2013 Volume 19 Issue 6 Pages 1051-1059
The effect of frozen storage at −20°C and −50°C on the structure of myofibrillar proteins (MP) from silver carp was determined using several analytical methods. Differential scanning calorimetry thermograms demonstrated that the thermal stability of MP decreased and some structural changes occurred particularly in the rod-like tail portion of myosin. The trend of surface hydrophobicity was first an increase and then a decrease, indicating that the unfolding of protein molecules and exposure of buried hydrophobic residues occurred firstly, followed by the aggregation of MP through hydrophobic interactions, and this was also supported by intrinsic fluorescence and Raman. Circular dichroism and Raman data indicated that there was a decrease in α-helix content with a concomitant increase in β-sheet during storage. All the experimental data confirmed that the MP stored at −20°C suffered more pronounced structural alteration than those stored at −50°C.
