Potential of furan formation in roasted coffee as influenced by species and roast degree

Furan is a food processing contaminant which is formed as part of the coffee volatile aroma components generated during roasting. Furan is classified as a “possible human carcinogen” and recent risk evaluations have indicated that the exposure to furan in the diet is a human health concern. It has been reported that roasted coffee contains the highest furan levels when compared to other foods. This may be associated to the higher temperatures used in the roasting process, which exceed most of other food processing procedures. In order to contribute to a better understanding of the factors affecting the formation of furan in coffee, Brazilian green coffee beans of Coffea arabica and Coffea canephora species were roasted to light, medium and dark roast degrees and analyzed in relation to furan content by using an in-house validated method based on gas chromatography coupled to mass spectrometry preceded by headspace solid phase microextraction. Furan was not detected in green coffees whereas levels between 911 and 5852 μg/kg were found in the roasted samples. When considering the species, higher furan levels were observed in samples of C. canephora within each roast degree. In relation to the roasting process, it was verified that furan levels significantly increased with the intensity of roasting for both species.