASTM Standards:
usable during this period, providing the end-user with the
E253 Terminology Relating to Sensory Evaluation of Mate-
intended sensory characteristics, performance, and benefits.
rials and Products
After this period, however, the product has characteristics or
attributes that are not as intended, or it does not perform the 2.2 ASTM Manuals:
same functions as fresh products or those selected before the
MNL 13 Descriptive Analysis Testing
end of shelf life. MNL 26 Sensory Testing Methods
MNL 30 Relating Consumer, Descriptive, and Laboratory
1.3 The goal of all shelf life determination is to estimate the
Data to Better Understand Consumer Responses
time at which a consumer product is no longer usable, unfit for
consumption, or no longer has the intended sensory character-
3. Terminology
istics.Thedeterminationofasensoryend-pointisafunctionof
3.1 Definitions of Terms Specific to This Standard:
the criteria selected, the test method used, and sampling risk.
3.1.1 accelerated storage/aging—subjecting a product to
The three following test methods are most commonly used: (1)
extreme or stressed conditions, such as elevated temperatures
discrimination, (2) descriptive, and (3) affective. Researchers
or humidity, to create changes in product characteristics that
have to select criteria and methods that best suit the business
are assumed to be related to aging the product.
risksassociatedwiththeselectionofafinalshelflifeendpoint.
3.1.2 control parameters for sensory shelf life determination
1.4 Research techniques designed to identify the causes of
(known as “control”)—specific product or data set (based on
sensory shelf life changes or to develop predictive models of
previous sensory research) designated as the one to which the
shelf life are beyond the scope of this document.These include
data from stored products are to be compared (see Section 6).
the application of regression analysis to develop statistical
1 2
This guide is under the jurisdiction of ASTM Committee E18 on Sensory For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Evaluation and is the direct responsibility of Subcommittee E18.05 on Sensory contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Applications--General. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Aug. 1, 2011. Published August 2011. Originally the ASTM website.
approved in 2005. Last previous edition approved in 2005 as E2454–05. DOI: Available fromASTM International Headquarters, 100 Barr Harbor Drive, PO
10.1520/E2454-05R11. Box C700, West Conshohocken, PA 19428–2959.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2454 − 05 (2011)
3.1.3 controlled conditions—set of environmental param- 4.4 Select Criteria to Determine the End-Point—Products
eters (temperature, humidity, light, oxygen, and so forth) that do change over time. End-point criteria can be one of the
are maintained and monitored so that changes in product following sensory analytical or consumer criteria, or both:
attributes can be evaluated relative to these parameters. For 4.4.1 The product’s overall sensory profile has changed.
example, controlled ambient refers to maintaining a tempera- 4.4.2 A product’s attribute(s) (including off-notes) that is
ture of 21 to 24°C in storing the product. (are) known or suspected to be key to the consumers’ percep-
tion of the product has changed.
3.1.4 end point—point at which a product no longer meets
4.4.3 Consumers consider the product no longer acceptable.
predetermined criteria as defined by test data (for example,
discrimination, descriptive, or affective, or a combination
NOTE 1—Selection of end-point criteria depends on the extent to which
thereof). the sensory attributes of the target product are required to remain
unvarying and the extent to which maintaining consumer acceptance is
3.1.5 pull out date(s)—predetermined point(s) in time at
deemed critical to the business.
which the product is removed from storage for evaluation.
4.5 Select Sensory Test Method—Discrimination,
3.1.6 sensory characteristics—anyattributesoftheproducts
descriptive, or affective methods can be used to determine the
that are assessed using the sensory methods that measure the
shelf life of a product. Selection of the method depends on
human response to that product.
chosen end-point criteria. For example, affective testing is
3.1.7 shelf life—time period that a product may be stored
required if a given consumer acceptance is the chosen end-
before reaching its end point.
point criterion.
3.1.8 shelflifetesting—method(s)todeterminetheeffectsof
4.6 Define Representative Assessors—If discrimination or
aging or storage conditions, or both, on product(s) character-
descriptive test methods are selected, the assessors used are
istics for purposes of determining a product’s shelf life. This
typically trained panelists. If consumer test methods are
testing is designed to manage distribution system risk.
selected, then a sample of consumers must be drawn to
3.1.9 uncontrolled ambient—also known as room
represent the population of potential consumers.
temperature, uncontrolled conditions (that is, temperature of
4.7 Select Representative Products—Products selected for
storage location or environmental factors, or both) which
shelf life testing must be from representative production
fluctuate with changes in weather, time of day, location, and so
batches and production dates and appropriately processed and
forth (see 3.1.3).
packaged. In some situations, products should be subjected to
3.1.10 zero time point—time when the shelf life testing
typical distribution conditions (that is, vibration, temperature
begins. It can be when the product is manufactured, when the
elevation/reduction, temperature cycling, and so forth). If
ingredients equilibrate, when the product is put into storage
testing an experimental product (for example, changes in
conditions, or when the consumer is first likely to see it.
ingredients, formulation, processing, or packaging), samples
should be representative of production batches of the experi-
4. Summary of Guide
mental product. The amount of product required from each
production batch is dependent on the estimated length of
4.1 This guide is intended to cover the basic issues and
storage, number of storage conditions, methods of evaluation,
practicalrequirementsofconductingashelflifestudydesigned
and frequency of testing.
to identify end points in a product’s shelf life.
4.8 Determine the End-Point—The end-point is selected
4.2 Define Research Objective—The purpose of a shelf life
based on the chosen end-point criteria, the type of product
project should be clearly stated before the study is imple-
tested,thetestmethodselected,previousknowledgeofproduct
mented. Common objectives are as follows: “determine the
changes over time, and the company’s business needs.
amount of elapsed time a product remains acceptable to
consumers,” or “determine specific use-by dates,” or “under-
5. Significance and Use
stand the amount of time elapsed before a sensory defect is
detectable.”
5.1 Measuring product changes over time serves as a
practical basis for establishing the shelf life of a product. This
4.3 Identify Decision Risk—Decision risk is defined as the
information can also be used to assess the effects of new
balance of positive and negative outcomes associated with the
technology, processing, ingredients, packaging, and so forth,
selection of a specific end-point. Positive outcomes can be
on the product’s shelf life.
defined as correctly estimating the time a product remains
within its intended sensory criteria. Negative outcomes can be
5.2 This guide provides a summary of the criteria to be
defined as leaving a product on the shelf after it is acceptable,
considered and appropriate test methods for determining a
thus increasing the chances that end-users will be dissatisfied
product’s sensory shelf life.
and no longer purchase the product in the future.Another type
5.3 Previous sensory research with similar products, mar-
of negative outcome is to identify a too-early end-point, thus
keting research, product technology, manufacturing
requiring shelf removal of product that is still usable to the
considerations, marketing objectives, and other business crite-
consumer. Before the researcher embarks on a shelf life study,
ria can all play a part in determining sensory end point criteria.
the risk to the consumer franchise must be balanced with the
use of testing resources, as a properly designed shelf life study 5.4 The decision risk, end-point determination criteria, and
can use a lot of resources. shelf life procedure should be reviewed and agreed to by those
E2454 − 05 (2011)
involved with the project, that is: R&D, Marketing, Sales, control products are in fact not different in either overall
Manufacturing, Quality Assurance, Quality Control, Sensory profile, specific descriptive attributes, or acceptance, depend-
Evaluation, and so forth. ing on the chosen testing method.
6.6 Determine Product Amount Needed to Conduct the Test
6. Procedures
for each Evaluation Point—Calculate the amount of product
6.1 Select Criteria to Determine the End-Point—Determine needed for each test.
the specific type of shelf life end point that will be used. There
6.7 Select Storage Conditions:
are three types of end points: (1) the product’s overall sensory
6.7.1 Typical Storage Conditions—Products selected to be
profile has changed; (2) a product attribute(s) that is known or
representativeoftheproductsingeneralshouldbestoredunder
suspectedtobekeytotheconsumers’perceptionoftheproduct
environmental conditions that represent the typical product
haschanged;and (3)theacceptabilityoftheproductistoolow.
distribution channel, and may include variations in
Company policy/objectives, marketplace conditions, business
temperature, humidity, light, atmosphere, air pressure, and
considerations, and risks all contribute to determining the type
environmental cycling (freeze/thaw, elevated temperature
of shelf life end-point.
conditions, and so forth).
6.2 Identify the Test Method to be Used—Thisisdoneonthe
6.7.2 Extreme Storage Conditions—Estimates of environ-
basis of the chosen type of shelf life end-point criteria.
mental extremes and time spent in the various stages of
Discriminationtesting,descriptive,oraffectivetestingmethods
distribution can help determine appropriate conditions. Verifi-
are the three major test method options.
cation of test storage conditions through the use of sensors or
monitors is suggested, especially if ambient storage conditions
6.3 Clearly Determine the End Point—The end point is
are selected.
established as either a significant overall difference from the
6.7.3 Accelerated Storage Conditions—Accelerated tests at-
control or a significant change in the intensity of one or more
tempt to achieve changes in product characteristics in a short
critical product attribute(s) or a significant decrease in accept-
period of time. Such tests can be valuable time savers if
ability to a predetermined level of acceptance The statistical
appropriately selected. However, these tests are only approxi-
criteria for measuring significance should also be included in
mations of how a product may behave under normal storage
the end point definition (that is, α, β, and the effect size) along
conditions. During accelerated storage, product changes may
with the number of panelists needed at each testing interval.
take place, or characteristics may develop that would not be
6.4 Select Control—Choose the type of control product that
typicalotherwise.Elevatedtemperaturesorexposuretohumid-
will be used for the study:
ity or light sources may cause different enzymatic reactions (or
6.4.1 Option 1—Stable Control—This is a typical product
similar reactions but to very different degrees) than would
that is held under conditions that minimize changes over time,
ordinarily occur under normal storage conditions. Uses of
such as frozen or refrigerated storage or modified atmosphere.
accelerated conditions are often based on untested “rules of
If no storage condition is known to keep changes to a
thumb”orbeliefsratherthanempiricaldata.Useofaccelerated
minimum,thistypeofcontrolcannotbeused.Ifdiscrimination
conditions is thus recommended only when solid research has
testing is the chosen method, this ty
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