Characterisation of the volatile sensometabolome in human breath of cigarette smokers, electronic cigarette users and non-smokers by Aroma Extract Dilution Analysis

Smokers are known to have a characteristic smelling and long-lasting breath after the consumption of a cigarette. However, the responsible compounds for this malodour have not been fully explored yet. Therefore, the aim of the present study was to characterise key aroma compounds in the breath of cigarette smokers and compare the resulting aroma profile to electronic cigarette (EC) users’- and non-smokers’ (NS) breath before and after product consumption by application of aroma extract dilution analysis (AEDA) in combination with gas chromatography olfactometry (GC-O). Interestingly, the breath of cigarette smokers revealed a significantly higher intensity in the overall aroma, resulting in higher flavour dilution factors, in comparison to the breath of non-smokers or electronic cigarette users. This was predominantly caused by a high number of aroma-active pyrazines. Exhibiting an earthy, musty smell, these combustion products can still be found in breath one hour after smoking and are hypothesised to be responsible for the characteristic ‘ashtray’ smell. These findings align well with results of a study on cigar smokers’ breath by Bazemore et al. who suggest that due to their structure, pyrazines are trapped in both mucosa and saliva leading to a long-lasting ‘smokers-breath. In comparison, the breath of EC users revealed similar aroma profiles to the ones of NS even immediately after consumption. In doing so, these data suggest that EC use may have personal and social consideration benefits