influence of the degree of roasting on the acrylamide content and
extractability, four green coffee samples (two arabicas, Brazil and
Honduras, and two robustas, Uganda and Ivory Coast) were roasted
at three different roasting degrees as described in the experimental
section. Organic roast loss and colours achieved are summarised in
Table 3, together with the results for acrylamide. The total acrylamide
content was calculated for 6.5 g of ground coffee (cake
weight) and the acrylamide extractability obtained by the following
formula: espresso content/cake content 100.
In a general way, acrylamide levels in ground coffee (both arabica
and robusta) significantly decreased (p < 0.05) with increased
roasting period, for each individual sample. In fact, very high levels
of acrylamide were detected in the lightest roasted coffee samples,
with maximum of 1240 and 2190 lg/kg, for arabica and robusta,
respectively (Table 3). Also Taeymans et al. (2004) reported that
levels of about 2000 lg/kg were observed at the early stages in
the process of coffee beans roasting. Moreover, the amount present
in dark roasts (Table 3) corresponds only to 15% and 23% of that
present in light roasts, for arabica and robusta, respectively. Therefore,
considering all the samples together, mean loss of about 80%