Influence of roasting and brew preparation on the ochratoxin A content in coffee infusion

Food Addit Contam. 2005 May;22(5):463-71. doi: 10.1080/02652030500090042.


A study of the effect of coffee processing in the ochratoxin A (OTA) level has been carried out from the green beans to the drinking form. The analysis of OTA has been carried out by an in-house validated HPLC method with fluorescence detection. The limits of detection were 0.04 microg/kg for green and roasted coffee, and 0.01 microg/L for coffee brew. Thirty-six green coffee samples of different origin (Colombia, Costa Rica, Brazil, Vietnam, India and Uganda) were analysed. The highest concentrations of OTA were found in Vietnamese samples -- Robusta species treated by dry processing -- (range 0.64-8.05 microg/kg), that also showed the highest percentage of defective beans (7.6%). These contaminated samples were roasted in a process that controlled loss of weight and color, as in the industry. A mean reduction of 66.5% was obtained, but the reduction seems to be heterogeneous. Coffee brew was prepared by the three brewing processes more utilized in Europe: moka, auto-drip and espresso. A reduction of the OTA level has been attained, being greater when using a espresso coffee maker (49.8%) than when using auto-drip (14.5%) or moka brewing (32.1%). Therefore, the method of coffee brew preparation plays a key role in the final OTA human exposure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, High Pressure Liquid / methods
  • Coffea / chemistry
  • Coffee / chemistry*
  • Environmental Exposure / adverse effects
  • Food Contamination / analysis
  • Hot Temperature*
  • Humans
  • Mycotoxins / analysis*
  • Ochratoxins / analysis*
  • Reproducibility of Results


  • Coffee
  • Mycotoxins
  • Ochratoxins
  • ochratoxin A