VANCOUVER, British Columbia, Feb. 4 (UPI) -- Canadian researchers say roasting is the reason coffee provides antioxidant benefits that help people fight aging.
Lead author Yazheng Liu and co-author David Kitts, both of the University of British Columbia, say antioxidants present in dark roasted coffee brew extracts result from the green beans being browned under high temperatures.
The researchers analyzed the chemical compounds produced during the bean's browning process -- the "Maillard reaction." In the 1900s, French chemist Louis-Camille Maillard studied the way heat affects the carbohydrates, sugars and proteins in food when grilling steaks or toasting bread.
"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," Liu says in a statement.
However, Kitts, a food science professor and director of the food, nutrition and health program, says coffee beans lose 90 percent of their chlorogenic acid during the roasting process.
Antioxidants help in removing free radicals -- the end products of metabolism which have been linked to the aging.
The findings appear in a forthcoming issue of Food Research International.