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  • QA 170
    Question:
    Which process was used to arrive at the conclusion that ochratoxin is mostly eliminated during roasting?
    Background:
    Different papers state that the roasting process eliminates 50 to 85% of the ochratoxin that is encountered in some green coffees. Which roasting processes have been used to determine this: traditional, fluidisation or high yield? Would the traditional process (roasting at 210-250 degrees centigrade during some 15 minutes) not produce the best results in this respect?
    Asked by:
    Roaster - Switzerland
    Answer:

    The standard commercial roasting processes currently in use all reduce Ochratoxin A (i.e. OTA) levels (where OTA is present) significantly.

    The cleaning and roasting of green coffee beans is proven to reduce OTA levels by as much as 85% regardless of the time or temperature involved in the roasting procedure. This applies to all green coffee beans, so robusta and arabica both.

    This has been proven in ten or more commercial roasting application trials, which are not to be confused with laboratory experiments using artificially contaminated green coffee beans  that may produce alternative answers. OTA balance has been established after the determination at each step of the industrial process on raw green beans, roasted beans and chaffs after cleaning and roasting. For green coffees with over 4 ppb (parts per billion) of OTA, reductions during roasting were reported by a factor 3 up to a factor 10 down from the original level in the green beans. At lower starting levels in the green beans the reported reductions during roasting are more variable.

    These findings are accepted by the European Union, the European Food Safety Authority (EFSA) and the Codex Alimentarius FAO/WHO as matters of principle.

    In addition other studies have shown that standard decaffeination processes remove about 75% of any OTA that may be present before decaffeination. This is plausible, as OTA is quite soluble in the extraction media normally used in decaffeination.

    For an introduction to OTA and related issues see Section 12.08 of the Coffee Guide. For more extensive and scientific information we suggest to visit www.coffee-ota.org which is the website of the OTA Project based at the Food and Agricultural Organizations of the United Nations - FAO.

    Posted 16 November 2007

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