VANCOUVER - Coffee drinkers who prefer a dark roast may be getting more than just a buzz from their beverage of choice.

University of B.C. food scientists say their study shows that roasting coffee beans a dark brown produces antioxidant benefits linked to slowed aging.

Science student Yazheng (Ya-Jang) Liu and co-author Prof. David Kitts analyzed the complex mixture of chemical compounds created during the browning process.

They say their tests show that browning coffee beans under high temperatures creates the antioxidants.

The scientists say previous studies suggest antioxidants in coffee could be traced to caffeine or chlorogenic acid found in green coffee beans.

But their study, to be published in the journal "Food Research International," found that coffee beans lose 90 per cent of their chlorogenic acid during the roasting process.