Effect of two stunning methods on postmortem muscle pH and meat quality of common carp (Cyprinus carpio L.)

Percussive and electrical stunning are the most promising methods in terms of rendering fish unconscious prior to slaughter. The aim of this study was to determine the effect of these two stunning methods on postmortem muscle changes and meat quality of common carps. The experimental fish were stunned either by percussion (Group 1) or by electrical current application (Group 2), both followed by immediate decapitation. Muscle pH was measured at different time intervals to assess the postmortem metabolic changes, whereas meat colour, drip loss and water activity were used as quality parameters. The fish in Group 1 showed slightly accelerated postmortem muscle metabolism, higher redness (a*) and yellowness (b*) colour values and lower water activity. Percentage of drip loss after 4 days of storage at 4 °C did not differ significantly between the two groups. Based on the obtained results we concluded that both tested stunning methods were not associated with high levels of stress and significant detrimental effect on the meat quality of common carps.