high content in polyphenol oxidase (PPO), enzyme that recognises a large variety ofmono-and polyphenols. The first scientists to use banana tissue were Sidwell and Rechnitz (1985), who developed what they called a “bananatrode”. They coupled a thin slice of banana pulpwith a Clark-type oxygen electrode tomeasure electrochemically the oxygen consumption due to the conversion of dopamine into 1,2-benzoquinone. Three years after them, Wang and Lin (1988) introduced the banana pulp into the carbonpaste, reducing the response time to dopamine to seconds. Instead of measuring the oxygen consumption, they measured the reduction of the quinone derivative back to catechol at negative potentials. Eggins et al. (1997) used a similar banana electrode to detect flavanols, such as catechins and their dimmers and trimmers, as indicators of beer quality.