Influence of carbon monoxide on the colour stability of defrosted yellowfin tuna (Thunnus albacares) muscle stored under aerobic and anaerobic conditions

BACKGROUND: The use of carbon monoxide (CO) and various packaging types has been suggested to improve/stabilise the colour and oxidative processes of red meats, thereby improving the retail value and revenue. The main aim of this study was to investigate the influence of packaging type and CO treatment on the colour and oxidative stability of tuna. RESULTS: The addition of CO significantly increased the redness (a^*) of the tuna steaks but the redness was not equally stable for all treatments. The aerobically packaged steaks showed a temporal decrease in redness while the redness of anaerobically packaged steaks remained relatively stable. The addition of CO did not significantly affect (P >0.05) the brownness (b^*) (with one exception) and lightness (L^*) of the steaks. The anaerobically packaged steaks showed a significant difference (P <0.05) in the b^* values. No significant differences (P >0.05) in lipid or protein oxidation were observed between treatments. The aerobically packaged steaks had a significant temporal increase (P <0.05) in lipid oxidation while no such trend was apparent in the anaerobically packaged steaks. Protein oxidation remained relatively stable over time for both aerobically and anaerobically packaged steaks. CONCLUSION: Storing CO treated tuna steaks in anaerobic packaging can improve the oxidative and colour stability of tuna. Such treatment can reduce spoilage and wastage thereby potentially increasing revenue.