Hair products evaluation: instrumental and sensory methods

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.