Quantitative characterization of aerosol numbers, sizes, and mass in sweet carbonated beverages

Aerosol droplets fractured from beverages play a pivotal role in oral-nasal flavor transfer, acting both as carriers of aroma compounds and as amplifiers of surface area for volatile release. However, the absolute number and size distribution of these aerosol droplets, key determinants of their sensory impact, remain largely unexplored. This study quantified aerosol number and size (0.18-20 μm) with an optical particle counter (1.45 l/min) in both in vitro splashing/bubbling models and in vivo nostril-exhalation immediately after swallowing (n = 10). Transferred aerosol mass was measured by fluorescein-traced collection, while high-speed imaging characterized bubble bursting; surface tension and extensional rheology were profiled to rationalize mechanisms. Across carbonated sweet beverages, we observed substantial aerosol production carrying up to 9 % of aroma compounds relative to a 25 mL equilibrium headspace and enlarging exposed surface area by as much as 200 % versus a 30 mm beaker. Notably, aerosol generation was highly sensitive to the type of sweetener used within the typical range of food applications. Beverages containing natural sugars (e.g., sucrose, fructose) produced significantly more and larger droplets than those with artificial sweeteners or stevia. This was likely due to the combined effects of slightly increased viscosity, reduced surface tension, and elevated ionic strength. We emphasize that the in vitro droplet-impact assays provide an accessible, conservative model for probing formulation effects, whereas actual bubble-bursting in carbonated beverages is more complex. Overall, these findings provided a quantitative understanding of the role of aerosol droplets in carbonated sweet beverages and underscore the critical influence of sweetener type on aerosol-mediated flavor release.