Research on the Changes to the Lipid/Polymer Membrane Used in the Acidic Bitterness Sensor Caused by Preconditioning
| Autor: | Kiyoshi Toko, Junpei Noda, Rui Yatabe, Hidekazu Ikezaki, Yuhei Harada |
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| Rok vydání: | 2016 |
| Předmět: |
Taste
Monosodium glutamate Synthetic membrane 02 engineering and technology lcsh:Chemical technology 01 natural sciences Biochemistry Article Analytical Chemistry Contact angle chemistry.chemical_compound Adsorption lipid/polymer membrane lcsh:TP1-1185 taste sensor bitterness sensor CPA value Electrical and Electronic Engineering Instrumentation chemistry.chemical_classification Membrane potential Chromatography 010401 analytical chemistry Polymer 021001 nanoscience & nanotechnology Atomic and Molecular Physics and Optics 0104 chemical sciences Membrane chemistry 0210 nano-technology |
| Zdroj: | Sensors; Volume 16; Issue 2; Pages: 230 Sensors, Vol 16, Iss 2, p 230 (2016) Sensors (Basel, Switzerland) |
| ISSN: | 1424-8220 |
| DOI: | 10.3390/s16020230 |
| Popis: | A taste sensor that uses lipid/polymer membranes can evaluate aftertastes felt by humans using Change in membrane Potential caused by Adsorption (CPA) measurements. The sensor membrane for evaluating bitterness, which is caused by acidic bitter substances such as iso-alpha acid contained in beer, needs an immersion process in monosodium glutamate (MSG) solution, called "MSG preconditioning". However, what happens to the lipid/polymer membrane during MSG preconditioning is not clear. Therefore, we carried out three experiments to investigate the changes in the lipid/polymer membrane caused by the MSG preconditioning, i.e., measurements of the taste sensor, measurements of the amount of the bitterness substance adsorbed onto the membrane and measurements of the contact angle of the membrane surface. The CPA values increased as the preconditioning process progressed, and became stable after 3 d of preconditioning. The response potentials to the reference solution showed the same tendency of the CPA value change during the preconditioning period. The contact angle of the lipid/polymer membrane surface decreased after 7 d of MSG preconditioning; in short, the surface of the lipid/polymer membrane became hydrophilic during MSG preconditioning. The amount of adsorbed iso-alpha acid was increased until 5 d preconditioning, and then it decreased. In this study, we revealed that the CPA values increased with the progress of MSG preconditioning in spite of the decrease of the amount of iso-alpha acid adsorbed onto the lipid/polymer membrane, and it was indicated that the CPA values increase because the sensor sensitivity was improved by the MSG preconditioning. |
| Databáze: | OpenAIRE |
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