Stress assessment, quality indicators and shelf life of three aquaculture important marine fish, in relation to harvest practices, water temperature and slaughter method

Abstract

The objective of this study was to evaluate the effect of harvest practices and slaughter method on stress, quality and shelf life of whole fish (gilthead sea bream, European sea bass and red sea bream) towards the development of a humane slaughter practice. The use of hook and line resulted in significantly lower plasma cortisol and glucose in European sea bass and gilthead sea bream. Water temperature at harvest affected significantly the concentrations of stress indicators (plasma cortisol and glucose), mainly in European sea bass and gilthead sea bream. No significant differences were observed between the harvesting methods, regarding fish appearance, microbial spoilage and sensory scoring and subsequently shelf life. However, significantly lower hardness was recorded in fish harvested using the electric stunner, compared to the fish killed with slurry ice of the same harvesting period. Shelf life ranged between 13-18 days for gilthead seabream, 10-16 days for European sea bass and 10-14 days for red sea bream, depending on harvesting period. K E Y W O R D Sfish welfare, harvest, quality, shelf life, stress, water temperature | 2609 PAPAHARISIS et Al.

Linking stocking densities and feeding strategies with social and individual stress responses on gilthead seabream (Sparus aurata)

“…Regarding cortisol levels, no significant differences were found between individual traits, though proactive fish presented lower levels in LD and higher levels in HD conditions compared to reactive fish. In the present study cortisol levels were high under all circumstances when compared with some previously published work (Papaharisis et al 2019), and this can be due to either the stress of fishing since fish were sedated outside the holding RAS or alternatively due to the experimental design itself. Carbonara et al (2019) published a study where bigger seabream was grown in different stocking densities and obtained similar levels of cortisol.…”

Twenty Years of Research in Seabass and Seabream Welfare during Slaughter

“…Some electric stunning trials have also yielded promising results in seabream and sea-bass [ 31 , 34 , 36 , 48 , 49 , 50 ]. Following the application of an electric current, the fish are transferred to a tank filled with ice slurry for slaughter.…”

“…Even the stocking density and time spent in confinement prior to harvesting are factors to consider [ 53 ]. Thus, there were no differences in mean plasma cortisol, glucose, or lactate concentrations in seabream after electrical stunning followed by immersion in ice slurry or ice slurry alone [ 50 ]. Cortisol and lactate levels were higher in seabass stunned by electricity than in those immersed in ice slurry [ 54 ].…”

“…Electrical stunning has been found to have a lower hardness than ice slurry in studies of seabass flesh texture variations [ 50 ]. The addition of clove oil to the rearing tank reduced pre-slaughter harvesting stress in seabream, but the hardness of the fillet, both raw and cooked, did not differ significantly from the stress condition caused by harvest net crowding [ 59 ].…”

Influence of bleeding on myoglobin and meat quality changes of Channel catfish muscle during freeze‐thaw cycles

“…Many factors affect the frozen quality, such as slaughter method, reducing bacteria treatment, conditioning treatment, storage temperature, and packaging (Papaharisis et al, 2019). The color, myoglobin, and meat qualities of fish are affected by different slaughter methods .…”