Taste psychophysics of bitter phytochemicals

描述(申请人提供)：富含蔬菜和水果的饮食可降低罹患癌症和其他系统性疾病的风险。酚类、类黄酮类、异黄酮类、萜类和硫代葡萄糖苷等植物化学物质具有抗氧化和抗癌活性，并显示出广泛的肿瘤阻断活性。这些植物化学物质中的许多都有苦味，这可能会导致避免食用含有它们的食物。口味也是食物选择中最重要的因素；它比营养价值、成本、便利性和体重控制更重要。然而，感知一些苦味物质的能力是由基因调节的；大约25%的人无法感知6-丙基硫氧嘧啶(道具)的苦味，50%的人可以品尝到它，25%的人被认为是超级味觉者。研究表明，品尝道具的人对苦蔬菜和沙拉蔬菜的接受度较低。因此，品尝道具的人可能不太可能采用强调食用苦味蔬菜的防癌饮食。对植物化学物质柚皮苷、柠檬苦素、栎素、锡尼格林和染料木素的阈值和阈值以上的苦味知之甚少。这项研究的目的是确定这些苦涩的植物化学物质是如何被(超级)品尝者和非品尝者感知的。通过拟议的实验获得的知识将深入了解遗传味觉敏感度在食物偏好和食物选择中所起的作用。五种植物化学物质以及氯化钠和丙酮的检测阈值将用最大似然自适应阶梯法确定。所有七种物质的心理物理功能都将用标记的量度来测量。受试者还将对这七种物质的五种浓度中的每一种进行评级。此外，还将收集食物偏好数据。预计这项研究将为每种植物化学物质带来安全和可用的刺激范围，以便在未来获得儿童的数据。

DESCRIPTION (provided by applicant): Diets rich in vegetables and fruit lower the risk of cancer and other systemic diseases. Phytochemicals such as phenols, flavonoids, isoflavones, terpenes and glucosinolates have anti-oxidant and anti-carcinogenic properties and demonstrate a wide spectrum of tumor-blocking activities. Many of these phytochemicals have a bitter taste, which could lead to avoidance of the foods containing them. Taste also is the most important factor in food choice; it is more important than nutritional value, cost, convenience and weight control. The ability, however, to perceive some bitter substances is genetically mediated; about 25% of the population is unable to perceive the bitterness of 6-n-propylthiouracil (PROP), 50% can taste it, and 25% are considered supertasters. It has been shown that PROP tasters have a lower acceptance of bitter vegetables and salad greens. PROP tasters might therefore be less likely to adopt a diet for cancer prevention that emphasizes consumption of bitter vegetables. Very little is known about threshold and suprathreshold bitter perception of the phytochemicals naringin, limonin, quercetin, sinigrin and genistein. The purpose of this study is to determine how these bitter phytochemicals are perceived by (super) tasters and non-tasters of PROP. The knowledge gained through the proposed experiments will provide insight into the role genetic taste sensitivity plays in food preference and food choice. Detection thresholds for the five phytochemicals and sodium chloride and PROP will be determined with a maximum likelihood adaptive staircase method. Psychophysical functions for all seven substances will be measured with the Labeled Magnitude Scale. Subjects will also rate how much they like each of five concentrations of the seven substances. Furthermore, food preference data will be gathered. It is anticipated that this study will result in safe and usable ranges of stimulation for each of the phytochemicals, so that in the future data from children can be obtained.