J.C. Pfeiffer and C.C. Gilbert
Campden & Chorleywood Food Research Association, UK


There has been a renewed interest recently for methods that allow the acquisition of perceptual maps without having to resort to conventional profiling, an objective in line with the needs of the industry for cheaper, quicker and simpler sensory testing. Indeed, increased pressure on product innovation and tighter developing times means that conducting traditional sensory analysis may no longer be viable in a lot of business cases (for product development for instance).

This study aimed to address the question of using the Napping® technique (Pagès 2005) with a trained panel when the objective is to sort a large number of samples prior to more in-depth analysis.

Two sets of commercial products varying in degree of sensory complexity were chosen for this investigation (strawberry yoghurt and sliced white bread). Eight descriptive panellists carried out both Napping and conventional profiling to allow for comparison of the methods. Statistical analysis was carried out using Principal Component Analysis and Multiple Factor Analysis.

The Napping technique proved to be a very simple way to obtain a quick perceptual map of the sample sets. When compared with conventional profiling, it was apparent that the two methods were close in terms of product characterisation and led to similar sample spaces. However, the study showed product specificity, where Napping was more applicable to the yoghurts and conventional profiling better characterised the breads. This was further linked to the recurrent question of holistic (synthesising all sensory information available) versus analytic (separating products’ properties into independent attributes ) sensory evaluation. Results and general observations will be discussed.

Pagès, J. (2005) Collection and analysis of perceived product inter-distances using multiple factor analysis: Application to the study of 10 white wines from the Loire Valley. Food Quality and Preference, 16, 642-649.