First developed by French academics in 2003, Napping works by getting assesors to position products on a large sheet of paper according to perceived similarities and differences (see picture) on what Campden BRI calls an “overall sensory basis”, with instructions to place similar products near one another and different products further apart.
Each assessor is free to decide the criteria - which may be instinctive or unconscious - used to separate the products, after which statistical analysis of their individual maps aggregates the product positions to produce a two-dimensional “consensus plane representation” of the sample set, to which the judges then add relevant descriptive terms.
Useful tool for NPD
UK-based Campden BRI revealed in a new research paper communicating the advantages of Napping to the industry that it has investigated the practicability of using the technique to assess commercial yogurts and white bread; it chose these on the basis that all the senses would be engaged by these products since odour, flavour, appearance, touch and mouth texture were all key.
However, the company admits that traditional sensory profiling – whereby a fixed set of descriptive terms is used by a panel to judge food or beverage characteristics – remains the “most effective and valuable tool” to obtain sensory information for use in NPD, recipe reformulation or quality improvements, although one key advantage of Napping is its ability to "highlight the relationship between products".
“[Traditional sensory profiling] is also the most complex to put in place in an industrial environment in terms of time and resources, as it requires the use of a panel of judges trained on a specific methodology,” which Campden BRI insists can take months, while maintaining consistent judging standards is difficult across an extended period of time.
Technique set for take off?
Asked about interest amongst the firm's worldwide membership, Chantal Gilbert from Campden BRI’s sensory team told FoodNavigator.com: “We are getting interest on two levels…mostly through our Sensory and Consumer panel, an industrial group of sensory scientists that we co-ordinate to share our research findings. They have followed our work on Napping…so that they can explore its use within their own companies.”
“But as the method gains more recognition, we envisage there will be more interest from product developers, for example, who can tap into the practical benefits [of the technique].”
Questioned on why the technique was particularly suited for the food and beverage industry, Gilbert said that it was ideal to use when sorting large sample sets, “prior to more in-depth analysis of selected samples”.
“An example could be to use the Napping method to screen a large number of new formulations in product development prior to conducting consumer research on the selected samples. Napping has the advantage of providing a fast, simple and cost-effective means of obtaining a sensory map of products.”
One variation on the technique is ‘partial Napping’, where the standard process is repeated while focusing on single sensory modalities such as appearance, odour, flavour and texture, which Gilbert said has the added advantage of “generating more descriptive information, allowing for easier interpretation of results, while it’s also easier for a descriptive panellist to carry out”.