Abstract
The concentrations of polyphenols in green tea infusions were analyzed using a newly developed polyphenol sensor. The principle of the sensor lays in the measurement of a decrease in hydrogen peroxide using a peroxidase-ferrocene-carbon paste electrode. First, polyphenols and peroxide was added to a measurement cell filled with a buffer. Second, soluble peroxidase was added to it. The enzyme oxidized the polyphenols and the concentration of hydrogen peroxide decreased according to the amount of polyphenols. The concentration of polyphenols was monitored by the decrease of current at the electrode. It needed less than nine minutes to measure a tea infusion. The results obtained by this method showed high correlation to those measured using high performance liquid chromatography. This method was applicable to canned tea drink by adding ascorbate oxidase to the buffer.
