1046例汉族青年苯硫脲尝味能力的测定

苯硫脲味盲属隐性遗传,基因型为tt。苯硫脲味盲在各种族人群所占的比例不同,我们用阈值法测定1046名安徽汉族青年的味盲率为7.65％,尝味者的平均阈值为8.95±1.73。男女性间的味盲率及尝味者平均阈值在统计学上都无显著性差异。另外,我们研究的结果与已报道的资料相比较表明,在相似年龄组的不同汉族人群间有PTC尝味多态性。     

河北省汉族人苯硫脲尝味能力测定与分析

测定了１００８名汉族人的苯硫脲尝味阈值。从中检出味盲者７５人，味盲率７．４４％，受试人群无显著性别差异。尝味者９３３人，平均尝味阈值为１０．３４±１．４９，在儿童中无性别差异，但在成人中女性明显低于男性。儿童的味盲率和平均尝味阈值的低于成人。     

内蒙古地区蒙古族和汉族苯硫脲尝味能力的测定

本文采用Harris和Kalmus改良阈值法测定了内蒙古地区2034例(蒙古族998例,汉族1036例)苯硫脲尝味阈值。以4号液为味盲界限。蒙古族中味盲者116人(11.62%),尝味者882人,平均尝味阈值9.29±1.44;汉族中味盲者104人(10.04%),尝味者932人,平均尝味阈值9.33±1.44.味盲率在蒙、汉民族间、男女性别间、内蒙东、西部地区间均无显著性差异。苯硫脲平均尝味阈值在蒙、汉民族间也不存在显著差异,但同一民族的地区性差异显著,男女性差亦极其显著,女性比男性大约低0.48～0.51。     

甘肃汉族人群苯硫脲尝味能力调查报告

<正> 苯硫脲(Pheny lthiocartbamide或pheny l thiourea简称P·T·C)是由尿素合成的白色结晶化合物,含有呈苦味的硫代酰胺基结构。1931年Fox作P·T·c定量分析时,一起工作的Noller说:“房子太苦”而自己却无此感觉,因而发现人群在尝味时,可分为能尝出苦味的尝味者和尝不出苦味的味盲者两类人群。1934年Parr发现不同种     

贵州苗族布依族汉族PTC尝味能力的调查

用阈值法对贵州长顺县的苗族、布依族、汉族的苯硫脲（ＰＴＣ）尝味能力进行了调查，共检测了２０４７人。结果表明：不同民族ＰＴＣ尝味阈值的差异高度显著（Ｐ＜０．０１），不同民族间的味盲率亦有显著性的差异（Ｐ＜０．０５）。三个民族总计中，男女尝味阈值的差异高度显著（Ｐ＜０．０１），味盲率呈显著性差异（Ｐ＜０．０５）；苗族、布依族和汉族中，男女尝味阈值均有高度显著性差异（Ｐ＜０．０１），苗族、布依族的男女性别的味盲率间均无显著性差异（Ｐ＞０．０５），汉族的男女味盲率间差异显著（Ｐ＜０．０５）．三个民族中，味盲基因（ｔ）频率以汉族为最高（ｔ＝０．２２４２）。     

体育系学生苯硫脲尝味能力与血型的研究

对体育系１４０名学生苯硫脲尝味能力及血型的研究发现：（１）体育系学生的味盲率为２２．９％，显著高于一般人群．（２）Ｏ型血者在排球专项中占５７．９％，显著高于其他血型的比率．（３）各种血型中以Ｏ型血者味盲率最高，为２５．６％．     

体育系学生苯硫脲尝味能力与血型的研究

对体育系１４０名学生苯硫脲尝味能力及血型的研究发现：（１）体育系学生的味盲率为２２．９％，显著高于一般人群。（２）Ｏ型血者在排球专项中占５７．９％，显著高于其他血型的比率。（３）各种血型中以Ｏ型血者味盲率最高，为２５．６％。     

新疆不同地区维吾尔族苯硫脲尝味遗传多态性研究

采用改进阈值法,测试统计分析了新疆维吾尔自治区内不同地区的7 469例(男性3 831例、女性3 638例)维吾尔族中学生和大学生(12~25岁)苯硫脲尝味能力的阈值分布、味盲率、基因型频率和基因频率.结果显示维吾尔族苯硫脲尝味能力的阈值分布和味盲率具有本民族的自身特点.在新疆维吾尔自治区内,不同地区的维吾尔族苯硫脲尝味味盲率不同,并具有极显著性差异(P0.01),从东部(哈密地区)到西部(喀什地区),苯硫脲味盲率逐渐增加,平均味盲率为24.13%,介于欧罗巴人种和其他有色人种之间,该现象与人类学关于现代维吾尔族的族源、人种构成及演化过程的"合流说"相吻合.     

苯硫脲味盲基因型与蔬菜嗜好性关系分析

目的研究人味盲基因型与人对蔬菜的嗜好性关系．方法采用阈值法测定269人的味觉基因型，问卷调查他们对蔬菜的嗜好性．结果经X^2检测发现，不同的味觉基因型个体对蔬菜有不同的偏好．结论人的PTC味盲基因型明显影响人对甘蓝苦味、菠菜涩味的敏感程度，这对于指导普通人群的饮食具有一定的参考价值．     

食品的色味香

二、食品的味1.味觉(Sense of laste)在人的感觉中,味觉和嗅觉是由化学物质所引起的,故被称为化学感觉(chemicalsenses)。物质的化学构造与味和香气之间有着极密切的关系。味是由分布在舌和上腭上的味蕾来感受的。味蕾由十多个味细胞组成;在味细胞的前端有味觉感受器。在味觉现象中包含着复杂的过程:味觉刺激是味物质被这些味觉感受器的表面吸附而引起的,生成的刺激讯息变为神经冲动讯息,然后传达至脑。在味道中,甜味、酸味、咸味和苦味是四种基本的味道。在日本除此而外,加“鲜”味     

Independent evolution of bitter-taste sensitivity in humans and chimpanzees

It was reported over 65 years ago that chimpanzees, like humans, vary in taste sensitivity to the bitter compound phenylthiocarbamide (PTC). This was suggested to be the result of a shared balanced polymorphism, defining the first, and now classic, example of the effects of balancing selection in great apes. In humans, variable PTC sensitivity is largely controlled by the segregation of two common alleles at the TAS2R38 locus, which encode receptor variants with different ligand affinities. Here we show that PTC taste sensitivity in chimpanzees is also controlled by two common alleles of TAS2R38; however, neither of these alleles is shared with humans. Instead, a mutation of the initiation codon results in the use of an alternative downstream start codon and production of a truncated receptor variant that fails to respond to PTC in vitro. Association testing of PTC sensitivity in a cohort of captive chimpanzees confirmed that chimpanzee TAS2R38 genotype accurately predicts taster status in vivo. Therefore, although Fisher et al.'s observations were accurate, their explanation was wrong. Humans and chimpanzees share variable taste sensitivity to bitter compounds mediated by PTC receptor variants, but the molecular basis of this variation has arisen twice, independently, in the two species.     

The receptors and coding logic for bitter taste

The sense of taste provides animals with valuable information about the nature and quality of food. Bitter taste detection functions as an important sensory input to warn against the ingestion of toxic and noxious substances. T2Rs are a family of approximately 30 highly divergent G-protein-coupled receptors (GPCRs) that are selectively expressed in the tongue and palate epithelium and are implicated in bitter taste sensing. Here we demonstrate, using a combination of genetic, behavioural and physiological studies, that T2R receptors are necessary and sufficient for the detection and perception of bitter compounds, and show that differences in T2Rs between species (human and mouse) can determine the selectivity of bitter taste responses. In addition, we show that mice engineered to express a bitter taste receptor in 'sweet cells' become strongly attracted to its cognate bitter tastants, whereas expression of the same receptor (or even a novel GPCR) in T2R-expressing cells resulted in mice that are averse to the respective compounds. Together these results illustrate the fundamental principle of bitter taste coding at the periphery: dedicated cells act as broadly tuned bitter sensors that are wired to mediate behavioural aversion.     

味觉传感器的研究──计算机对一个新的液膜体系中酸、甜、苦、咸物质的定性识别

本文用十六烷基三甲基溴化铵十乙醇／含苦味酸的二氯甲烷／蔗糖水溶液为研究体系，在油水界面建立可兴奋性人工膜，观察到甜、酸、苦、咸物质均能对该体系振荡波形有影响。采用模糊数学的方法，用计算机对有味物质实现定性识别，取得了满意的结果。并解释了该味觉电化学传感器产生电位振荡响应的机理和利用模糊数学进行模式识别的规则。     

催陈酒的氨基酸分析

对新生产的未经催陈处理的酒,自然陈酿3年的出厂成品酒、经催陈处理的0 33t中试酒及4 5t生产性实验的酒样,测定其17种游离氨基酸的含量,并对氨基酸含量的增减及味感进行分类,结果表明,甜味氨基酸增加较多,苦味氨基酸减少较多,结果使酒的苦涩味减少,口感更加舒适、协调,达到了陈化的目的.     

催陈酒的氨基酸分析

对新生产的未经催陈处理的酒,自然陈酿3年的出厂成品酒、经催陈处理的0.33t中试酒及4.5t生产性实验的酒样,测定其17种游离氨基酸的含量,并对氨基酸含量的增减及味感进行分类,结果表明,甜味氨基酸增加较多,苦味氨基酸减少较多,结果使酒的苦涩味减少,口感更加舒适、协调,达到了陈化的目的.     

热风微波联合干燥过程中南美白对虾滋味物质变化研究

为研究热风微波联合干燥过程中南美白对虾滋味物质的变化,测定了其呈味核苷酸与游离氨基酸含量,同时根据干燥过程中虾肉水分含量计算两者的干基含量变化,并计算虾肉味精当量。研究结果表明:虾肉干燥过程中,呈味核苷酸中肌苷酸含量最高,干制虾肉肌苷酸含量为405.96mg/100g,且始终高于阈值,对干制虾肉的鲜味形成有显著贡献;相比鲜样,干制南美白对虾中肌苷酸与单磷酸腺苷干基含量均显著下降;在虾肉中谷氨酸对鲜味形成有显著贡献,甘氨酸、丙氨酸与精氨酸对甜味形成有贡献,苯丙氨酸、赖氨酸与组氨酸能产生苦味;而在干燥过程中鲜、甜味氨基酸相对含量不断上升,分别从3.77%和17.03%上升到4.29%和35.84%;游离氨基酸总干基含量始终下降,但甘氨酸、丙氨酸、精氨酸与脯氨酸4种可以形成良好滋味的游离氨基酸干基含量上升;虾肉中肌原纤维蛋白与肌浆蛋白的干基含量均不断下降,部分分解为游离氨基酸;虾肉味精当量整体呈显著上升趋势,但在微波干燥初期(前40s)显著下降,干制南美白对虾味精当量为3.50g/100g,远高于鲜虾(0.53g/100g),且虾肉味精当量始终远高于阈值。研究结果表明,由热风微波联合干燥引起的水分挥发与物质变化能够促进南美白对虾滋味形成。     

A family of candidate taste receptors in human and mouse

The gustatory system of mammals can sense four basic taste qualities, bitter, sweet, salty and sour, as well as umami, the taste of glutamate. Previous studies suggested that the detection of bitter and sweet tastants by taste receptor cells in the mouth is likely to involve G-protein-coupled receptors. Although two putative G-protein-coupled bitter/sweet taste receptors have been identified, the chemical diversity of bitter and sweet compounds leads one to expect that there is a larger number of different receptors. Here we report the identification of a family of candidate taste receptors (the TRBs) that are members of the G-protein-coupled receptor superfamily and that are specifically expressed by taste receptor cells. A cluster of genes encoding human TRBs is located adjacent to a Prp gene locus, which in mouse is tightly linked to the SOA genetic locus that is involved in detecting the bitter compound sucrose octaacetate. Another TRB gene is found on a human contig assigned to chromosome 5p15, the location of a genetic locus (PROP) that controls the detection of the bitter compound 6-n-propyl-2-thiouracil in humans.     

The cells and logic for mammalian sour taste detection

Mammals taste many compounds yet use a sensory palette consisting of only five basic taste modalities: sweet, bitter, sour, salty and umami (the taste of monosodium glutamate). Although this repertoire may seem modest, it provides animals with critical information about the nature and quality of food. Sour taste detection functions as an important sensory input to warn against the ingestion of acidic (for example, spoiled or unripe) food sources. We have used a combination of bioinformatics, genetic and functional studies to identify PKD2L1, a polycystic-kidney-disease-like ion channel, as a candidate mammalian sour taste sensor. In the tongue, PKD2L1 is expressed in a subset of taste receptor cells distinct from those responsible for sweet, bitter and umami taste. To examine the role of PKD2L1-expressing taste cells in vivo, we engineered mice with targeted genetic ablations of selected populations of taste receptor cells. Animals lacking PKD2L1-expressing cells are completely devoid of taste responses to sour stimuli. Notably, responses to all other tastants remained unaffected, proving that the segregation of taste qualities even extends to ionic stimuli. Our results now establish independent cellular substrates for four of the five basic taste modalities, and support a comprehensive labelled-line mode of taste coding at the periphery. Notably, PKD2L1 is also expressed in specific neurons surrounding the central canal of the spinal cord. Here we demonstrate that these PKD2L1-expressing neurons send projections to the central canal, and selectively trigger action potentials in response to decreases in extracellular pH. We propose that these cells correspond to the long-sought components of the cerebrospinal fluid chemosensory system. Taken together, our results suggest a common basis for acid sensing in disparate physiological settings.