Table 2: applications of sensory analysis
can use to evaluate freshness and quality of a
product. Apples and carrots for example should
be crunchy while potato chips should be crispy.
The Role of Sensory in
Quality Assurance
Table 2 shows a number of possible applications
of sensory analysis. For these applications
different test methods are used.
The simple descriptive test according to DIN
10964 for example is used to verbally describe
characteristics of a product. This test is used to
determine influencing factors of production or
to characterize a product standard. It is therefore
also used as a basis for specific evaluation
schemes, for example for profile testing.
The triangle test according to DIN EN ISO
4120 is for example used if a recipe has been
changed or if there have been changes in production
process, packaging material or storage
conditions. The testers get a set of three samples.
Two of these samples are identical while
one differs, for example 2 samples of the old
and one sample of the new recipe. With the
right amount of testers it is possible to statistically
evaluate if a difference between both
products can be perceived by consumers.
According to DIN EN ISO 5495 (§ 64 LFGB L
00.90-8) the paired comparison test is a method
to determine the difference in one characteristic
of two samples. These samples have one noticeable
difference or similarity, which must be identified
by the testers. So it is possible to check which
characteristic property like e.g. acid or sweetness
is more pronounced in one sample compared to
the other one, which is mainly useful for product
development or comparison with competitor
products. It is a “Forced-Choice” testing, so all
testers must choose one of the two samples, even
if they cannot perceive a difference between the
samples. There are two different types of this test
method, one-sided and two-sided. For one sided
test the difference is known, and the testers have
to decide in which of the two test samples the
characteristic property is more pronounced. On
the other hand in two-sided test, the testers do
not know the difference and have to decide which
one they prefer.
The profile test according to DIN10967-1
(§ 35 LMBG L 00.90-11/1) is used for identification
from selected attribute properties, which are
assessed based on their intensity. This could be
done for specific characteristics for each product
individually. In figure 2 such profile is shown for a
roasted coffee. This method is often used for characterization
of product standards, comparison of
multiple products, recording of recipe changes
and product development and optimization.
Especially if the consumer acceptance of a
product in relation to comparable products a
consumer panel can be useful and informative.
Hereby randomly selected and untrained persons
will do sensory of the products in comparison
with competitor products. The producer
gets a direct feedback and ranking how acceptable
and fine their product is in comparison to
similar products on the market. Also this method
is used for general research of consumers.
Expert Assessment
Sensory analysis is also very important to determine
the variety of plant products like tea or
coffee. Trained and experienced tasters can
identify variety and even geographical origin
by sensory properties of the product. For such
sensory analyses and evaluations testers do not
just need to be trained according to DIN EN ISO
Product development
Review of quality assurance processes
Authenticity check
Testing of product stability during processing
Determination of the best before date
Identification of off-flavours, for example through the packaging
Identification of product defects
Figure 2: typical profile for roasted coffee
Figure 3: honey odour and aroma wheel 4
Sensory Analysis 21