Division of Human Nutrition and Health, Wageningen University, P.O. Box 17, 6700 AA Wageningen, the Netherlands.
Sensory Evaluation Center, Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, 220 Food Science Building, University Park, PA 16802, USA.
Food Res Int. 2021 Nov;149:110702. doi: 10.1016/j.foodres.2021.110702. Epub 2021 Sep 15.
The trigeminal nerve transduces both chemical irritation and textural sensations suggesting that perception in one may influence perception in the other. Little is known about how the oral burn of capsaicin may affect texture sensitivity. The aim of this study was to determine the effect of burning sensations on thickness discrimination thresholds in liquid foods assessed by consumers who vary in habitual spicy food intake. Forty-seven Caucasian participants (31 females and 16 males; mean age: 25.0 ± 5.7 yrs; mean BMI: 21.5 ± 2.6 kg/m) were recruited in the Netherlands. Chili pepper intake frequency and preference for chili peppers and spicy foods were assessed using questionnaires. Perceived burn and disliking/liking of bouillon soups thickened with xanthan gum (concentrations ranging from 0.06 to 0.21 g/mL; viscosity at 50 s (η) ranging from 11 to 48 mPas) containing varying amounts of capsaicin (0, 1, or 10 ppm) were determined using generalized scales (gLMS and gDOL). Estimates of thickness discrimination thresholds were determined using the 2-Alternative Forced Choice ascending staircase method. Capsaicin was applied in two ways: (i) capsaicin was added directly to the soups or (ii) a pre-rinse of a capsaicin solution was held in mouth before evaluating soups without capsaicin. As expected, frequent chili pepper consumers reported significantly lower burn intensity and higher hedonic ratings compared to infrequent consumers. Thickness discrimination thresholds (i.e., BET expressed as Δη) increased significantly from 11.3 mPas at 0 ppm to 16.1 mPas at 1 ppm (42% increase) to 21.4 mPas at 10 ppm capsaicin (89% increase) on average across all participants. Similar modification of thickness discrimination thresholds were observed regardless of whether capsaicin was added to the soup or was applied as a pre-rinse. No significant differences in thickness discrimination thresholds were observed between infrequent and frequent chili consumers. We conclude that oral burn caused by capsaicin affects thickness discrimination independently of reported chili pepper intake. Also, we suggest the ability of capsaicin to alter thickness discrimination may be due to increased neural noise, attentional effects or cross-modal interactions.
三叉神经既能传递化学刺激，也能传递质地感觉，这表明一种感觉的感知可能会影响另一种感觉的感知。目前对于辣椒素引起的口腔烧灼感如何影响质地敏感性知之甚少。本研究旨在确定不同习惯性食用辛辣食物的消费者对液体食品的厚度辨别阈值的影响。47 名白种人参与者（31 名女性和 16 名男性；平均年龄：25.0±5.7 岁；平均 BMI：21.5±2.6kg/m）在荷兰招募。使用问卷评估辣椒摄入量频率、对辣椒和辛辣食物的偏好。通过广义量表（gLMS 和 gDOL）测定含不同浓度（0、1 或 10ppm）辣椒素的黄原胶增稠肉汤（浓度范围为 0.06 至 0.21g/mL；50 秒时的粘度（η）范围为 11 至 48mPas）的感知烧灼感和不喜欢/喜欢程度。使用 2-交替强制选择上升阶梯法确定厚度辨别阈值的估计值。以两种方式应用辣椒素：（i）直接向汤中添加辣椒素或（ii）在评估不含辣椒素的汤之前，先在口中含一口辣椒素溶液。如预期的那样，经常食用辣椒的消费者报告的烧灼感强度明显低于不经常食用的消费者，愉悦感评分也更高。厚度辨别阈值（即 BET 表示为 Δη）平均从 0ppm 时的 11.3mPas 显著增加到 1ppm 时的 16.1mPas（增加 42%）和 10ppm 时的 21.4mPas（增加 89%）。无论辣椒素是添加到汤中还是作为预冲洗剂应用，都观察到了相似的厚度辨别阈值的改变。在不常食用和常食用辣椒的消费者之间，厚度辨别阈值没有显著差异。我们得出的结论是，辣椒素引起的口腔烧灼感会独立于报告的辣椒摄入量影响厚度辨别。此外，我们认为辣椒素改变厚度辨别能力可能是由于神经噪声增加、注意力效应或跨模态相互作用所致。
