A novel method of descriptive analysis on hot brewed coffee: time scanning descriptive analysis

Dynamic Instrumental and Sensory Methods Used to Link Aroma Release and Aroma Perception: A Review

Perception of flavor is a dynamic process during which the concentration of aroma molecules at the olfactory epithelium varies with time as they are released progressively from the food in the mouth during consumption. The release kinetics depends on the food matrix itself but also on food oral processing, such as mastication behavior and food bolus formation with saliva, for which huge inter-individual variations exist due to physiological differences. Sensory methods such as time intensity (TI) or the more-recent methods temporal dominance of sensations (TDS) and temporal check-all-that-apply (TCATA) are used to account for the dynamic and time-related aspects of flavor perception. Direct injection mass spectrometry (DIMS) techniques that measure in real time aroma compounds directly in the nose (nosespace), aimed at obtaining data that reflect the pattern of aroma release in real time during food consumption and supposed to be representative of perception, have been developed over the last 25 years. Examples obtained with MS operated in chemical ionization mode at atmospheric or sub-atmospheric pressure (atmospheric pressure chemical ionization APCI or proton-transfer reaction PTR) are given, with emphases on studies conducted with simultaneous dynamic sensory evaluation. Inter-individual variations in terms of aroma release and their relevance for understanding flavor perception are discussed as well as the evidenced cross-modal interactions.

Does Coffee Have Terroir and How Should It Be Assessed?

The terroir of coffee is defined as the unique sensory experience derived from a single origin roasted coffee that embodies its source. Environmental conditions such as temperature, altitude, shade cover, rainfall, and agronomy are considered the major parameters that define coffee terroir. However, many other parameters such as post-harvest processing, roasting, grinding, and brewing can combine to influence the perception of terroir. In this review, we discuss the contribution of these parameters and their influence on coffee terroir. Assessment of terroir requires defined sensory descriptors, as provided by the World Coffee Research Lexicon, and standardized roast level, grind size, and brew method. The choice of the post-harvest processing method is often environmentally dependent, suggesting that an inclusion into the coffee terroir definition is warranted. Coffee terroir is often not intentionally created but results from the contributions of the Coffea species and variety planted, environmental and agricultural parameters, and both the harvest and post-harvest method used. The unique combination of these parameters gives the consumer a unique cup of coffee, reminiscent of the place the coffee was produced.

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 °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 °C were perceived differently from those served at 40 and 25 °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 °C) and lower (40 to 25 °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.

Influences of Product Temperature on Emotional Responses to, and Sensory Attributes of, Coffee and Green Tea Beverages

Coffee and green tea are popular beverages consumed at both hot and cold temperatures. When people consume hot beverages concurrently with other activities, they may experience at different temperatures over the period of consumption. However, there has been limited research investigating the effects of product temperatures on emotional responses and sensory attributes of beverages. This study aimed to determine whether emotional responses to, and sensory attributes of, brewed coffee and green tea vary as a function of sample temperature. Using a check-all-that-apply (CATA) method, 157 participants (79 for coffee and 78 for green tea) were asked to evaluate either coffee or green tea samples served at cold (5°C), ambient (25°C), and hot (65°C) temperatures with respect to emotional responses and sensory attributes. The results showed that sample temperature could have significant influences on emotional responses to, and sensory attributes of, coffee and green tea samples. More specifically, 6 and 18 sensory attributes of coffee and green tea samples, respectively, significantly differed with sample temperature. Beverage samples evaluated at 65°C were characterized, regardless of activation/arousal level, by positive emotional responses terms and favorable sensory attributes. While beverages evaluated at 25°C were associated more with negative emotional responses with low activation/arousal, those evaluated at 5°C were more frequently characterized as having negative emotional responses with high activation/arousal. Sensory and emotional drivers of liking for both coffee and green tea differed both with sample temperature and gender. While both emotional responses and sensory attributes were identified as drivers of liking among females, only emotional responses were identified as drivers of liking among males. In conclusion, this study provides empirical evidence that both emotional responses to, and sensory attributes of, coffee and green tea beverages can vary with sample temperatures. To provide a better understanding of product characteristics, emotional responses to, and sensory attributes of, coffee or green tea beverages should be tested over a wider range of product temperatures.