Abstract
The variations of the tensile strength of myosin gel during heating were measured based on an equation, which was derived from the thermodynamics of elastic deformation, in orderto clarify the mechanism of the elasticity of kamaboko. Myosin was extracted from the croaker Nibea mitsukurii, and 85mg protein/g gel/0.6M KCl was prepared by heating at 80°C for 20min. The myosin gel was extended to twice its original length, and successively heated by an electric heater alone or in combination with an infrared ray. A commercially available kamaboko and a rubber band were also submitted to the experiments to compare with the myosin gel. The tensile strength of both myosin gel and kamaboko increased and immediately decreased when these gels were heated by the electric heater and it continuously decreased with heating by an infrared bulb. In the case of rubber, on the other hand, the tensile strength increased continuously. From the results of myosin gel and kamaboko, the entropy of these gels was found to increase with elongation under a constant temperature. Hence, both myosin gel and kamaboko were found to have another mechanism for elasticity, different from that of rubber, or entropy elasticity. As a result, myosin gel was concluded to be an energy elastic body, not an entropy one.
