Flavour formation from hydrolysis of pork meat protein extract by the protease from Staphylococcus carnosus isolated from Harbin dry sausage

Abstract

The impact of the protease from Staphylococcus carnosus on the structural characteristics, hydrolysis and flavour development of pork myofibrillar protein (MP) and sarcoplasmic protein (SP) were assessed. Hydrolysis altered the surface hydrophobicity and secondary structure of MP and SP, as measured by surface hydrophobicity, intrinsic fluorescence and Fourier transform infrared spectra. Atomic force microscopy and automated amino acid analysis revealed that the S. carnosus protease degraded the native proteins into low-molecular-weight hydrolysates with uniform distribution and free amino acids, especially glutamic and glycine acid. Moreover, the hydrolysis of MP and SP by the protease promoted the production of volatile compounds, such as aldehydes, alcohols, acids and esters. Molecular docking revealed the binding sites and the major interaction forces (hydrogen bonding) between actin and the protease. The molecular dynamics analysis showed that the binding process of the protease to actin induced a conformational change in actin. In summary, the potential application value of the S. carnosus protease in improving the flavour of Harbin dry sausage is suggested.