Caffeoyl-tyrosine and Angola II as characteristic markers for Angolan robusta coffees

The composition of the chlorogenic acid-rich fractions of 10 commercial coffee samples from five countries and including the four major coffee-producing regions of Angola were analysed by HPLC. The presence of two chlorogenic acid-like components, previously reported as unique to and characteristic of Angolan robustas, was confirmed for three of the main Angolan coffee producing regions. Only one of these two components caffeoyl-tyrosine, was found in the sample from Cabinda. Neither could be detected in the coffee samples from Cameroon, Indonesia, Ivory Coast or Zaíre. It was established that, if present in the green beans, both of these components survive a medium intensity roasting and are extracted into the coffee brew at concentrations in the range 1.2–6.7mg/100 ml.