Reliable estimation of dietary exposure to furan from coffee: An automatic vending machine as a case study

- Furan levels in coffee drinks acquired from coffee vending machines were determined.
- Real furan levels of exposure from coffee to humans were estimated.
- Coffee kept at room temperature for 5 min showed furan losses of 74.3%.
- Furan content decreased 93.8% when coffee was stirred for 5 min.
- Exposure to furan from coffee implies a low risk to human health.

Worldwide Food Safety Agencies have classified furan as carcinogenic and cytotoxic due to its effects in animal studies, and it has been associated with harmful effects to human health. It has been pointed out that coffee consumption is the major contributor to dietary furan exposure for adults. However, furan is highly volatile and its losses due to volatilization in the cup during the time expend to consume the coffee brew should be taken into account for a realistic estimation of the levels of furan exposure for humans. The aim of this study was to estimate the furan exposure to humans considering the time for consumption after preparation of the fresh beverage. Furan was determined in coffee brews acquired from automatic coffee vending machines placed in areas with high density of population. Furan levels in coffee beverages ranged from 11 to 262 ng/mL (mean = 171 ± 59.8). Furthermore, five different scenarios were settled immediately after the acquisition of coffee brews from the coffee vending machines in order to assess a realistic estimation of furan exposure. Furan content in coffee decreased from 170 up to 4 ng/mL after simulating the behavior of coffee consumption (~ 74% after standing at room temperature for 5 min, ~ 64% after stirring for 30 s and standing at room temperature up to 5 min, ~ 94% after stirring for 5 min, ~ 97% after 8 h in a sealed thermo and ~ 37% after being cooled one week at a fridge). These results suggest that it is mandatory to establish very precisely the furan levels in the final ready-to-drink beverage in order to obtain reliable estimations of the daily intake from coffee and to define potential strategies for mitigation. Furan intake from coffee ranged from 0.02 to 0.43 μg/kg b.w./day, resulting in a mean exposure of 0.31 μg/kg b.w./day.