Isabel Lopez Galilea emphasized in her study that the addition of sugar during the roasting process increases the development of compounds with high anti-oxidant activity.

Galilea analyzed 11 varieties of commercial coffee and analyzed the coffee consumption habits of the inhabitants of Navarra, conducting 300 surveys.

The results showed that Navarrans consume an average of 125 ml, or 3.75 fluid ounces, of coffee per day, with consumption slightly higher among women. In addition, they primarily consume ground coffee resulting from a mixture of natural roast and torrefacto-roast coffees -- and the coffee is generally prepared with Italian or mocha coffee makers, followed by the filter, espresso and pump methods.

After confirming the increased anti-oxidant capacity of ground coffees roasted using the torrefacto process, Galilea showed how these properties were present in the brewed coffee -- the typical form of coffee consumption. The study discovered that espresso machines produce a drink with the highest anti-oxidant capacity, more than coffee produced by the Italian, filter and pump methods.

Anti-oxidants protect against free radicals -- a cause of premature aging and certain diseases.