Hold the Espresso for Now: Confessions of a Coffee Drinker

I am not a morning person. I don’t think I will ever be a morning person. Nighttime is when my mind seems to come alive; it is the best time for me to think and create. In short, I am a night owl; I always have been. Even though I was the youngest in my family, I gave up Saturday morning cartoons as soon as my older, and appallingly morning-oriented, sister did. And, although I was not willing to give up my family’s tradition of Saturday morning pancake breakfasts, I was not averse to crawling back into bed after breakfast if I could.

Despite my nocturnal tendencies, I managed, through sheer determination in high school and careful selection of my schedule in college, to avoid the need for morning coffee. That all ended with my first “real” job. Even the warm sunlight of southern California wasn’t enough to coax me awake and alert at 6:30 in the morning. Fortunately my apartment was not that far from a coffee shop. And so, my love of espresso and all other things coffee was born.  

Ever since then, a coffee maker of some sort has held a prominent position on my kitchen counter. For a while the coffee pot was joined by a small, inexpensive, espresso machine.  I soon found that the preparation and clean up time for making my own espresso was not time efficient, and I was not so enamored with coffee that I was willing to get up earlier to fix it myself. And so I have made do with coffee from an automatic coffee maker, which can have the coffee ready when I wake up. Recently I thought that maybe technology had caught up with me when I saw an espresso machine that makes expresso from prepackaged cartridges of coffee, and there was an automatic model.

Before I could get too excited I came across a paper in a journal called Food Chemistry (1) that somewhat cooled my enthusiasm (or added to the cooling that had already occurred when I saw the price [~$350] of my dream espresso machine). A study conducted in Spain found much higher levels of furan (C4H4O), a chemical recently classified as a possible human carcinogen, in espresso brewed using prepackaged coffee packets and a compatible espresso machine compared to that found in drip coffee or espresso from ground coffee. Furan is generated when the green coffee beans are roasted. This is most likely a result of the thermal breakdown of carbohydrates, pyrolysis of sugars at high temperatures, oxidation of polyunsaturated fatty acids and decomposition of ascorbic acid.

The espresso prepared using the prepackaged cartridges contained 117–244ng/ml of furan compared to 43–146ng/ml in that prepared from regular ground coffee. There are two things that most likely contribute to this increase in furan in the cartridge espresso, one is that the process of packaging and hermetically sealing the cartridge prevents to loss of furan during handling of the coffee beans and grounds. The second is the higher pressure used by the machines that use these cartridges.

Even with the elevated levels of furan in the cartridge espresso, the authors calculated that the average male consumes 3.6–26.3µg/person and the average female consumes 2.4–17.5µg/person of furan daily (based on 488 participants of a survey). The acceptable daily intake (ADI) of furan is expressed in µg/ kg body weight (bw)/day, and that number is currently 2µg/kg bw/day with a safety factor of 1000. Based on this study, the daily furan intake calculates to 0.03–0.25µg/kg bw/day for men and 0.03–0.2525µg/kg bw/day for woman.  Both of these numbers are well below the ADI value for furan.

So it seems that drinking one or two cups of espresso prepared using an automatic machine and prepackaged coffee cartridges would not result in too much furan. This is undoubtedly good news for the hundreds of thousands of people who already own one of these machines. As for me, I think that I will stick to my old, steadfast and true coffee maker, with the occasional stop at the coffee shop.


  1. Altaki, M.S. and Galceran, M.T. (2011) Occurrence of furan in coffee from Spanish market: Contribution of brewing and roasting. Food Chemistry 126, 15270–1532.
The following two tabs change content below.
Kelly Grooms

Kelly Grooms

Scientific Communications Specialist at Promega Corporation
Kelly earned her B.S. in Genetics from Iowa State University in Ames, IA. Prior to coming to Promega, she worked for biotech companies in San Diego and Madison. Kelly lives just outside Madison with her husband, son and daughter. Kelly collects hobbies including jewelry artistry, reading, writing and knitting. A black belt, she enjoys practicing karate with her daughter as well as hiking, biking and camping.

One thoughtful comment

  1. Thanks for this info, Kelly. Nice to think about espresso on a dark, cold April day. You make me feel better about making plain, ol’ drip coffee at home…as well as enjoying the occasional coffee shop stop. Is there a familiar story line here…like processed foods, perhaps processed coffee products are not the best for us?
    Signed, A morning person and coffee lover

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.