Overview of Descriptive Analysis
The aim of all descriptive techniques is to generate quantitative data which describes the differences among a set of products. Each method has a slightly different approach to solving the same problem; however the basic framework of all the techniques is the same:
- selection of panel members
- term generation (or selection of appropriate lexicon)
- concept formation
- testing of panel consonance
- evaluation of products
Descriptive techniques include Free Choice Profiling (FCP), the Spectrum™ method, Quantitative Descriptive Analysis™ (QDA), Flavor Profile Method, Texture Profile Method, Flash Profiling and generic descriptive analysis. Generic descriptive analysis generally takes pieces from QDA and Spectrum™ methods, but is tweaked to suit the goals of the project and limitations of the product being tested. Of the methods mentioned here, FCP and Flash Profiling involved the use of untrained consumers rather than a trained panel (although a trained panel can be used). This main point of differentiation makes these techniques faster and cheaper to conduct as there is no training involved.12
Panel Selection
The selection of panel members is very important to the quality of the data obtained. Potential members need to be screened for their ability to discriminate between similar samples, rate products for intensity and identify tastes and aromas. Equally, or possibly more, important than a panelists’ sensory acuity is their motivation. A panelist who feels they are required to particiapte may not perform as well as and equally skilled panelist who feels motivated to participate.
Panel Training
Panel training encompasses term generation, concept alignment and panel testing phases. The amount of training required is dependent upon the method used as well as the product(s) to be tested.3 A company with an in-house descriptive panel may spend several months or more training a panel over a wide range of products, rather than training the panel specifically for each product as needed.
Notes
1 Lawless, H. and H. Heymann (1998). Sensory Evaluation of Food: Principles and Practices. New York, Kluwer Academic/Plenum Publishers.
2 Murray, J. M., C. M. Delahunty and I. A. Baxter (2001). Descriptive Sensory Analysis: Past, Present and Future. Food Research International, 34: 461-471.
3 Chambers, D. H., A.-M. A. Allison and E. I. Chambers (2004). Training Effects on Performance of Descriptive Panelists. Journal of Sensory Studies, 19: 486-499.
