Occurrence of furan in commercial samples of roasted coffee in Brazil

Furan is a food processing contaminant which occurs in several heat-treated foods, such as canned and jarred foods, coffee and cereal products. Furan is classified as a possible human carcinogen and recent risk evaluations have indicated that the exposure to furan by commonly consumed foods in the diet is a human health concern. Previous studies indicate that roasted coffee contains the highest furan levels in comparison to other products, with mean and maximum values of 1807 and 6900 μg/kg, respectively. So far, no data on the levels of furan in roasted coffee samples from Brazil is available in the literature. Therefore, the objective of this study was to validate a method based on gas chromatography coupled to mass spectrometry preceded by headspace solid phase microextraction (HS-SPME-GC/MS) for furan determination and evaluate the levels of the contaminant in roasted coffees available on the Brazilian market. Results of the validation showed good linearity over the range 0-9600 μg/kg. A comparison between curves set on aqueous standard solutions and on matrix revealed a non-significant matrix effect. Limits of detection and quantitation were 3 and 10 μg/kg, respectively. Recovery, repeatability and within-laboratory reproducibility were in satisfactory ranges. The content of furan in the analyzed samples varied from 250 to 5332 μg/kg. The lowest mean level was found in instant coffee (449 ± 271 μg/kg) whereas the highest mean concentration was observed in strong ground coffee packed under vacuum (4247 ± 1090 μg/kg). It is expected that these results will contribute to data accumulation for worldwide health risk assessment and be helpful in establishing approaches to lower the exposure of the population to furan from the consumption of coffee.