Changes of rheological properties of cuttlefish and squid meat by heat treatment

The changes of rheological properties of a cuttlefish and four squids by heat treatment were studied by the differential scanning calorimetry (DSC), the rupture test, and the stress relaxation test. The thermograms of raw "ika" mantle meat showed three major endothermic peaks at 50 degree C, 57 degree C, and 74 degree C. The first and second peaks mainly corresponded with the denaturation of myosin and collagen. The third peak was that of actin which was almost native up to 63 degree C, while the other proteins had been completely denatured below 63 degree C. The thermograms for all samples indicated that the denaturation of mantle meat had been completed up to 80 degree C. Then, the rheological properties were measured for raw meat and heated meat at 63 degree C or 80 degree C. A positive correlation between the content of crude protein and the instantaneous elastic modulus was only found in heated meat at 63 degree C. It is considered that this relationship was associated with the amount of remaining native actin.