Abstract:
To improve the flesh quality of tilapia, we studied the effects on flesh quality of tilapia by different slaughter methods. Tilapia were slaughtered by four different methods as follow: (Ⅰ) bleeding followed by immersion in ice/water slurry for 20 minutes, (Ⅱ) immersion in ice/water slurry for 20 minutes, (Ⅲ) percussive stunning, (Ⅳ) percussive stunning followed by bleeding and immersion in water for 20 minutes. TVB-N values, Ca
2+-ATPase activity, color and texture profile analysis (TPA) were measured during iced storage. The results show that TVB-N values of four groups increase signally, and Ca
2+-ATPase activities of four groups decrease obviously during iced storage. TVB-N values in group Ⅱand Ⅲ are significantly lower than that in group Ⅰ and Ⅳ. Group Ⅱand Ⅲ are benefit for retaining freshness during iced storage, while group Ⅲ and Ⅳ are conducive to maintaining Ca
2+-ATPase activity. Fillets of group Ⅱand Ⅲ become paler than that of group Ⅱand Ⅲ, and fillets of group Ⅱand Ⅲ have higher redness than groupⅠand Ⅳ. Hardness, chewiness and gumminess in fillets of four groups decreased significantly during iced storage. Texture quality in group Ⅲ maintains better than that in other groups. In conclusion, percussive stunning is the optimum to kill tilapia in the four methods.