The modern consumer of hair care products is a demanding and discerning
buyer. Some examples of the available evaluation methods as tools of
efficacy substantiation of hair care products are described. The methods
have been classified in three main categories, ranging from
instrumental to sensory procedures. An example of instrumental
investigation is the evaluation of anti-dandruff efficacy and the
phototrichogram technique. The phototrichogram enables identification of
the hair in a growth phase by a series of photos taken in succession of
a delimited and shaved scalp area. It also allows determination of the
hair growth rate. There are three main procedures to assess
anti-dandruff efficacy: gravimetric assessment, counting technique and
direct assessment. Salon testing represents the most suitable way to
obtain specific information on product performance. The evaluation is
made by an expert professional hairdresser. Sensory Analysis is a method
which enables analysis of the sensory response to a specific stimulus
in a qualitative and quantitative way. Sensory Techniques are classified
in two categories of tests, which differ in factors such as type of
questions, panellists´ training and type of response required:
discriminative tests and descriptive tests. Sensory tests focus on the
quali-quantitative components of the sensory response, affective tests
concern its hedonic aspects.