Influence of roasting and brew preparation on the ochratoxin A content in coffee infusion.
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.
Pérez De Obanos
A
A
Food Science and Toxicology Department, University of Navarra, Pamplona, Spain.
González-Peñas
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E
López De Cerain
A
A
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D040503:Coffea / Q000737:chemistry; D003069:Coffee / Q000737:chemistry*; D004781:Environmental Exposure / Q000009:adverse effects; D005506:Food Contamination / Q000032:analysis; D006358:Hot Temperature; D006801:Humans; D009183:Mycotoxins / Q000032:analysis*; D009793:Ochratoxins / Q000032:analysis*; D015203:Reproducibility of Results
D003069:Coffee; D009183:Mycotoxins; D009793:Ochratoxins; C025589:ochratoxin A