Spectrum Descriptive analysis overview
Descriptive analysis methods began with the Flavor Profile Method (Caul, 1957)1 developed by the Arthur D Little Company in the early 1950s. Several food and pharmaceutical companies developed Flavor Profile panels over the next several decades. General Foods [now a part of Kraft] maintained several Flavor Profile panels for research and development and for quality purposes and began to change the Flavor Profile Method to adapt it to the various products and applications that needed detailed flavor descriptions. These adaptations included modifications such as: expanding the Flavor Profile 7 point scale to 14 points; using a control sample as a calibration sample in each tasting session; using intensity references as well as references for the terms or attributes used in the description; training panelists extensively and validating them for use on specific product testing; providing rigorous treatment of product procurement and preparation to insure product sampling integrity.
In addition, the Texture Center at General Foods was developing the Texture Profile Method, based on the Flavor Profile method and underpinned by the texture technology developed by Alina Szcsesniak and her team (Szczesniak, 1963)2; (Szczesniak, Brandt and Friedman, 1963)3; (Civille and Szczesniak 1973)4. With this foundation in Flavor and Texture Profile understanding and application to documenting products in development and operations, Gail Vance Civille developed the Spectrum™ Descriptive Analysis method during the 1970s and presented the method at the 3 IFT Sensory Evaluation Courses in 1979. The Spectrum Method incorporates the rigor of the training and structure of the Flavor and Texture Profile Methods and then adds a more refined scale [over 150 points of discrimination]; application of statistical methods to the descriptive data; and expansion to products outside of food and beverage, such as personal care products [both skinfeel and fragrance] and paper and fabrics [both fragrance and tactile feel]. (Meilgaard, Civille, Carr, 2007)5
In the last 20 years the Spectrum™ Descriptive Analysis Method has been used in government labs to document the sensory properties of commodities and products that use commodities. Academia uses the Spectrum™ Method to monitor and track basic and applied research in foods, personal care and paper products. However, the bulk of the application of the method is in R&D departments of consumer product companies globally to document the sensory properties for product development and quality control with accuracy and reliability.
The Spectrum™ Method supports the interest of product developers who need a clear documentation of a product attributes and their intensities that allows product profiles to be compared across products and across time with the same level of confidence the researcher expects from instrumental data. Descriptive analysis data should provide a product profile that allows the product developer to see the direction that process, ingredients or time have had on the product’s sensory characteristics.
1 Caul JF (1957). The Profile Method of Flavor Analysis. Adv Food Res, 7: 1-40
2 Szczesniak AS (1963). Classification of Textural Characteristics. J Food Sci, 28:4, 397
3 Szczesniak AS, Brandt MA and Friedman HH (1963). Development of Standard Rating Scales for Mechanical Parameters of Texture and Correlation between the Objective and the Sensory Methods of Texture Evaluation. J Food Sci, 28:4, 397-403
4 Civille GV and Szczesniak AS (1973). Guidelines to Training a Texture Profile Panel. J Texture Stud, 4: 204–223
5 Meilgaard MC, Civille GV, and Carr BT (2007). Sensory Evaluations Techniques, CRC Press, Boca Raton, FL