The effect of slaughtering methods on actin degradation and on muscle quality attributes of farmed European sea bass ( Dicentrarchus labrax )

In the current study, two different slaughtering procedures, spiking vs immersion in water/ice slurry, were applied on electrically stunned European sea bass (Dicentrarchus labrax) and the effects on actin degradation and fillet quality attributes were investigated. Rigor mortis index was similar for the two slaughtering techniques, whereas the shear force measurement indicated that rigor mortis occurred more quickly and intensely in the water/ice handled fish than in those slaughtered by spiking. The water/ice immersion procedure also resulted in higher amount of actin fragments than spiking. Muscle tissue apparent viscosity and water holding capacity were lower in sea bass treated in water/ice slurry compared with fish handled by spiking, whereas the acidification patterns of the two groups were not easily distinguishable. In conclusion, spiking appeared to preserve actin integrity better that water/ice and it seemed to ensure less muscle damage as indicated by the higher viscosity and water holding capacity values. Finally, a role of actin as a biochemical marker for the prediction of fish quality was suggested.