Real-Time Release of Volatile and Non-Volatile Components from Chewing Gum Using a Mechanical Chewing Device

To date, the majority of research on chewing gum has been conducted using human subjects in conjunction with time-intensity sensory analysis and/or real-time mass spectrometry techniques (proton transfer reaction mass spectrometry [PTR-MS] or atmospheric pressure chemical ionization [API-MS]). The disadvantages of human subjects include their tremendous variability (salivary flow rate, masticatory force, mouth volume, mastication rate, respiration rate and others), low throughput of samples, and necessary training and compensation. For these reasons, it is desirable to fabricate a chewing device to simulate human mastication. Using this device, formulation and ingredient effects could be elucidated without convolution by inter-individual differences. The trade-off, however, is a lack of end-user perception, a potentially large capital investment, and difficulty replicating the conditions associated with human mastication.;In the work presented herein, we have developed such a chewing device to be used as a screening tool for ingredients and formulation effects in chewing gum. The device simplifies the chewing process so a more basic understanding of the release of volatile and non-volatile components from chewing gum can be achieved.;Following the construction of the chewing device, suitable methodology was developed to examine the release of volatile aroma compounds into the air (using PTR-MS or API-MS). Aroma compounds extracted in the simulated saliva were evaluated using GC-FID. Non-volatile compounds (polyols and high potency sweeteners) extracted into simulated saliva were measured using HPLC-MS and UPLC-MS.;Conducting a mass balance of chewing gum components validated the device and methodology. Analysis of chewing gum after simulated mastication revealed that a large portion of the aroma compounds remained in the bolus after 21 min of simulated mastication; only a small portion were found in the air and simulated saliva; the amount depended on the properties of the aroma compound. The water-soluble compounds, however, were almost entirely depleted from the chewing gum after 21 min.;In the second study, the chewing device was used to evaluate ingredients designed to delay the release of acesulfame-K (Ace-K), a high potency sweetener commonly used in chewing gum, from chewing gum during mastication. A response surface experimental design was used to optimize the entrapment of Ace-K in polyvinyl acetate (PVA). Three parameters were examined (particle size of Ace-K, total particle size, and core to matrix ratio) at three levels. Embodiments were incorporated into chewing gum containing no high-potency sweetener. Release was examined using the chewing device connected to a fraction collector sampling at 1 min intervals. Ace-K concentrations (mg/ml) were evaluated using UPLC-MS. Statistical analysis revealed the optimum conditions for delayed release (from 11-21 min) to be smaller Ace-K particles with larger total particle size.;The third study examined how differences in gum hardness affected the release of volatile aroma compounds and Ace-K. Three chewing gum formulations contained different levels of glycerin (3%, 6% or 9%). Static headspace was used as a measure of the effect of the matrix on volatility. Samples were masticated in the chewing device and the release of volatile aroma compounds was measured using an API-MS. Ace-K release was quantified at 1 min intervals using UPLC-MS. There were no significant differences in maximum intensity between the three chewing gums for the three volatile compounds (ethyl butyrate, isoamyl acetate, and limonene). Vapor pressure also was not significantly different between the three samples. These results potentially indicate that differences in perception between gums of differing textures are due to consumer perception and/or mastication rate and not differences in flavor release caused by the matrix or resistance to mass transfer.