Coffea arabica beans were roasted in an oven at 200 C for increasing lengths of time under vacuum (i.e.
0.15 kPa). The samples were then analysed for colour, weight loss, acrylamide concentration and sensory
properties. Data were compared with those obtained from coffee roasted at atmospheric pressure (i.e.
conventional roasting), as well as at atmospheric pressure for 10 min followed by vacuum treatment
(0.15 kPa; i.e. conventional-vacuum roasting). To compare the different treatments, weight loss, colour
and acrylamide changes were expressed as a function of the thermal effect received by the coffee beans
during the different roasting processes. Vacuum-processed coffee with medium roast degree had approximately
50% less acrylamide than its conventionally roasted counterpart. It was inferred that the low
pressure generated inside the oven during the vacuum process exerted a stripping effect preventing
acrylamide from being accumulated. Vacuum-processed coffee showed similar colour and sensory properties
to conventionally roasted coffee.
