Acrylamide in Coffee: What Roasters Should Know

Acrylamide develops naturally in the coffee roasting process. Creative Commons photo by John Lodder.

The U.S. Food and Drug Administration yesterday released a consumer warning on acrylamide, a naturally occurring chemical found in cooked foods — including coffee — that is known to cause cancer in animals.

The warning has already been picked up by numerous mainstream sources, which have casually cited coffee as one of the offending foods, although it’s worth noting right away that acrylamide cause in the roasting process is dramatically reduced after ground coffee is brewed. Despite this fact, a small consumer uproar is sure to be upon us, so now is as good a time as any to review what we know about acrylamide.

The chemical compound was first discovered by Swedish scientists in 2002, although it is widely considered to have been present for as long as humans have been baking, frying and roasting foods. Most often found in plant-based products, it develops when foods containing sugar and an amino acid called asparagine are cooked at high temperatures. In animal testing since its initial discovery, high levels of acrylamide have been found to cause tumors and a high incidence of cancer.

Along with its latest warning, the FDA is for the first time putting together a draft document for food producers (in this case, coffee roasters) on acrylamide in foods. The document is currently in the comment period.

In a 2011 story in Roast Magazine highlighting the potential effects of Califonia’s Proposition 65 on the coffee industry, National Coffee Association President Robert Nelson provided the most comprehensive overview of acrylamide in coffee to date, writing:

For coffee, the issue of acrylamide arises in the roasting process. As coffee beans are roasted, natural sugars and moisture enable the desirable browning process, which chemically creates some acrylamide. The exact mechanisms of acrylamide’s formation in coffee may involve asparagine and other possible pathways. However, the highest level of the compound occurs at a roasting level too light for consumer preferences, after which it begins to degrade significantly during further roasting. Completed roasting leaves only a fraction of the original acrylamide levels in the bean. Moreover, there’s very little acrylamide left in brewed coffee as it is consumed.

In fact, the highest levels found by FDA researchers are in store-bought ground coffees (The FDA compiled a list of acrylamide test results for some of the most popular store-bought and brewed coffees — primarily instant — in the U.S).

Nelson continues by considering what coffee roasters can do to reduce or eliminate the presence of acrylamide in coffee. Unfortunately, the answer is probably very little:

Other products, such as fries, chips, cereals and crackers, have had some success in reducing acrylamide levels by altering cooking processes and ingredient profiles. But no mitigation methods have proven workable in reducing the levels formed during coffee roasting despite strong research efforts. Roasting coffee darker, for instance, makes taste and aroma unpalatable to consumers. Other approaches, such as steam roasting, have not shown any significant reduction in acrylamide levels in finished products. However, work is under way on a finding that acrylamide appears to degrade when roasted coffee is stored over time. Because that also impacts freshness, though, it may not be a workable solution.

Read Nelson’s full story on Prop 65 and acrylamide here.