BEHAVIOR OF OCHRATOXIN-A DURING GREEN COFFEE ROASTING AND SOLUBLE COFFEE MANUFACTURE

As considerable inconsistencies are found in the literature regarding the influence of roasting and subsequent operations on the ochratoxin A (OTA) content of green coffee, experiments were undertaken to assess the evolution of OTA along an industrial soluble coffee manufacturing line. Both the variability and the amount of OTA naturally present in a lot of Thai Robusta green coffee were drastically reduced during so luble coffee manufacture. A small proportion of OTA was eliminated dur ing green coffee cleaning, but the most significant reduction took pla ce during roasting. The roast and ground coffee contained only 16% of the OTA originally present in the green coffee. Two phenomena are resp onsible for the elimination of OTA during roasting: a thermal degradat ion and a removal with chaff. Thermal degradation is the most importan t route of elimination, with < 20% accounted for by the chaff. A furth er 20% reduction was observed during soluble coffee manufacture, so th at the powder contained only 13% of the OTA initially present in the g reen beans.