Exploring the Taste of Electronic Cigarettes - Aerosol Chapter (3): Aerosol Movement, Sedimentation Characteristics, and Sensory Experience

Exploring the Taste of Electronic Cigarettes - Aerosol Chapter (3): Aerosol Movement, Sedimentation Characteristics, and Sensory Experience
This article introduces the movement and deposition characteristics of electronic smoke aerosols in the respiratory tract, as well as their impact on sensory experience. Aerosols can bring sensory experiences such as aroma, taste, coolness, and stimulation. The movement path and deposition characteristics of aerosols are influenced by the suction method. The small circulation suction method mainly keeps aerosols in the oral cavity, while the large circulation suction method allows aerosols to pass through the complete respiratory system. Different suction methods can lead to different sensory experiences, and understanding these characteristics can help with better sensory evaluation and product improvement.
In the previous issue, we learned about the basic parameters and motion deposition characteristics of aerosols. In this issue, we will introduce the motion, deposition characteristics, and sensory experience of aerosols in the respiratory tract.
Topic 3 Aerosol Movement, Sedimentation Characteristics and Sensory Experience
(1) What sensory experiences can aerosols bring?
① Aroma. Guidelines for Sensory Evaluation of Electronic Cigarettes (II): Odor Perception and Olfactory Fatigue. This article introduces how we use our sense of smell to sense the aroma in aerosols during smoking. Interested friends, please click to go.
② Taste. Our taste buds in the mouth receive stimulation and further form taste perception. The taste buds mainly concentrate on the tongue and also exist on the inner surface of the oral cavity, such as the oral wall and throat. The currently recognized five basic flavors are sweet, sour, bitter, salty, and fresh.
③ Cool sensation. The cooling agents in aerosols do not actually lower the temperature in our respiratory tract, but directly trigger temperature sensors, thereby producing a sense of coolness. In addition to the oral and nasal cavities, our throat and some respiratory tracts can also produce a cool sensation.
④ Stimulation. Here, it mainly refers to the "throat sensation", which is produced by nicotine (or nicotine salts) stimulating the mucous membranes of the respiratory tract and throat. Usually described as a stimulus.
⑤ Visual, auditory (the sound produced by atomizers during aerosol production), etc. Not discussed in this series.
(2) Aerosol movement and deposition in the respiratory tract
The previous article introduced the particle size distribution of aerosols deposited in the respiratory tract. In this issue, we will set aside specific particle size values and analyze our sensory experience of air soluble tape from a holistic perspective. Therefore, in this article, aerosols with larger particle sizes are called large particles, while aerosols with smaller particle sizes are called small particles. The concepts of large and small are relative.
Exploring the Taste of Electronic Cigarettes - Aerosol Chapter (3): Aerosol Movement, Sedimentation Characteristics, and Sensory Experience
We can see that when using small circulation for suction, the aerosol only passes through the oral cavity (accompanied by a small portion of the upper respiratory tract area); When using a large circulation for suction, aerosols pass through the complete respiratory system.
(3) How the movement and deposition of aerosols affect sensory experience
① Aroma.
When using small circulation inhalation, both large and small particles briefly stay in the oral cavity, and then exhale through the nasal cavity. The vast majority of aerosols will pass through olfactory receptors, and the nasal cavity will feel a very strong aroma. When using large circulation inhalation, some large particles deposit in the oral cavity, while the remaining aerosols pass through the respiratory tract and gradually decrease before reaching the lungs. Then, the lungs contract and squeeze out the aerosols in the respiratory tract, which are exhaled through the nasal cavity. Due to the deposition of aerosols in various parts of the respiratory tract, the aroma felt in the nasal cavity will be weaker than in the small circulation under the same inhalation amount.
② Taste.
When using small circulation inhalation, due to the prolonged residence of aerosols in the mouth, the tongue's perception of sweetness and sourness will be more pronounced, and similarly, its perception of bitterness will be more pronounced. Therefore, when determining whether aerosols are bitter, this suction method will be more sensitive. When using large circulation inhalation, some small particles enter the throat and lungs through the respiratory tract, and the amount of aerosols in contact with the tongue and mouth decreases, so the perception of taste will be weaker than that of small circulation. Furthermore, it is highly anticipated whether the "freshness" can be felt through electronic smoke aerosols.
③ Cool sensation.
When using small circulation inhalation, only the nasal and oral cavities will produce a cool sensation; When using large circulation inhalation, our mouth, nose, throat, and some respiratory tract can be activated by the cooling agent carried by aerosols, which can generate a sense of coolness. Therefore, large circulation can effectively evaluate the coolness of aerosols from a holistic perspective.
④ Stimulation.
When using small circulation inhalation, the throat dominant stimulation cannot be felt; When using large circulation inhalation, both large and small particles will pass through the throat and nearby respiratory tract in large quantities, producing a "throat sensation". This feeling allows e-cigarette users to enjoy the pleasure of smoking more, thereby increasing their dependence on nicotine intake
The different suction methods determine the movement path of aerosols, and different movement paths determine different sensory experiences. Understanding the movement path and deposition characteristics of aerosols will help us better conduct sensory evaluation and product improvement and upgrading. In addition, when encountering specific problems (such as sweetness evaluation and coolness evaluation), one can choose the corresponding suction method to obtain sensory information more accurately.