Consumer-Based Product Profiling: Application of Partial Napping® for Sensory Characterization of Specialty Beers by Novices and Experts

Abstract

Napping® is an inexpensive and rapid method for sensory characterization, suitable for both trained and untrained subjects. In the study presented, the method was applied on 9 specialty beers. Subjects were 17 consumers without any training as sensory panelists, of whom 8 were beer experts and 9 novices. The aim was to explore the usability of the Napping® method by untrained consumers and to analyze differences between beer novices and experts in their ability to discriminate and describe the products. The method succeeded in discriminating between the beers, revealing sensory descriptors responsible for the differences. Analysis of differences between the two groups showed that the experts had higher agreement with regard to sample differences (significantly higher mean RV-coefficient, 0.61 vs. 0.41 for non-experts, p = 0.013). The results support the usability of Napping® as a fast method for sensory characterization, with the advantage of providing a product characterization based on consumer descriptions, thus better reflecting consumers' experience with the product.

Keywords:

• Napping
• beer
• fast sensory methods
• sensory profiling
• consumers vs. experts

Acknowledgments

This study was funded through the industry-research consortium “Dansk Mikrobryg-Produktinnovation og Kvalitet.” We wish to thank to our colleagues Christian Dehlholm and Helene C. Reinbach for assistance with conducting the experiment and analyzing the data. The help of brewmaster Stefan Peter Stadler and Indslev Brewery with hosting one of the experimental sessions is also thankfully acknowledged.

Notes

¹ Unlike the original Projective Mapping technique, where an A4 sheet with two crossed axes was used (Risvik et al., 1994).

² In the version used for this study—which is the one proposed by the method developers (Pagès & Husson, 2001; Pagès, 2005)—the scaling factor is the first eigenvalue of a separate PCA performed on each individual configuration.

³ With regard to the beers in clusters 1 and 2, it should be acknowledged that the subjects might have been influenced by the color (though they were instructed to concentrate only on smell and taste), since clear glasses were used during the Napping task. The color of a product is known to affect the perception of other sensory characteristics (Lawless & Heymann, 2010). The sensory descriptors elicited, however, match our previous knowledge of the samples and the commercial descriptions by the producer.