Influence of Rosmarinic Acid on Biochemical and Structural Properties of Silver Carp Myofibrillar Protein under MetHemoglobin Catalyzed Docosahexaenoic Acid Oxidative Stress

This paper aimed to investigate the effect of rosmarinic acid (RA; 10, 75, 250 µmol/g protein) addition on silver carp myofibrillar protein (MP) oxidation under MetHemoglobin (MetHb) catalyzed docosahexaenoic acid (DHA) oxidative stress. The changes in lipid and protein oxidation and structural stability were evaluated by spectroscopic methods. The results suggested that all the doses of rosmarinic acid inhibited the peroxide value (PV) and thiobarbituric acid reactive species (TBARS) formation in oxidized MP. The findings also indicated that low and medium doses of rosmarinic acid prevented the carbonyl formation, loss of total -SH groups, and free amines in oxidized MP. However, the high dose of RA could not prevent the MP oxidation and acted as pro-oxidant. In addition, rosmarinic acid affected the myofibrillar protein structure, as exhibited by the unfolding. Furthermore, the microstructure results showed the hydrophobic interaction between oxidized MP and rosmarinic acid possibly by adduct formation and aggregation of MP with increasing concentration of rosmarinic acid.