Mouth simulators

Aroma compounds, see also Citrus Oils Flavor analysis GC analysis mouth simulators Ascorbic acid, 397... 

Headspace SPME is a solventless extraction method where a silica fiber coated with adsorbant or absorbant polymer material is exposed to a gas phase to extract analytes. The food of interest is placed in a closed or open container (such as a mouth simulator). After extraction, the fiber is desorbed in a GC injection port for separation and detection of the extracted analytes. 

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. 

Figure Gl.7.lisa comparison of chromatograms from a solid-phase microextraction (SPME) from a beverage in a sealed container and from the same beverage in a mouth simulator. This comparison demonstrates that a very different volatile ratio is produced from the same food under different sampling conditions. Due to these differences, it is important to use a sampling method that simulates mouth conditions when studying flavor compositions that produce a human perception. Most methods intended to increase headspace volatile concentration, such as adding salt for salting out, do not uniformly affect volatility. For some compounds,...

The model mouth and RAS are two examples of mouth simulators. A representative set of mouth simulators are compared in Table Gl.7.1. All account for temperature, breath flow, and mastication. Only the model mouth and the RAS allow for the evaluation of solid foods and have been compared directly to human breath. 

A mouth simulator is a valuable tool when determining what volatiles contribute to the flavor sensation during consumption of a food. This includes determining potency (e.g., Char-mAnalysis), intensity (e.g., OSME Acree and Barnard, 1994), contribution (e.g., omission tests), and effect of a compound on the flavor. Sample preparation with a mouth simulator gives a close representation of the human experience, without the expense and variability of using humans. The limitations of headspace sampling and detection sensitivity define the limits of the use of mouth simulators. 

KD Deibler, EH Lavin, RST Linforth, AJ Taylor, TE Acree. Verification of a mouth simulator by in vivo measurements. J Agric Food Chem 49 1388-1393, 2001. 

Effects of Oral Physiological Characteristics on the Release of Aroma Compounds from Oil-in-Water Emulsions Using Two Mouth Simulator Systems... 

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]. 

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