Quality consequences of bleeding fish after capture

Summary

A major cause of downgrading and rejection of fish in the white fish industry is due to discoloration of the fillets because of poor exsanguination. Thus, different bleeding methods and the time elapse between capture and bleeding were evaluated to assess whether different bleeding procedures influences the fillet colour of Atlantic cod (Gadus morhua). Visual assessment of the fillet quality and an instrumental method were both used to determine the effects of various bleeding methods on blood residuals and fillet colour. Both the bleeding method and the time elapse (0, 30, 60, 180 min) prior to bleeding influenced the exsanguination. Thus, bleeding reduced the blood residuals and improved the fillet whiteness. However, no clear trends between various methods of bleeding were observed. Compared to direct gutting immediately after capture, better exsanguination (P < 0.05) was obtained when the cod was bled immediately and exsanguinated for 30 min prior to gutting (a two-stage method). However, no clear trends between various methods of bleeding were observed. Generally, the time spent from catch to bleeding was the single most important factor influencing proper exsanguination. The results conclude that Atlantic cod should be bled within 30 min after death. When the fish were bled 3 h after death, it was found to be similar to unbled fish in terms of flesh colour.