Changes of rheological behavior, thermal and microstructural properties of myofibrillar protein-κ-carrageenan mixed sol as mediated by NaCl concentration

The present study was aimed to investigate the effect of κ-carrageenan (KC) addition with different levels (0.1, 0.2, 0.3, and 0.4%, w/w) on the rheological behavior, thermal properties, and microstructure of myofibrillar protein (MP) sol as mediated by NaCl concentration (0.3 and 0.6 M). The rheological behavior revealed that the incorporation of KC enhanced the interaction between KC and MP, leading to a firmer and tighter intermolecular gel-like network structure of the sample. Moreover, the existence of KC positively enhanced the enthalpy values of MP-KC mixed sols, as well as promoted the formation of larger aggregates, which were mainly ascribed to the hydrophobic interactions and hydrogen bonds between MP and KC. In addition, 0.6 M NaCl concentration rendered relatively higher rheological behaviour, enthalpy values, α-helix contents, and smaller aggregates of MP-KC mixed sols (P < 0.05) than those with lower NaCl concentration (0.3 M). Our present results provided a thorough understanding for the interactions between MP and KC, which promoted the development and design of MP-KC based products with desirable attributes.