Supercritical fluid extraction as a potential mitigation strategy for the reduction of acrylamide level in coffee

The removal of acrylamide from coffee through supercritical CO2 extraction has been investigated for the first time. Two steps were performed: a pre-roasting treatment and a supercritical extraction process. The main aim of this first work was to investigate the feasibility of the process more than the impact of the treatment on the organoleptic properties of coffee. The efficiency of acrylamide removal was checked by measuring its content in the coffee beans before and after the supercritical treatment. The role of temperature, pressure, extraction time and the addition of a modifier (ethanol) was examined.The supercritical treatment did not affect the caffeine content of coffee and a maximum extraction efficiency of 79% was found for acrylamide. While a pressure variation did not significantly affect the results, temperature affected the extraction process at the highest extent. The addition of ethanol resulted in a significant increase in the extraction performance due to the change in polarity of the supercritical solvent mixture. The best working conditions in the experimental range here investigated were 100 °C, 200 bar and 9.5% w/w ethanol.

► Two steps were performed: pre-roasting and supercritical extraction.
► Temperature affected the extraction process more than pressure.
► Addition of ethanol changed the solvent polarity and increased the extraction yield.
► The highest extraction yield of 79% was found at 100 °C, 200 bar and 9.5% ethanol.
► The supercritical treatment did not affect the caffeine content of coffee.