Biotinylated caffeic acid covalent binding with myofibrillar proteins in alkaline conditions: Identification of protein-phenol adducts and alterations in protein properties

In this study, the effects of covalent interactions between myofibrillar proteins (MP) and caffeic acid (CA) were investigated. Protein-phenol adducts were identified by biotinylated caffeic acid (BioC) used as a substitution of CA. The total sulfhydryls and free amines content were decreased (p < 0.05). The alpha-helix structure of MP increased (p < 0.05) and MP gel properties enhanced slightly at low dosages of CA (10 and 50 mu M), and both were impaired significantly (p < 0.05) at high dosages of CA (250 and 1250 mu M). Two prominent adducts of myosin heavy chain (MHC)-BioC and Actin-BioC were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), which gradually increased at low concentrations of BioC (10 and 50 mu M), and raised significantly at the concentration of 1250 mu M. According to the correlation analysis, MHC-BioC and Actin-BioC adducts showed a significant negative correlation with gel properties, such as G', hardness, and water holding capacity (WHC) (p < 0.01), which indicated that the covalent interactions between MP and CA significantly affected the quality of meat products.

Automated summary

The study investigated the effects of covalent interactions between myofibrillar proteins (MP) and caffeic acid (CA). Protein-phenol adducts were identified using biotinylated caffeic acid (BioC) as a substitute for CA. The total sulfhydryls and free amines content decreased, while the alpha-helix structure of MP increased. MP gel properties slightly enhanced at low CA dosages, but significantly impaired at high CA dosages. Myosin heavy chain (MHC)-BioC and Actin-BioC adducts were identified and their concentrations showed a negative correlation with gel properties.