Taste Sensor

Abstract

88 Essentials of Machine Olfaction and Taste Essentials of Machine Olfaction and TasteRecently, researchers have been attempting to develop biosensors using biological tissue such as taste cells and receptors by applying genetic engineering technologies [56][57][58]. Whereas the reproducibility and stability of usable sensors should be improved, this kind of e-tongue might be promising as a future sensing device. Suslick's group analyzed liquids such as beer and soft drinks using a colorimetric cross-sensitive sensor array that comprises multiple chemically responsive dyes [59][60][61], and furthermore, tried to identify and characterize lung cancer by measuring exhaled breath using the same principle and device [66].Electronic tongues are aimed at discriminating and analyzing foods and beverages and are well known as sensing technologies that greatly contribute to quality management. Aissy Inc., Japan, a venture from Keio University, provides accurate analysis using its original taste sensors and services useful for the development of new products and marketing in the food industry [67].There are two types of commercialized electronic tongue in the world [7,8,68]. One is the taste sensing systems SA402B and TS-5000Z (Intelligent Sensor Technology Inc., Japan), which is usually called the taste sensor, and another is the Astree II e-tongue (Alpha MOS, France). Taste Sensor 93 PrincipleMembranes of taste sensors consist of lipids, plasticizers, and polyvinyl chloride (PVC). The following is the procedure for fabricating a taste sensor electrode:1. The necessary types and amount of lipid(s) and plasticizer(s) are added to tetrahydrofuran (THF) and mixed for 1 h. 2. PVC is added to the solution and then mixed for another 1 h. 3. The mixture is poured in to a petri dish to dry it at room temperature for 3 days. 4. A lipid/polymer membrane approximately 200 µm thick is created in the dish and then attached to the surface of a sensor probe using a solution of 800 mg PVC and 10 ml THF as an adhesive. 5. After 2 days of drying, the taste sensor electrode is complete. Figure 4.2 shows the chemical structures of the lipids and plasticizers used [123]. Taste sensor electrodes have various characteristics depending greatly on the types and amounts of lipids and plasticizer incorporated. This will be described further in Section 4.3.6.Measurement by the taste sensor is based on the potentiometric principle, and therefore, the electrical potentials between working electrodes for taste sensing and a reference electrode are measured. These electrodes use a silver wire coated with silver chloride (AgCl). Before the measurement, these electrodes, which are filled with a solution of 3.33 M potassium chloride and saturated AgCl solution as the inner solution, should be preconditioned for at least 2 days to stabilize the electrical potential. After the preconditioning, the electrodes are connected to an amplifier to measure the electrical potentials difference and are converted to digital code by a digital voltmeter and subsequently ...

Metabolome Analysis Identified Okaramines in the Soybean Rhizosphere as a Legacy of Hairy Vetch

“…Soil samples were analyzed by taste sensors (Toko et al, 2016) based on chemical interactions to lipid polymer membranes (Tahara and Toko, 2013). Details are described in Supplementary Methods.…”

A Quantitative Method for Acesulfame K Using the Taste Sensor

“…Using a lipid polymer membrane as the sensing part, the taste sensor is designed to have a characteristic called global selectivity as a goal. The global selectivity means that the taste sensor can respond to each taste quality by classifying enormous kinds of chemical substances into five kinds of groups (sourness, saltiness, bitterness, sweetness, and umami) in accordance with the physicochemical properties of each basic taste quality, such as hydrophobicity and iconicity [17][18][19][20]. The taste sensor is designed and developed with global selectivity to distinguish different tastes, which is its main difference from other e-tongues.…”

“…In this study, the sweetness sensor for high-potency sweeteners consists of TDAB, NPOE and PVC, which we developed in a previous study [29]. The saltiness sensor consists of TDAB, TDA, DOPP and PVC [18]. value, which is caused by both hydrophobic interaction and electrostatic interaction [22,30].…”

“…However, there is a difference from other sensors: the taste sensor is developed with the goal of global selectivity [17]. Global selectivity means that each sensor can respond to a certain taste quality selectively [18]. By adjusting the composition and content of the lipid and plasticizer, sensors for different tastes are made.…”

Discrimination of Apple Liqueurs (Nalewka) Using a Voltammetric Electronic Tongue, UV-Vis and Raman Spectroscopy

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