SMELL: SMELL: SMELL: Orthonasal perception Orthonasal perception Orthonasal perception
As delivered by the retronasal Olfactory bulb route, smell dominates flavor.4 TASTE: TASTE: TASTE: Retronasal perception Simple tastes are hardwired Retronasal perception Retronasal perception from birth according to Olfactory Shepherd4 but retronasal AFTERTASTE: AFTERTASTE: epithelium AFTERTASTE: Retronasal perception Retronasal perception smells are learned Retronasal perception hairs and is thereby open to individual FIGURE 2 Smell and taste differences. The physiology and anatomy— bottom line here Orthonasal and retronasal is that we are all perceptions and air flow totally different in pathways. our aroma/flavor evaluation Full details are presented in the and thus training involves text. Briefly—in bright blue— getting everyone on the same “sniffing in” is orthonasal smell page with terminology— perception—and deals with an flavor descriptors, etc., and initial perception of a product’s Tongue understanding strengths, flavor profile. With orthonasal perception, during sensory evaluation weaknesses and even blind spots of a spirit, odor-laden air—the in flavor detection. One or two volatiles from the glass crosses the people evaluating a product is olfactory epithelium during breathing grossly insufficient and ineffective. in through the nostrils—the orthonasal When we train together and think or direct nasal passage. The reception through the epithelial hairs is perceived more carefully about our everyday via the olfactory bulb as the spirit’s “nose”.7 experiences and our product’s aromas/ The detection thresholds of compounds may flavor profiles we get better at our assessments and judgments. be different here compared to the later retronasal We must also realize that flavor does not reside in a flavorful perception. Next—in dark blue—taste (technically beverage—rather, flavor is actively created in the brain. “The smells flavor), via the backwards flow of volatile-laden air, is defined as retronasal perception. Finally, the lines in light that dominate the sense of flavor arise as differences between gray shows another backwards air flow carrying molecules across molecules; our brains represent those differences as patterns the olfactory epithelium to give a final burst of aroma (flavor) known and combine them with taste and other senses to create smells SMELL: as aftertaste. After swallowing a sample, the mouth and throat remain coated Orthonasal perception and flavors that have meaning for our perceptions of food (and in the flavor molecules of the food or drink just consumed. With breathing 4 beverages).” Furthermore, “Flavor is primarily the smell of gases out, the airflow carries some of the flavor in a retronasal mode and the associated sensation is often described as the strongest contributor to the released by the chemicals (the volatiles in the spirit) you’ve just TASTE: taste of the beverage. However, both orthonasal and retronasal perceptions 4 Retronasal perception put in your mouth” (attributed to E. Schlosser, cited in Shepherd ). contribute to the overall flavor profiling of a beverage. Summarizing our assessment of spirit volatile organic compounds (VOCs). Airflow dynamics are involved in how we assess the volatile AFTERTASTE: Retronasal composition of our spirits and wines. A summary3 reads: We can now reiterate perception that simple nosing of distilled spirits is not
Sniffing in orthonasal air currents—dealt with in the nose Breathing out retronasal air currents in the nose Breathing out movement of volatiles from the mouth Breathing out retronasal air currents moving from the pharynx (the membrane-lined cavity behind the nose and mouth connecting them to or from the esophagus)
Breathing stopped nasal cavity gated-closed during swallowing Breathing out airflow provides a “flavor-burst” and the aftertaste or finish after the swallow. For many tasters the “aroma- or flavorburst” is the strongest contributor to the taste of the beverage (Relate this listing to the actions portrayed in Figure 2).
enough to evaluate the flavor. Subjects trained to recognize smells (the preferred term should be “aromas”) via sniffing (orthonasally) had difficulties in recognizing them when they were specifically introduced at the back of the mouth. Attention must, therefore, be made to both sniffing and retronasal detection and evaluation of a product to better understand its composition and associated complexity of its flavor profile. It is now known that the human sensory anatomy evolved and has become adapted for enhancing retronasal smell.4 Despite those statements made a few decades ago that we can forget about the sense of smell and that it is not important to modern day human survival—hopefully we now see or smell the situation differently. At least for our enjoyment of our favorite foods and beverages! In evaluating a complex mixture of volatile or aromatic components, say in whiskey, we do, however, need to understand
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