Abstract: To evaluate the effect of atmospheric pressure plasma jet (APPJ) on the structure and rheological properties of chicken myofibrillar proteins (MP), MP samples were treated by APPJ for different durations (0, 10, 20, 30 and 40 s) and then measured for their pH, turbidity, particle size, solubility, protein composition, structural and rheological properties. The results showed that as APPJ treatment time prolonged, the pH and solubility of MP were gradually decreased, and the turbidity and particle size were significantly increased (P < 0.05). APPJ treatment increased the storage modulus (G’) and loss modulus (G’’) at each elevated temperature and angular frequency. Reduced and non-reduced sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the composition and molecular mass of MP were not changed. In addition, the total content of disordered secondary structures (β-turn and random coil) in MP were increased, while the total content of ordered secondary structures (α-helix and β-sheet) were reduced. The tertiary and quaternary structures of MP were also changed by APPJ. The surface hydrophobicity was increased, and the content of free sulfhydryl groups was increased firstly and then decreased. In summary, APPJ can modify the physicochemical properties and structure of chicken MP, and improve the rheological properties, thereby affecting MP function and muscle quality.

Key words: atmospheric pressure plasma jet; chicken; myofibrillar protein; structure; rheological properties