Influence of Slaughtering Method on Some Aspects of Quality of Gilthead Seabream and Smoked Rainbow Trout

The effects of several slaughter methods on the quality of fresh and smoked trout and fresh gilthead seabreamwere evaluated during storage at 2◦C. Electrically stunned trout had slower ATP depletion of raw muscleand lower lipid oxidation in smoked product during storage. Gilthead seabream immersed in an ice slurry(IS group) after the harvest showed a more regular ATP depletion than in fish exposed to CO2. Nevertheless,in the case of the IS group, self-initiated behaviour, response to handling and breathing all ceased only after15–20 min, whereas carbon dioxide-stunned fish appeared dead after 5 min. However, gilthead seabream grouphaving slower ATP depletion also showed lower lipid oxidation of muscle during storage. In both species thiscould be due to the rapid conversion of xanthine dehydrogenase to xanthine oxidase induced by the rapidconsumption of ATP. Xanthine oxidase, in the presence of redox iron and reintroduced oxygen, can producehydrogen peroxide and, consequently, hydroxyl radicals.[...