CHANGES OF RHEOLOGICAL PROPERTIES OF CUTTLEFISH AND SQUID MEAT BY HEAT-TREATMENT

The changes of theological properties of a cuttlefish and four squids by heat treatment were studied by the differential scanning calorimetr y (DSC), the rupture test, and the stress relaxation test. The thermog rams of raw ''ika'' mantle meat showed three major endothermic peaks a t 50 degrees C, 57 degrees C, and 74 degrees C. The first and second p eaks mainly corresponded with the denaturation of myosin and collagen. The third peak was that of actin which was almost native up to 63 deg rees C, while the other proteins had been completely denatured below 6 3 degrees C. The thermograms for all samples indicated that the denatu ration of mantle meat had been completed up to 80 degrees-C. Then, the theological properties were measured for raw meat and heated meat at 63 degrees C or 80 degrees C. A positive correlation between the conte nt of crude protein and the instantaneous elastic modulus was only fou nd in heated meat at 63 degrees C. It is considered that this relation ship was associated with the amount of remaining native actin.