Effects of ferulic acid on the oxidation stability and nitrozation of myofibrillar proteins under oxidative stress
Ruxia Gu, Feng Li, Dapeng Li, Feng-Qin Ge, Longhua Xu, Yongli Wang
Abstract
This study investigated the effects of ferulic acid (FA) on the oxidative stability and nitrozation of porcine myofibrillar proteins (MPs) under oxidative stress. The addition of FA significantly (P < 0.05) inhibited the formation of carbonyl and dityrosine, and reduced the sulfhydryl and free amine content compared with the oxidized MPs. Moreover, FA intensified oxidation-initiated loss of surface hydrophobicity and α-helix conformation, and enhanced protein cross-linking. A progressive quenching of MP endogenous fluorescence intensity was observed with the increase of FA concentration, and the emission wavelength showed a slight red shift. Beside, the addition of FA significantly eliminated sodium nitrite and almost completely inhibited the formation of 3-nitrotyrosine (3-NT) and N-nitrosodimethylamine (NDMA) at 200 μmol/g. Principal component analysis indicated that there were positive correlations between protein oxidation variables (carbonyl, dityrosine and surface hydrophobicity) and nitrozation indexes (3-NT and NDMA), as well as between 3-NT and NDMA. These results suggest that FA could suppress the nitration via controlling MP's oxidation.