Haemoglobin-mediated lipid oxidation in washed chicken mince

Background/Objectives: Loss in quality of chicken meat caused by lipid oxidation mediated by haemoglobin can lead to the rejection. The study aimed to study lipid oxidation and colour of washed chicken as affected by different haemoglobins. Methods/Statistical Analysis: Different forms of haemoglobin from chicken blood including Oxyhaemoglobin (OxyHb) and Methaemoglobin (MetHb) were prepared and added into washed chicken mince to obtain the final concentration of 8 μmole Hb/kg washed mince. Lipid oxidation products, volatile compounds and color in chicken mince samples were monitored during 8 days of the refrigerated storage. Findings: Washed chicken mince added with oxyHb and metHb contained the higher Peroxide Value (PV) and Thiobarbituric Acid-Reactive Substances (TBARS), compared with the control (P<0.05). Oxy-form was more pro-oxidative than met-form as evidenced by the higher PV and TBARS (P<0.05). Volatile lipid oxidation compounds, especially hexanal, were formed at higher rate in the sample added with oxyHb, compared with the control and that added with MetHb. At day 0 of storage, the sample added with oxyHb showed the higher a*-value but lower L* and b* value when compared with the control sample. The decrease in a* value was more pronounced in the sample containing oxyHb at day 8 of refrigerated storage. Thus, lipid oxidation and colour of chicken mince were more likely governed by the form of haemoglobin. Applications/Improvements: Bleeding should be carried out effectively during slaughtering process to prevent the lipid oxidation and discoloration of chicken meat.