肉品色泽与肌红蛋白（Mb）形态密切相关。申请者前期研究不同形态Mb（氧合肌红蛋白、高铁肌红蛋白）与磷脂氧化的关系时发现，在肉品贮藏和加工中普遍存在血红素辅基（Heme/Hemin）从Mb中脱落的现象，不仅引起肉品变色，而且导致脂质氧化加速，但目前有关辅基的脱落机制未见报道。本项目首先制备不同形态Mb，建立辅基脱落的水相反应体系；采用电化学生物传感器和蛋白质印迹法测定蛋白含量，圆二色谱等测定蛋白结构，核磁共振、拉曼光谱等确定辅基脱落位点，跟踪水相反应体系中不同因素对Mb和辅基的影响，建立辅基脱落过程的动态模型；并通过肌肉内环境的验证实验，最终确定辅基脱落位点、效价比、途径，解析辅基脱落机制。本项目研究成果为肉品色泽、脂质氧化等品质调控，以及新型、高效、安全发色剂的研发提供新思路和理论支撑，具有重要的科学意义和应用前景。

Color of muscular tissues is correlated with the form of myoglobin (Mb). The applicant’s previous studies showed lipid oxidation was highly linked to the conversions of different types of Mb (OxyMb and MetMb). During processing and storage of meat, the detachment of Heme/Hemin prosthetic group from Mb is a common phenomenon, which leads to discoloration of meat and accelerates lipid oxidation. However, the detachment mechanism of Heme/Hemin prosthetic group from Mb remains largely unknown. In the present project, different forms of Mb will be prepared, and aqueous reaction systems will be established to explore the detachment mechanism. Mb will be quantified with the electrochemical biosensor and Western blot. Changes in Mb conformation will be evaluated by circular dichroism spectra (CD), and the specific detachment sites in Mb for Heme/Hemin prosthetic group will be identified with the aid of nuclear magnetic resonance (NMR), fluorescence spectrum and Raman spectroscopy. Changes in Mb and Heme/Hemin prosthetic group will be tracked under variable conditions and the dynamic model of detachment process will be built. The detachment of Heme/Hemin prosthetic group from Mb will be further validated in the intramuscular environment. The mechanism will be confirmed in view of the detachment sites, detachment coefficient and pathway. The result will provide a theoretical basis for the regulation of meat color and lipid oxidation, and an idea for the development of a new and safe meat colorant.