How sweetener type and aroma concentration shape aroma release and flavour perception in sugar-free chewing gum

Sugar-free chewing gums (SFG) rely on added flavourings and sweeteners to compensate for the absence of sucrose. However, the interplay between aroma concentration, sweetener release, and flavour perception remains poorly understood. This study investigated how these factors shape in vivo aroma release and flavour perception during SFG consumption. In Experiment 1, model SFGs were prepared with five concentrations (0.2–1.0%) of a tutti-frutti aroma mixture. In vivo volatile release was monitored by nose-space Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS), while a trained panel assessed aroma and sweetness perception using discrete Time-Intensity (DTI). Higher aroma concentrations significantly increased both in-nose release and aroma perception but did not alter sweetness perception. Aroma perception peaked during the first 2 min of chewing and then declined faster than instrumental release. In Experiment 2, the release of five sweeteners (sorbitol, mannitol, xylitol, maltitol, and aspartame) was quantified in vitro using a chewing simulator and ultra-high-performance liquid chromatography (UHPLC-HRMS). A biphasic release profile was observed: an initial burst (0–120 s) followed by a sustained release phase. Xylitol showed the highest relative release, sorbitol the greatest absolute amount and aspartame was released most slowly. The results show that in this case aroma concentration enhances volatile release but not sweetness perception, and that sweetener release dynamics only partially explain flavour perception. The combined use of PTR-ToF-MS, sensory analysis, and UHPLC-HRMS provides a comprehensive framework to study flavour dynamics in SFG and can guide formulation strategies for improved consumer experience. • Aroma concentration increased in-nose aroma release but not perceived sweetness. • Aroma perception rose with concentration but was shaped by perceptual thresholds. • Esters showed burst release, while vanillin displayed sustained release. • Sweetener release followed biphasic kinetics with compound-specific patterns. • Combined nose-space PTR-MS, sensory dTI, and UHPLC-MS revealed flavour dynamics.