Determination of acrylamide in filtered coffee drink: comparing different preparation methods

Acrylamide is a potentially carcinogenic contaminant formed during the thermal processing of food from reducing sugars and asparagine. In coffee, its formation occurs during roasting, with higher concentrations in lighter roast coffees. Considering coffee as one of the main sources of exposure to acrylamide in the diet, the objective of this study was to evaluate the influence of the method of preparation of the beverage and the type of filter on the concentrations of acrylamide in the ready-to-eat product. The samples were prepared in triplicate, using a fixed ratio of 1 g of coffee powder to 10 mL of water, by infusion (water at 97 ± 3°C) or boiling (mixture of powder and water maintained for 2 minutes after the beginning of boiling), followed by filtration in a paper, cloth or metal filter (n = 18). For the preparation, roasted and ground coffee of medium roast, purchased in local commerce, was used. Acrylamide quantification was performed in coffee powder and beverages by high-performance liquid chromatography coupled to sequential mass spectrometry (LC-MS/MS), after extraction by protein precipitation (Carrez I and II), liquid-liquid extraction with ethyl acetate, evaporation and purification in SPE cartridge. The final extract was filtered and injected into the LC-MS/MS. The data were submitted to the Shapiro-Wilk normality test, which indicated a non-normal distribution (p < 0.05), and analyzed by the non-parametric Kruskal-Wallis test, followed by the Dunn test for multiple comparisons. The results were expressed as mean ± standard deviation. In coffee powder, the concentration of acrylamide was 116.97 ± 0.69 μg/kg. In the beverages, concentrations ranged from 10.63 µg/L to 17.16 µg/L. Comparing the methods, samples prepared by boiling showed higher average concentrations (14.73 µg/L) than those prepared by infusion (13.15 µg/L). Among the filters, the metallic one resulted in the highest average levels (15.11 ± 1.50 µg/L), followed by cloth (13.44 ± 1.19 µg/L) and paper (12.78 ± 2.26 µg/L). The combination of boiling and metallic filter presented the highest levels, possibly due to the longer contact time between the powder and water, favoring extraction. Paper and cloth filters may retain part of the acrylamide, while the metallic filter allows greater passage of the compound. These results reinforce the importance of guiding consumers and the industry about methods that minimize the occurrence of acrylamide in the diet.