Viton F.1, Pollien P.1 And Le Révérend B.1
1 Food Consumer Interaction, Nestlé Research Center, Lausanne, Switzerland E-mail:
In this work we quantify how differences in the drinking habits between different types of coffee consumers modulate aroma release. Aroma is transported from the coffee liquid and crema [1] matrices to the headspace and the nasal cavity by diffusion and convection processes, which have very different characteristic times.
To maximize the headspace concentration, it is important to maximize the effect of convection over diffusion within the liquid phase as the latter is the slowest. In addition the mass transfer coefficient at the coffee/headspace interface, relevant to the diffusion process is also influenced by the liquid mixing efficiency. It is not possible to follow the pathways of the aroma molecules during the release. As an approximation, we link tongue motion and in mouth bubbling by aspiration (which are respectively modulating convection and interfacial diffusion) visualization and aroma release by coupling two relevant measurement techniques [2]. Time resolved ultrasound visualization of the tongue and PTR- TOF-MS are coupled to obtain a time resolution of 20 ms allowing describing the influence of oral processing on aroma release with great temporal definition.
We will present those results which allow understanding if acuity in coffee tasting is effectively due to an improved efficiency in releasing aroma, as recently demonstrated for tastants [3], from the drink or to other factors such as phenotypic differences of the aroma sensing physiology and extensive sensory training.
References
[1] Barron D. et al. Impact of crema on the aroma release and the in-mouth sensory perception of espresso coffee, Food Funct., 2012, 3, 923-930
[2] Viton F. et al., Coupling of in-mouth physical phenomena with Nosespace analysis, a milestone towards understanding aroma release and perception from liquid matrices, ACS National Meeting, 2013
[3] Le Révérend B. et al. Modelling the human response to saltiness, Food Funct., 2013, DOI: 10.1039/C3FO30106K
