Retronasal aroma simulator

This unit discusses the use and design of the two mouth simulators, the retronasal aroma simulator (RAS) and the model mouth, that have successfully been verified to produce an effluent with volatile ratios similar to that found in human exhaled breath during eating. Though at a glance the apparatuses seem very different, they produce relatively similar effluents. Of obvious notability is the difference in the size of the reservoir the RAS reservoir is 1 liter and the model mouth reservoir is 70 ml. When determining which apparatus to use, carefully consider concentration needs, absorption characteristics of compounds, and shear resistance of the food. 

Retronasal aroma simulator (RAS, available from DATU) with temperature-controlled water jacket or water bath... 

Deibler, K.D. 2001. Measuring the effects of food composition on flavor release using the retronasal aroma simulator and solid phase microextraction. Ph.D. dissertation, pp. 131. Cornell University, Ithaca, New York. 

Deibler, K.D., Acree, T.E., Lavin, E.H., Taylor, A.J., and Linforth, R.S.T. 2000. Flavor release measurements with retronasal aroma simulator. In 6th Wartburg Aroma Symposium, April 11, 2000, Eisenach, Germany. 

Roberts, D.D. 1996. Flavor release analysis using a retronasal aroma simulator (olfactory). Cornell University, New York. 

Roberts, D.D. and Acree, T.E. 1996a. Effects of heating and cream addition on fresh raspberry aroma using a retronasal aroma simulator and gas chromatography olfactometry. 7. Agric. Food Chem. 44 3919-3925. 

Analytical methods involving exhaustive extraction of flavor compounds (i.e., liquid/liquid extraction, dynamic headspace) do not take these matrix effects into account. However, new instrumentation and methodologies are yielding improved information on the mechanisms involved in flavor/matrix interactions and the effects on flavor perception. For example, spectroscopic techniques, such as nuclear magnetic resonance (NMR), can provide information on complex formation as a function of chemical environment and have been used to study both intra- and intermolecular interactions in model systems [28,31]. In addition, NMR techniques, initially developed to study ligand binding for biological and pharmaceutical applications, were applied in 2002 to model food systems to screen flavor mixtures and identify those compounds that will bind to macromolecules such as proteins and tannins [32]. Flavor release in the mouth can be simulated with analytical tools such as the retronasal aroma simulator (RAS) developed by Roberts and Acree [33]. These release cells can provide... 

In order to incorporate the described effects of the oral physiological parameters on the mechanisms governing the release of aroma compounds from food systems to existing in vitro analysis, a number of devices (mouth simulators) have been developed [12,32-38]. Additionally, these devices were also developed to relate the aroma release more elosely to the aroma profile reaching the olfactory receptors in vivo. Both the retronasal aroma simulator (RAS) and the model mouth system have been shown to differ significantly from both purge and trap and conventional headspace analysis [37,39-40]. Furthermore, verification of both the RAS and model mouth system with in vivo measurements has been undertaken [39,41]. 

Parameter Model mouth Retronasal aroma simulator... 

Figure 4 Retronasal aroma simulator. Effect of increasing saliva volume on the release of five volatile compoxmds at 300 rpm sunflower oil-in-starch emulsion. Mean values with different symbols (a-d) indicate a significant effect (P < 0.05) of saliva volume.

Roberts, D.D., T.E. Acree, Simulation of retronasal aroma using a modified headspace technique investigating the effects of saliva, temperature, shearing, and oil on fiavor release, J. Agric. Food Chem., 43(8), p. 2179, 1995. 

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