Stability of frozen fillets from silver catfish anesthetized with essential oil of Lippia alba prior to electrical stunning or hypothermia

摘要

The effects of anesthesia with essential oil (EO) of L. alba prior to electrical stunning or hypothermia were evaluated on the stability of silver catfish fillets during frozen storage. Electrically stunned fish had the greatest increase in lipid oxidation along the storage and previous anesthesia with EO potentialized this effect. Fish stunned by hypothermia with no previous anesthesia had higher lipid oxidation in the flesh immediately after slaughtering, which probably contributed to accelerate protein oxidation along the storage. Fish stunned by hypothermia had the highest springiness value by the end of storage and the highest changes in instrumental color along the storage, whereas electrically stunned fish had delayed protein oxidation and smaller color and texture changes during frozen storage. Thus, hypothermia induced greatest changes in physicochemical markers and previous anesthesia with the EO of L. alba did not prevent these changes and did potentialize lipid oxidation induced by electrical stunning.