The generation of a chain-breaking antioxidant capacity has been analyzed in butter cookies, as a function of the cooking time. A kinetics approach was used, by which the antioxidant capacity of aqueous extracts of cookies was measured in terms of equivalence by weight of a reference antioxidant. A diazo compound was used to generate at constant rate peroxyl radicals, and the reporting reaction was the bleaching of crocin in the presence of these radicals. Results indicated that during the first 20−30 min of cooking, when browning takes place, an antioxidant capacity accounting for up to 5 g of Trolox is produced in 100 g of dried aqueous extracts of the cookies. This result supports the concept that functionally relevant antioxidants are generated by Maillard reaction. Keywords: Maillard reaction; lipid oxidation; free radical scavenger; bakery product