Food flavor is hugely important in motivating food choice and eating behavior. Unfortunately for research and communication about flavor, many languages' flavor vocabularies are notoriously variable and must be aligned before data collection using training or after the fact by researchers. This dissertation demonstrates one example of each approach (conventional descriptive analysis (DA) and labeled free sorting, respectively), and compares their use to emerging, computational natural language processing (NLP) methods that use large volumes of existing text data. Rapid methods that align flavor vocabulary after data collection are most similar to NLP, and with the development or improvement of some strategic tools, NLP is well-poised to further accelerate the analysis of existing text data or unaligned vocabularies. DA, while much more time-consuming, ensures that the researchers, tasters, and readers have a shared definition of any flavor words used, an advantage that all existing rapid methods lack. With a greater understanding of how this differs from everyday communication about flavor, future researchers may be able to replicate this aspect of DA in novel descriptive methods. This dissertation investigates the flavors of specialty beverages, specifically American whiskeys and cold brew coffees. American whiskeys differ from other whiskeys based on raw materials and aging practices, with the aging practices primarily setting them apart. While the most expensive American whiskeys are similar to Scotches and dominated by oaky, sultana-like flavors, only very rich consumers desire these flavors, with chocolate and caramel being the most widely preferred by most consumers. Degree of roasting has more of an impact on cold brew coffee flavor than the origin of the beans, and the coffee consumers surveyed here preferred dark roast to light roast cold brews. / Doctor of Philosophy / Food flavor is hugely important in motivating food choice and eating behavior. Unfortunately for research and communication about flavor, many languages' flavor vocabularies are notoriously inconsistent: flavor words may have more than one meaning, multiple words may mean the same thing, and people regularly make mistakes when naming flavors. To get around this, researchers can either train human tasters to use a fixed set of flavor words, or they can attempt to identify the flavors that people are talking about from their own-words descriptions. In this dissertation, I give examples of both of these methods and compare them to approaches based on machine learning and other computational techniques. This dissertation investigates the flavors of specialty beverages, specifically American whiskeys and cold brew coffees. American whiskeys differ from other whiskeys based on raw materials and aging practices, with the aging practices primarily setting them apart. Producers wanting to set their whiskeys apart with the use of specialty or heritage grains will likely need to work with breeders to develop new varieties that will impart special flavors to the whiskeys. While the most expensive American whiskeys are similar to Scotches and dominated by oaky, sultana-like flavors, only very rich consumers desire these flavors, with chocolate and caramel being the most widely preferred by most consumers. For cold brew coffees, degree of roasting has more of an impact on flavor than the origin of the beans, although a subset of people sense and prioritize origin-related flavor differences when making flavor groups. The coffee consumers surveyed here preferred dark roast to light roast cold brews, which suggests that different beans are ideal for making well-liked cold brew coffee than traditional hot brew.

Cette thèse est consacrée à l’étude du café « Bourbon Pointu », Coffea arabica var. laurina, né d'une mutation spontanée de la variété Bourbon à l’île de La Réunion. Les teneurs moyennes des composés majoritaires non volatils du café vert sont (pourcentage de matière sèche) les suivantes : saccharose (7,1), trigonelline (1,3), caféine (0,75), acide caféoyl-5- quinique (4,7), acide palmitique (5,0), acide linoléique (6,5). L’analyse sensorielle a permis de mettre au point un profil de torréfaction original de courte durée. Parmi les 145 composés volatils extraits des poudres de café torréfié par SPME, cinq sont majoritaires (teneurs moyennes en ppm): acide acétique (34), 2-furaneméthanol (117), 5-méthyl-2-furfural (166), furfural (144), 2-méthylpyrazine (47). Ces cinq composés volatils extraits par SPE se retrouvent dans le café en tasse : acide acétique (23), 2-furaneméthanol (405), 5-méthyl-2-furfural (36), furfural (85), 2-méthylpyrazine (73) avec en plus, la -butyrolactone (97). Le ratio entre la concentration de la molécule et son seuil de perception définit l’Odor Activity Value (OAV). La conversion des concentrations des composés volatils en unités OAV a permis de dégager neuf molécules ayant un impact olfactif important : 2-furfurylthiol (café torréfié), 2-méthylpropanal (chocolat), dodécanal (agrume), 2-éthylhexan-1-ol (agrume), -pinène (boisé, agrume), furfural (boisé, caramel), 2-hydroxy-3-méthylcyclopent-2-én-1-one (érable), hex-2-énal (pomme verte), 2-méthylbut-2-énal (fruité, vert). La détermination de ces OAV a permis de différencier les trois catégories commerciales au niveau olfactif avec la prédominance d’aldéhydes pour les « Grand cru », le phénylacétaldéhyde pour les « Sublime », et les pyrazines pour les « Authentique ». Les conditions géoclimatiques et les transformations post-récoltes influencent de façon non négligeable la composition chimique du café vert et donc les arômes générés lors de la torréfaction et en conséquence, la répartition des cafés dans les trois catégories. L’ensemble de ces résultats fait du «Bourbon Pointu», un café haut de gamme classé parmi les «cafés gourmets». / This thesis is devoted to the study of “Bourbon Pointu” coffee, Coffea arabica var. laurina, born from a spontaneous mutation of the Bourbon variety in Reunion Island. The mean contents of non-volatile main compounds of green coffee are (percentage of dry matter): sucrose (7.1), trigonellin (1.3), caffeine (0.75), cafeoyl-5-quinic acid (1.7), palmitic acid (5.0), linoleic acid (6.5). Sensory analysis allowed to develop an original short time roasting profile. Among the 145 volatiles compounds extracted from roasted coffee powders by SPME, the mean contents of the five major components (ppm) are: acetic acid (34), 2-furanmethanol (117), 5-methyl-2-furfural (166), furfural (144), 2 methylpyrazine (47). These five volatile compounds extracted by SPE are found in the brew coffee: acetic acid (23), 2-furanmethanol (405), 5-methyl-2-furfural (36), furfural (85), 2- methylpyrazine (73) plus -butyrolactone (97). The ratio of molecule content to its perception threshold defines the “Odor Activity Value” (OAV). The conversion of the contents of volatile compounds in units OAV emphasized nine molecules with an important olfactory impact: 2-furfurylthiol (roasted coffee), 2-methylpropanal (chocolate), dodecanal (citrus), 2-ethylhexan-1-ol (citrus),-pinene (woody, citrus), furfural (woody, caramel), 2-hydroxy-3-methylcyclopent-2-en-1-one (maple), hex-2-enal (green apple), 2-methylbut-2- enal (fruity, green). The determination of these OAV differentiated the three commercial categories related to their typical odor due to the predominance of aldehydes for the "Grand cru", phenylacetaldehyde for "Sublime" and pyrazines for "Authentic". Geoclimatic conditions and post-harvest processing have a significant influence on the green coffee composition, on the flavors generated during roasting and thus, on the coffee distribution in the three categories. All these results define the "Bourbon Pointu" as a premium coffee and classify it as a "specialty coffee."