Characterizing product temperature-dependent sensory perception of brewed coffee beverages: Descriptive sensory analysis

In most previous studies, brewed coffee samples were served at specific serving temperatures for sensory evaluation. While several recent studies have illustrated that serving temperature does have an impact on sensory attribute intensities of brewed coffee, more elaboration is needed. By focusing on knowledge gaps between earlier studies, this study sought to determine whether and how sensory attributes of brewed coffee can vary as a function of serving temperature and coffee variety. In this study, 6 trained panelists rated intensities of 32 sensory attributes (3 appearances, 12 aromas, 2 tastes, 13 flavors, and 2 mouthfeels) with respect to brewed coffee samples, of each of three varieties (Ethiopian, Kenyan, and Colombian) served at four different serving temperatures: 70, 55, 40, and 25 degrees C, respectively. The results indicated that intensities of 18 and 7 attributes, respectively, differed significantly with serving temperature and coffee variety. A principal component analysis (PCA) showed the greater amount of data variation could be attributed to serving temperature (63.28%) rather than coffee variety (21.24%), much like the result of a hierarchical clustering analysis. Regression vector (RV) coefficients, determined by a factor score matrix of brewed coffee samples served at different temperatures, revealed that brewed coffee samples served at 70 and 55 degrees C were perceived differently from those served at 40 and 25 degrees C. In conclusion, the findings emphasize that sensory attributes of brewed coffee samples should be evaluated at multiple serving temperatures, both higher (70 to 55 degrees C) and lower (40 to 25 degrees C) ones, to better capture sensory attributes of brewed coffee than those from a traditional sensory evaluation. Further study is needed to characterize different coffee samples with respect to lessening an overwhelming effect of serving temperature.