Abstract
Dried shiitake mushrooms were rehydrated with ultrasonic-irradiation in search for rational rehydration methods. Its effects on the texture properties and the preference test were studied. The following results were obtained; water absorption by the shiitake mushrooms, the color of yellowing of the rehydration liquid and its browning were greater with ultrasonic-irradiation than in the control without the irradiation. The irradiated shiitake mushrooms had less hardness and gumminess and were softer. Irradiation time was 20 min and total immersion time was 2 h for Jyodonko and 1 h for Jyokoshin at 5°C and 25°C which are within a suitable rehydration range. Under these conditions, water absorption reached 90% of the maximum and the shiitake mushrooms scored high preference points in such properties as softness and gumminess. Irradiation slightly affected on the content of RNA and the composition of 5'-GMP, 5'-AMP, 5'-UMP, 5'-CMP and free amino acids in steam-cooked shiitake mushrooms.
