76
Unit 1 The Science of Food
low numbers to samples with higher numbers. Likewise, people
tend to prefer samples labeled with letters near the beginning of
the alphabet. In other words, test panel members are likely to select
sample 1 over sample 3. They are also likely to select sample A over
sample B or C. When the order of samples is changed, panel members
still prefer samples labeled 1 or A.
Researchers in taste testing have found this bias goes away when
they use three-digit code numbers. For instance, people show no
preference for sample 527 over sample 619. When you test samples
in class, your teacher will randomly choose three-digit numbers to
identify each product. He or she will keep a key to correctly identify
each sample.
Another factor that can infl uence taste test panels is the number
of samples provided. The number of samples a taster can reliably
judge is limited. Four or fi ve samples seems to be the most that tasters
can evaluate at one time.
Tasters will tend to prefer the fi rst samples presented to later ones.
To help account for this factor, panelists will often taste the same
samples in different orders.
Creating an Evaluation Form
Test panel members need some kind of numerical scoring system
to rank food samples. Taste test panelists are often asked to rank
products on a scale of 1 to 5, 1 to 7, or 1 to 9. A smaller scale does not
allow enough choices to rank products. A numerical scale that goes
above 9 gives too many choices. An odd number of choices provides
a neutral point. This is the ranking respondents can use to indicate
they neither like nor dislike a product.
Universal Evaluation Form
When developing food products for children, manufacturers are likely to want some test panel
members to be children. Similarly, when developing products for an ethnic market, manufacturers
will want members of that market to be part of the test panel. A universal evaluation form solves
the problem of having some panel members who cannot read and write in the given language.
The following is an example of a testing form that could be used by any taste test panel member.
Tasters simply mark the box below the face that is closest to the way they feel about the food.
3-9 A universal evaluation form eliminates barriers that can be created by language on written forms.