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Chapter 3 Sensory Evaluation: The Human Factor
system. Whenever possible, arrange tasting stations in a circle with
class members facing outward. This will reduce the accidental
infl uences of others’ facial expressions.
Controlling Environmental Factors
Environmental factors that should be controlled during taste tests
include lighting and aromas in the testing room. Using colored lights
during taste testing will not be possible in most classrooms. However,
you can make sure light levels are similar in all testing areas. If masking
color is important in a test, you can use blindfolds, 3-8.
Aromas present in the classroom can strengthen or weaken
your response to any given food. Suppose you eat a cooled chocolate
chip cookie in a kitchen where more cookies are baking in the oven.
You will be exposed to more volatiles in this setting than if you eat
the same cookie in another place. You can control this variable to some
extent by tasting samples the day after they are prepared.
Because tastes and aromas can linger, you should take a sip of
warm water between each sample you taste. Professional taste testers
do this to help rinse any food residue from the mouth. The water
needs to be warm to help remove any fats that may be present. Cold
water can cause fats to cling to the tongue rather than wash away.
Because fat is very fl avorful, this step is critical in any food taste test.
You might also eat plain soda crackers to help clear fl avors from the
mouth between food samples.
Another factor that should be controlled is the temperature
of the food samples. Tests on perceiving sweetness show that
maximum sweetness is perceived at different temperatures for
different sweeteners. Maximum sweetness scores for table sugar
are recorded at a temperature of 25°C (77°F). This is within normal
room temperature ranges.
To help control this variable,
have all samples at the same
temperature. Take all chilled
samples from the refrigerator
at the same time. Also, allow
baked goods time to reach room
temperature before sampling.
Controlling
Psychological Biases
Psychological biases can affect
the way test panelists respond to
various food samples. For instance,
test samples are usually identifi ed
by codes. However, human
response studies have shown that
most people prefer samples with
Janet Ward
3-8 Wearing a blindfold helps this student more accurately measure his
tasting ability. A partner hands him each sample and records the responses.