电子舌对不同类型酒味觉的辨识研究

为了研究电子舌对不同类型酒的识别能力。 将所有样品按照酒∶水=1∶2（V/V）进行稀释后,采用TS-5000Z味觉分析系统进行 检测,再对传感器信号进行主成分分析（PCA）、雷达图分析和稳定性分析。结果表明,主成分1（PC1）为苦味,贡献率为91.5%;主成分2（PC2）为酸味,贡献率为5.8%。 1#和4#样品味觉相近,分为一类;2#、3#和5#样品味觉相近,分为一类;6#、7#样品与其他样品的味觉都不 一样,各自单独分为一类。 2#样品酸味最强,涩味最弱;7#样品酸味最弱、涩味最强、苦味最强;4#样品苦味最弱。 可见电子舌能有效区 分不同类型酒的味感差别。     

利用电子舌分析热加工酸肉滋味特征

采用电子舌及多元统计方法分析4 种发酵酸肉经不同热处理后的滋味品质,通过主成分分析、判别分析及聚类分析对经不同热处理的酸肉进行差异性及聚类分析。结果表明：不同种类酸肉或经不同加热处理后酸肉的电子舌滋味强度存在显著差异（P＜0.05）,可通过判别分析、聚类分析将酸肉进行分类,聚类分析将苗族酸肉、小米酸肉及微波处理傣族酸肉聚为一类,蒸制、油炸、烤制傣族酸肉为一类,微波处理辣椒酸肉为一类,蒸制、油炸、烤制辣椒酸肉为一类;酸肉中酸、苦、涩、咸、鲜、甜6 种基本滋味均存在显著差异（P＜0.05）。     

An overview of binary taste–taste interactions

The human gustatory system is capable of identifying five major taste qualities: sweet, sour, bitter, salty and savory (umami), and perhaps several sub-qualities. This is a relatively small number of qualities given the vast number and structural diversity of chemical compounds that elicit taste. When we consume a food, our taste receptor cells are activated by numerous stimuli via several transduction pathways. An important food-related taste question which remains largely unanswered is: How do taste perceptions change when multiple taste stimuli are presented together in a food or beverage rather than when presented alone? The interactions among taste compounds is a large research area that has interested electrophysiologists, psychophysicists, biochemists, and food scientists alike. On a practical level, taste interactions are important in the development and modification of foods, beverages or oral care products. Is there enhancement or suppression of intensity when adding stimuli of the same or different qualities together? Relevant psychophysical literature on taste–taste interactions along with selected psychophysical theory is reviewed. We suggest that the position of the individual taste stimuli on the concentration-intensity psychophysical curve (expansive, linear, or compressive phase of the curve) predicts important interactions when reporting enhancement or suppression of taste mixtures.     

Tasting spoons: Assessing how the material of a spoon affects the taste of the food

This study investigated the effect that the taste of certain metals has on the perception of food. Four spoons plated with different metals (gold, copper, zinc, and stainless steel) were used to taste cream samples having different tastes: sweet, sour, bitter, salty, and plain. The results revealed that the zinc and copper spoons, in addition to transferring a somewhat metallic and bitter taste, enhanced to a greater or lesser extent, each cream’s dominant taste. Contrary to our expectations, the metallic taste of the copper and zinc spoons did not seem to affect the pleasantness of the samples significantly. These findings reveal that the effect that the metals from which cutlery can be made have on food perception differs from that found when the metal salts are added to the composition of the food itself.     

滋味物质间相互作用的研究进展

人类的味觉提供了有关食品质量及其组成的必要信息。人类可鉴别出食物的5 种基本味觉,即甜、咸、酸、苦和鲜味,但食物是多种滋味化合物组成的混合体系,因此滋味物质间相互作用是不可避免的。滋味物质间的相互作用发生在3 个层面,即化合物混合时的化学反应、一种物质对另一种物质滋味受体的影响、混合物质在大脑中的综合感知。其中研究较多的是滋味物质在第二层面上的相互作用。二元、三元及多元滋味物质之间的关系是复杂的：当滋味化合物低强度/浓度混合时呈现增强效应;中等强度/浓度往往呈现加和作用;高强度/浓度混合时常呈现抑制作用。另外,滋味感知受很多因素的影响,如温度、pH值、黏度、硬度、受试者生理状况等。滋味物质间相互作用的研究主要聚焦在饮料滋味改良、药品苦味掩盖和口腔护理产品开发等具有广阔研究前景。     

酸食的地域性研究—以贵州黔东南西江苗寨为例

为评价水族红酸汤的品质特征,以苗族红酸汤为参比,采用国标法、氨基酸分析法与顶空固相微萃取-气相色谱-质谱联用法（Headspace-Solid phase microextraction-gas chromatography mass spectrometry,HS-SPME-GC-MS）对苗族、水族红酸汤的理化成分、游离氨基酸及香气成分进行分析。结果表明,水族红酸汤的总酸、还原糖、脂肪和蛋白质等含量均高于苗族红酸汤;两种红酸汤中共检测出19种游离氨基酸,水族红酸汤中呈味氨基酸与总氨基酸含量是苗族红酸汤的2倍,其中丙氨酸和谷氨酸的滋味活度值（taste activity value,TAV）>1,是两种红酸汤的关键呈味氨基酸;在红酸汤中共检测出101种挥发性物质。利用正交偏最小二乘法（orthogonal least partial squares,OPLS-DA）的重要性变量投影（VIP）筛选出十六酸丙酯、4-乙基-2甲氧基苯酚、5-环己基-2戊酮、山梨酸等32个关键差异物。通过相对香气活性值（Relative odor activity value,ROAV）发现苗族红酸汤中酸味较水族红酸汤明显,水族红酸汤果香味特征较苗族红酸汤明显,两种红酸汤中脂香均由水杨酸甲酯提供,但主要呈酒香的挥发性物质不同,苗族红酸汤主要由乙醇提供,而水族红酸汤主要由4-乙基苯酚提供;感官评价显示,水族红酸汤的感官评分高于苗族酸汤。综上所述,水族红酸汤作为贵州红酸汤的一种,其品质和风味较优,具有很高的市场开发价值。

     

Effects of viscosity on the bitterness and astringency of grape seed tannin

To examine the separate effects of viscosity and sweetness on astringency, aqueous solutions of grape seed tannin (GST) were thickened with carboxymethyl cellulose (CMC) from 2 to 45 cP (experiment 1) or sweetened with 0 to 1.8 g/L aspartame (experiment 2). Trained subjects continuously rated astringency and bitterness in duplicate. Subjects were categorized by the salivary flow induced by citric acid and ability to taste n-propyl thiouracil (PROP). In experiment 1, maximum intensity and total duration of astringency were significantly decreased as viscosity rose, although time to maximum intensity of astringency was not affected. Maximum intensity and total duration of bitterness were not significantly affected by increasing viscosity; however, the onset of bitterness was significantly delayed. In experiment 2, increasing sweetness had no affect on any astringency parameter, although maximum intensity of bitterness was significantly decreased. Neither PROP nor salivary flow-status had any effect on perception of bitterness or astringency in either experiment.     

Umami Taste Enhancement of MSG/NaCl Mixtures by Subthreshold L-α-Aromatic Amino Acids

l ‐Phenylalanine (l ‐Phe) and l ‐tyrosine (l ‐Tyr) are L‐α‐aromatic amino acids that have recently been discovered to be important components of the savory fractions of soy sauce in addition to l ‐glutamate. Their effects are evaluated on the umami or savory taste of monosodium L‐glutamate (MSG), with or without sodium chloride (NaCl). Because l ‐Phe at subthreshold concentration (1.0 mM) significantly enhances an umami taste of a MSG/NaCl mixture (P= 0.000), combinations of 4 subthreshold concentrations (0, 0.5, 1.5, and 5.0 mM) of l ‐Phe with a weakly suprathreshold MSG (4.0 mM) and NaCl (80 mM) mixture were then rated for salty and umami intensities relative to those of standard solutions. L‐Phe was found to significantly enhance the umami tastes of the MSG/NaCl mixtures when it was added in a concentration range of 0.5 to 5.0 mM (P= 0.000). However, neither the umami taste of MSG alone nor the salty taste of NaCl alone was intensified. In a further experiment, l ‐Tyr at the 3 subthreshold concentrations (0, 0.5, and 1.5 mM) studied was shown to have the same activity as L‐Phe. The phenomenon of umami or savory enhancement by subthreshold aromatic amino acids in the soy sauce system has been established.     

不同脱苦涩处理刺梨果汁风味品质分析

以刺梨果汁为原料,采用感官评定方法结合电子舌技术,探讨不同苦涩味的脱除方法对刺梨果汁风味品质的影响,并确定最佳脱除条件。结果表明：刺梨汁整体味感以酸味、涩味和苦味为主。添加剂组合方法脱除刺梨汁苦涩味效果明显优于单一方法,其最佳脱苦涩味的方法为添加质量分数0.12%单宁酶和质量分数0.015%三氯蔗糖,该方法处理的刺梨汁感官评定分值最高、结果最佳、口感适宜、苦涩味最轻,经电子舌检测在苦味和涩味2 个传感器上的响应值最小。在食品风味评价中,应将电子舌技术结合传统感官评定方法进行分析,利于获得更准确、可靠的结论。     

The taste of calcium and magnesium salts and anionic modifications

Taste properties of divalent salts are complex. The first study examined the taste profiles of calcium chloride, magnesium chloride and magnesium sulfate. These divalent cation salts were characterized primarily by bitter taste, with additional sensations described as salty, metallic, astringent, sour and sweet, generally in decreasing order of intensity. A second study examined the taste properties of calcium salts other than chloride. Calcium gluconate, calcium glycerophosphate and calcium lactate had lower salty and bitter responses than equimolar concentrations of calcium chloride, an effect suggesting anionic inhibition.     

电子舌技术在食用盐模糊感官评价中的应用

以市售5种不同原料食用盐为主要研究对象,利用电子舌技术结合模糊感官评价技术方法,采用主成分分析等数学方法,建立食用盐模糊感官品质评价模型。结果表明:食用盐各感官指标的权重A={A_鲜味,A_咸味,A_涩味,A_苦味,A_丰富性}={0.32,0.23,0.22,0.18,0.05};综合分析结果显示,天然海盐的口感最佳。     

The phenolics of ciders: Bitterness and astringency

The bitterness and astringency of defined procyanidin fractions from bittersweet English ciders were assessed using a paired-comparison tasting technique. The results demonstrate that, while no one procyanidin can be uniquely identified with bitterness or astringency, bitterness is associated with oligomeric procyanidins reaching a maximum with the epicatechin tetramer whereas astringency is characteristic of higher-molecular-weight procyanidins. The effect of presentation media on taste response was also studied. High sugar and buffer strength suppressed the perceived bitterness, whereas ethanol increased bitterness but simultaneously decreased astringency. It is shown that the observed taste differences between two bittersweet ciders and the taste-modifying effect of ethanol can be explained satisfactorily by current theories of taste.     

初烤烟叶提取物中酸味关键成分的感官导向分析

为考察烟叶的酸味关键成分,利用凝胶渗透色谱(GPC)分离初烤烟叶的提取物,根据各流份滋味特征评价结果,合并酸味流份,得初烤烟叶提取物的酸味特征组分;建立酸味特征组分中乳酸、乙酰丙酸、苹果酸、富马酸、柠檬酸等5 种有机酸的离子色谱(IC)定量方法;依据定量结果,复配上述5 种有机酸的混合溶液,分别对酸味特征组分溶液和有机酸复配溶液进行滋味稀释分析(TDA);利用三点选配法(3-AFC)测定上述5 种有机酸在水中的味觉阈值,结合其在酸味特征组分中的质量分数,计算各有机酸的滋味活性值(TAV)。结果表明:①酸味特征组分溶液和有机酸复配溶液在TDA实验中表现出一致的最大稀释倍数,证明所考察的5 种有机酸是酸味特征组分中酸味的主要来源。②根据5 种有机酸的TAV推测其对酸味的贡献排序为苹果酸> 乳酸> 乙酰丙酸> 柠檬酸> 富马酸。      

新型发酵茶复合饮料的研究

以茶发酵液为主要原料,用猕猴桃汁进行勾兑,采用正交试验方法,探索最佳发酵工艺条件和配方,开发出色、香、味俱佳的复合型保健饮料。     

灰树花发酵复合保健饮料的研究

以灰树花发酵为主要原料,用猕猴桃汁进行勾兑,采用正交试验的方法,探索最佳发酵工艺条件和配方,开发出色、香、味俱佳的复合型保健饮料。     

Evaluation of the taste contribution of theaflavins in black tea infusions using the taste activity concept

The contribution of theaflavins to the astringent taste of black tea infusions has been investigated. The major benzotropolons theaflavin, theaflavin-3-gallate, theaflavin-3-gallate, theaflavin-3,3-digallate, and theaflavic acid were synthetically prepared by enzymatic oxidation of binary mixtures of the corresponding flavan-3-ols, purified by high-speed countercurrent chromatography, and then sensorially evaluated by means of a comparative duo test. The sensory analysis revealed that the theaflavins imparted a mouth-coating, astringent, and long-lasting oral sensation at the very back of the throat, and demonstrated the theaflavins to have by far lower oral thresholds than the astringent catechins; for example, the threshold concentration of theaflavin (0.016 mmol/L) is by a factor of 33 and 58 lower than those of its precursors epigallocatechin and epicatechin, respectively. In order to study the importance of these theaflavins as contributors to tea astringency, these benzotropolons were quantified in tea infusions and taste activity values were calculated from the quotient of their concentration in tea and their taste detection thresholds. Relating the taste activity values of the individual theaflavins to the overall astringency of the teas revealed that the theaflavins accounted for less than 0.1% of the overall astringency of the teas investigated. In consequence, the theaflavin concentration seems not to be a suitable measure for taste quality of tea infusions.