Stress Relaxation of Noodle

Abstract

To clarify the rheological properties of Japanese type noodle, the stress relaxation under a well-defined normal strain was measured by the floating method using a mercury bath. The raw noodle showed a nonlinear viscoelasticity, while the cooked noodle can be expressed by a linearity up to 6% in strain. The relaxation modulus of both raw and cooked noodle indicated a minimum value at 1% NaCl, and then increased with increasing NaCl content. The relaxation modulus of the cooked noodle gave maximum value at 4% NaCl, and decreased slightly with increasing NaCl content. The relaxation modulus of both raw and cooked noodle decreased, while water content increased. The effect of added water for cooked noodle was smaller than that for raw noodle. The time-temperature superposition principle was found in the master relaxation curve existing in the temperature range of 10-40°C for raw noodle and in the range of 5-50°C for cooked noodle. Sixty seven and 117KJ/mol of apparent activated energy was evaluated from the correlation between the shift factor and 1/T for the raw noodle and the cooked noodle, respectively. Relaxation time distributed in a wide range of 1-10⁴ sec for the raw noodle and 0.1-10⁵ sec for the cooked noodle.