Beta-cyclodextrin/surface plasmon resonance detection system for sensing bitter-astringent taste intensity of green tea catechins.
To develop a methodology for creating a sensor with a receptor for specific taste substances, we focused on constructing a sensing system for the bitter-astringent taste intensity of green tea catechins: (-)-epigallocatechin-3-O-gallate (EGCg), (-)-epicatechin-3-O-gallate (ECg), (-)-epigallocatechin (EGC), and (-)-epicatechin (EC). (1)H NMR titration experiments revealed that beta-cyclodextrin was an adequate receptor for sensing the bitter-astringent taste intensity of catechins. A surface plasmon resonance (SPR) system immobilized beta-cyclodextrin indicated larger responses for the gallate-type catechins in comparison to the non-gallate-type catechins. These responses corresponded to the tendency of the bitter-astringent taste intensity of the catechins felt by humans. Furthermore, the SPR system detected the larger stability of the complex between the gallate-type catechins and beta-cyclodextrin, which was interpreted as the aftertaste produced in humans by the gallate-type catechins. These results demonstrate that the beta-cyclodextrin/SPR system can sense the bitter-astringent taste intensity of the green tea catechins similar to human gustation. The methodology presented in this study can be used as a basic strategy for developing taste sensors with specific receptor functions.
Hayashi
Nobuyuki
N
National Institute of Vegetable and Tea Science, National Agriculture and Food Research Organization, Shimada, Shizuoka, Japan. hayn@affrc.go.jp
Chen
Ronggang
R
Hiraoka
Masamitsu
M
Ujihara
Tomomi
T
Ikezaki
Hidekazu
H
D015374:Biosensing Techniques / Q000379:methods*; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000032:analysis*; D006801:Humans; D010936:Plant Extracts / Q000032:analysis*; D020349:Surface Plasmon Resonance / Q000379:methods*; D013649:Taste; D013662:Tea / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000032:analysis*
D010936:Plant Extracts; D013662:Tea; D047392:beta-Cyclodextrins; D002392:Catechin; C031215:betadex