The results of DPPH radical-scavenging activity and reducing power of fish protein films are shown in Fig. 2 and Fig. 3, respectively. Fish protein films showed antioxidant activity that can be due to the presence of free sulfhydryl groups and other aminoacids such as tryptophan, methionine, and tyrosine on hake fish proteins, as mentioned by Taguchi, Iwami, Kawabata, and Ibuki (1988) and Faraji, McClements, and Decker (2004). The incorporation of essential oils significantly increased the DPPH radical-scavenging activity of fish protein films. The highest antioxidant activity was obtained with clove and garlic films (72% of inhibition). The differences found in the antioxidant activity of films with different essential oils, are due to different compounds with antioxidant activity in essential oils composition. The DPPH radical-scavenging activity of films with origanum and clove was lower than that of the free essential oil, whereas garlic films revealed higher activity than the essential oil itself. Such decrease could be due to interactions between the components of films and essential oils that could no longer be available to interact in the antioxidant activity reactions, and to the loss of volatile compounds of essential oils during the films drying process. In contrast, the increase in the antioxidant activity observed with garlic films might be due to the presence of di-2-propenyldisulfide and di-2-propenyltetrasulfide in this essential oil, both with disulfide bonds that might be cleaved in the film forming solutions and able to act as scavenging hydroxyl radicals increasing the antioxidant activity in the DPPH method, and not in the ferric reducing power method.