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

Abstract

The effects of several slaughter methods on the quality of fresh and smoked trout and fresh gilthead seabream were evaluated during storage at 2 degrees C. Electrically stunned trout had slower ATP depletion of raw muscle and 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 after 15-20 min, whereas carbon dioxide-stunned fish appeared dead after 5 min. However, gilthead seabream group having slower ATP depletion also showed lower lipid oxidation of muscle during storage. In both species this could be due to the rapid conversion of xanthine dehydrogenase to xanthine oxidase induced by the rapid consumption of ATP. Xanthine oxidase, in the presence of redox iron and reintroduced oxygen, can produce hydrogen peroxide and, consequently, hydroxyl radicals.

From farm to fork: lipid oxidation in fish products. A review

“…Results from Giuffrida et al (2007) were in agreement with this explanation. Particularly, ice slurry slaughtered gilthead sea bream (S. aurata) showed higher (and then better) ATP/IMP levels (an indicator of less stressed fish) and to be less prone to lipid oxidation, as revealed by the MDA values, 0.158 mg MDA/ kg flesh against 0.227 mg MDA/kg flesh in CO 2 -slaughtered fish.…”

Flesh characteristics of pan-size triploid and diploid rainbow trout (<i>Oncorhynchus mykiss</i>) reared in a commercial fish farm

“…The pre-mortem conditions which alter the physiology of the fish have an impact on the post-mortem muscle biochemistry (e.g. pH or EC development) and this could influence the quality of the fish fillets-for example the colour, texture or WHC (JOHNSTON et al, 1999;THOMAS et al, 1999;GIUFFRIDA et al, 2007). Exercise or stress before slaughter results in an accelerated decrease of the pH due to higher lactate production in the muscle tissue (THOMAS et al, 1999;MORZEL et al, 2003, GIUFFRIDA et al, 2007.…”

“…pH or EC development) and this could influence the quality of the fish fillets-for example the colour, texture or WHC (JOHNSTON et al, 1999;THOMAS et al, 1999;GIUFFRIDA et al, 2007). Exercise or stress before slaughter results in an accelerated decrease of the pH due to higher lactate production in the muscle tissue (THOMAS et al, 1999;MORZEL et al, 2003, GIUFFRIDA et al, 2007. The age-or ploidy-related effects on the pH-and EC development -presented in the study -could be either related to a different response to pre-slaughter stress or exercise, and /or to a difference in the muscle characteristics that influence the muscle-to-meat transition.…”

Welfare of animals at slaughter and killing: a new regulation on the protection of animals at the time of killing

“…However, many slaughter methods have been developed not to minimise stress but to achieve product quality control, efficiency and processor safety (i.e. fish) (Channon et al 2000;Conte 2004;Shimshony and Chaudry 2005;Giuffrida et al 2007).…”