Attributes of lipid oxidation due to bovine myoglobin, hemoglobin and hemolysate

• One high molecular weight protein was detected during the purification of bovine hemolysate by size exclusion chromatography.
• Bovine oxyhemoglobin promoted lipid oxidation in washed muscle more effectively compared to oxymyoglobin.
• The hemin release from methemoglobin contributed to the greater ability of oxyhemoglobin to promote lipid oxidation.
• Hemoglobin mediated lipid oxidation much faster at a lower pH.

Bovine hemolysate was purified by size exclusion chromatography, and one high molecular weight protein was detected relative to the hemoglobin (Hb) fraction. Purified Hb promoted lipid oxidation in washed muscle slightly but significantly better than hemolysate, which may have been due to the absence of catalase and peroxiredoxin in the purified Hb. Purified Hb auto-oxidized to metHb more rapidly than Hb in the hemolysate (P < 0.05). OxyHb promoted lipid oxidation in washed muscle more effectively compared to oxyMb (P < 0.05). This was ascribed to hemin, released from metHb, promoting lipid oxidation more readily than oxidative forms of Mb that retain their protoporphyrin moiety. A 3:1 ratio of Mb:Hb promoted lipid oxidation similarly compared to adding a 1:1 ratio of Mb:Hb to washed muscle. Lipid oxidation products due to Hb-mediated lipid oxidation were elevated 60-fold at pH 6.3 compared to pH 6.7.