Structural basis for high-intensity ultrasound treatment in the rheology of myofibrillar protein extracted from White Croaker in relation to their solubility

Abstract

This study was focused on evaluating and performing correlation analysis between the solubility, rheological property, and structural changes of MP (Myofibrillar Protein). The MP was extracted from White Croaker and altered using high-intensity ultrasound treatment (HIUT) (frequency, 20 kHz; power, 500 W; pulse, 3 s on and 3 s off) at different times (0, 2, 4, 6, 8 & 10 min). After 10 min of HIUT, the solubility and fluidity of MPs were enhanced. The HIUT could break the MP aggregates and induce myosin heavy chain (MHC) degradation. Further, HIUT disordered and unfolded MP, induced migrations of surface charge groups, especially the negative charge groups. It also increased the exposure of more charged groups and active chromogenic group residues. The Correlation analysis and Principal Component Analysis (PCA) exhibited a high correlation between the solubility, the zero shear viscosity of MP, and its indexes of structural changes after the HIUT. Our work can provide useful knowledge for the modification of fish MP.