Background

Temporal dynamics may importantly modulate sensory perception, including taste. For example, enhanced perceived taste intensity is often observed when tastant concentration is fluctuating in pulses. The perceived intensity is higher than that of the solutions with a same averaged, but constant concentrations. Meanwhile, taste intensity often decreases with increase of tastant viscosity, despite no changes to the stimuli concentration. The mechanisms to these phenomena are not well understood, in part due to the complicated transport process of tastant through papillae, taste pores, etc. to reach the taste receptors, a cascade of events that are difficult to quantify.

Method

We computationally modeled the human tongue surface as a porous micro-fiber medium, extending a previous study and exposed it to pulsatile tastant solution (0.2 and 0.4Hz) with various added viscosity (~0.0011–~0.09 Pa⋅s).

Results

Our simulation revealed that the stimuli concentration within the papillae structure increase with pulsed stimulation, especially those with a longer period (16% increase at 0.4Hz and 23% at 0.2Hz compared to continuous stimuli) and decrease (−6%) with added viscosity. The trend matched well with measured taste perception to sucrose added apple juice in the literature (R² > 0.97 for both low and high viscosity stimuli series). Decreased diffusivity due to the increase in viscosity, however, was not a major factor underlying this process.

Conclusion

This study re-affirms the validity and accuracy of modeling human tongue surface as a porous medium to investigate taste stimuli transport processes and such peripheral transport dynamics may have significant effects on taste perception.

中文翻译：

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脉动率和粘度对味觉的影响——多孔介质模型在人舌表面的应用

背景

时间动态可能重要地调节感官知觉，包括味觉。例如，当促味剂浓度在脉冲中波动时，通常会观察到增强的感知味觉强度。感知强度高于具有相同平均但恒定浓度的溶液。同时，尽管刺激浓度没有变化，但味道强度通常会随着促味剂粘度的增加而降低。这些现象的机制尚不清楚，部分原因是味觉通过乳头、味孔等到达味觉感受器的复杂运输过程，一系列难以量化的事件。

方法

我们通过计算将人类舌头表面建模为多孔微纤维介质，扩展了先前的研究并将其暴露于具有各种附加粘度（~0.0011–~0.09 Pa·s）的脉动促味剂溶液（0.2 和 0.4Hz）中。

结果

我们的模拟表明，乳头结构内的刺激浓度随着脉冲刺激而增加，特别是那些具有较长周期的刺激浓度（与连续刺激相比，在 0.4Hz 时增加 16%，在 0.2Hz 时增加 23%），并随着粘度的增加而减少（-6%） . 该趋势与文献中对添加蔗糖的苹果汁测量的味觉非常匹配（对于低粘度和高粘度刺激系列，R ²  > 0.97）。然而，由于粘度增加而导致的扩散率降低并不是该过程的主要因素。

结论

本研究再次证实了将人类舌头表面建模为多孔介质来研究味觉刺激传输过程的有效性和准确性，并且这种外围传输动力学可能对味觉产生显着影响。