Evidence for human orosensory (taste?) sensitivity to free fatty acids
Evidence for human orosensory (taste?) sensitivity to free fatty acids
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DOI：
10.1093/chemse/bjm007
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发表时间：
2007-06-01
期刊：
影响因子：
3.5
通讯作者：
Mattes, Richard D.
中科院分区：
文献类型：
--
作者：
Chale-Rush, Angela;Burgess, John R.;Mattes, Richard D.
越来越多的证据表明，膳食脂肪酸(FAs)可能在口腔中被感知。然而，有效的线索尚未被描述。特别是，来自其他感官线索的影响阻碍了对独立味觉贡献的识别。实验1研究了减少FA氧化产物形成和改善水/脂质乳液均匀性的技术，这些技术将在实验2中用作刺激，这是一项确定人类FA检测阈值的心理物理学研究。在聚丙烯实验装置中对冷冻样品进行超声处理，加入0.01%乙二胺四乙酸和二钠钙盐，得到了未氧化亚油酸和油酸脂肪酸的均质乳状体。分光光度分析显示在24小时内没有氧化产物形成。与这些技术相结合，一种掩蔽方法被用来最小化其他来自亚油酸、油酸和硬脂酸FAs的感官信号。分别用5%矿物油（w/v）和5%金合木胶（w/v）配制浓度为0.00028% ~ 5% （w/v）的混合物，以掩盖其润滑性和粘度效应。测试是在红灯下进行的，鼻子被挡住，以消除视觉和嗅觉线索。在重新测量亚油酸检测阈值之前，使用含有20 ppm辣椒素的口腔冲洗液使参与者对选定的刺激效应脱敏。为了确定有效刺激物是否为氧化产物，在测试刺激物中加入氧化亚油酸。检测阈值是通过三种选择，强迫选择浓度上升表示程序获得的。亚油酸脱敏前的平均检测阈值为0.034 +/- 0.008%，亚油酸脱敏后的平均检测阈值为0.032 +/- 0.007%，油酸为0.022 +/- 0.003%，硬脂酸为0.032 +/- 0.005%，氧化亚油酸为0.025 +/- 0.005%。结果表明，亚油酸、油酸、硬脂酸和氧化亚油酸可以在人的口腔中检测到，而嗅觉、辣椒素和粘度评估触觉系统的输入最小。
Accumulating evidence suggests dietary fatty acids (FAs) may be sensed in the oral cavity. However, the effective cues have not been characterized. In particular, influences from other sensory cues have hampered identification of an independent gustatory contribution. Experiment 1 examined techniques to minimize the formation of FA oxidation products and improve the homogeneity of water/lipid emulsions to be used as stimuli in Experiment 2, a psychophysical study to determine FA detection thresholds in humans. Through sonication of chilled samples held in polypropylene labware and the addition of 0.01% ethylenediaminetetraacetic acid, calcium disodium salt, homogenous emulsions of unoxidized linoleic and oleic FAs were obtained. Spectrophotometric analysis revealed no oxidation product formation over a 24-h period. Coupled with these techniques, a masking approach was used to minimize other sensory cues imparted from linoleic, oleic, and stearic FAs. Concentration ranges from 0.00028% to 5% (w/v) were prepared in mixtures with 5% mineral oil (w/v) and 5% gum acacia (w/v) to mask lubricity and viscosity effects, respectively. Testing was conducted under red light with nares blocked to eliminate visual and olfactory cues. Oral rinses with 20 ppm capsaicin were administered to desensitize participants to selected irritation effects prior to remeasuring linoleic acid detection thresholds. To determine if the effective stimulus was an oxidation product, oxidized linoleic acid was included among the test stimuli. Detection thresholds were obtained using a 3-alternative, forced-choice ascending-concentration presentation procedure. The mean detection threshold for linoleic acid pre-desensitization was 0.034 +/- 0.008%, for linoleic acid post-desensitization was 0.032 +/- 0.007%, for oleic 0.022 +/- 0.003%, for stearic 0.032 +/- 0.005%, and oxidized linoleic 0.025 +/- 0.005%. The results suggest that linoleic, oleic, stearic, and oxidized linoleic acids are detectable in the oral cavity of humans with minimal input from the olfactory, capsaicin, and viscosity-assessing tactile systems.