Table 1.

Physical design features and chemosensory characteristics

Cigarette Design Features
Filter design:	Ventilation	Vent holes strategically placed in the filter to allow entry and mixing of air with cigarette smoke. Enhances perceptions of smoothness. Reduces other sensory characteristics, such as taste.
	Resistance to draw	Physical resistance to the passage of air and/or smoke through the cigarette and into the mouth
	Carbon filter	Reduces particulate phase constituent yields and may enhance smoothness
Cigarette rod design:	Rod circumference	Tobacco rod circumference influences resistance to draw and burn temperature
	Tobacco blend	Proportions of Virginia, burley and oriental tobaccos, either air or flue cured, and intended to convey greater flavor characteristics or nicotine delivery
Smoke constituent delivery:	Nicotine delivery	Nicotine delivered via mainstream smoke to the smoker
	Tar delivery	Tar delivered via mainstream smoke to the smoker
	Gas phase constituents	Mainsteeam smoke constituents in gas phase at the time of delivery, including nicotine, volatile organic, carbonyl and phenolic compounds
	Particle size	Smaller tobacco smoke particles enhance perceptions of smoke smoothness and reduce perceptions of draw effort and risk
Additives:	Ammoniation	A strategy to modify pH which increases the proportion of unprotonated to protonated nicotine
	n-hexadecane	Alkane hydrocarbon used to enhance mouthful and body
	potassium carbonate	Alkaline salt compound added to tobacco to enhance mouthful/mouthfeel
Sensory Characteristics
Draw effort:	Draw effort/ Perception of draw	Perceived amount of effort required to draw a satisfactory amount of smoke from the lit cigarette into the mouth
Harshness-smoothness balance:	Harshness	Sensory characteristics with higher impact and irritation effects
	Smoothness	Sensory characteristics with lower impact and irritation effects
	Impact (throat/chest)	A sudden, sharp, but short-lived sensation felt upon the back of the throat upon inhalation (BAT, 570354096/4354)
	Irritation	A more persistent sensation than impact, in which the intensity of prickling, tingling, itching and similar sensations build up and slowly fade away (BAT, 570354096/4354)
Non-irritant sensory And subjective responses:	Pleasure	A term generally understood by smokers to imply nicotine effects; the subjective interpretation of nicotine reward or reinforcement
	Satisfaction	See pleasure
	Flavor	A combination of perceived sensory characteristics taste, odor, and touch
	Strength	Magnitude of flavor characteristic
	Acceptance	“Perceived fullness of smoke, and not just particular taste or quality perceptions.” Basis for consumer product preference.
	Palatability	The presence or absence of desirable flavor characteristics, including flavor strength and harshness-smoothness balance
	Mouthful	“The impression of volume or amount of smoke entering the mouth and occupying the mouth during puff taking” (Ayya et al., 1995)
	Mouthfeel	See mouthful
	Body	See mouthful