Maillard Reaction Produces Antioxidants in Coffee

VANCOUVER, British ColumbiaThe antioxidants in coffee dont come from the bean itself, but rather from the roasting process, according to food scientists at the University of British Columbia. The prevailing antioxidants present in dark-roasted coffee brew extracts result from the green beans being browned under high temperatures

Previous studies suggested that antioxidants in coffee could be traced to caffeine or the chlorogenic acid found in green coffee beans, but our results clearly show that the Maillard reaction is the main source of antioxidants," says Yazheng Liu, an MSc student in the Faculty of Land and Food Systems (LFS) and lead author of the study.

In fact, the researchers found that coffee beans lose 90 percent of their chlorogenic acid during the roasting process.

Their findings will appear in a forthcoming issue of Food Research International and can be previewed at: http://dx.doi.org/10.1016/j.foodres.2010.12.037

The study sheds light on an area of research that has yielded largely inconsistent findings. While some scientists report increased antioxidant activity in coffee made from dark roasted beans, others found a decrease. Yet other theories insist that medium roast coffees yield the highest level of antioxidant activity.