Sugars or carbohydrates are identified as the source of free radicals
in coffees, ersatz coffees, a number of other food flavouring and colo
uring agents formed by processes involving heating, and in beers and s
touts. The radicals are not derived from phenolic constituents, in con
trast to those in wine, and are unlikely to be due solely to the occur
rence of Maillard reactions.