Shock treatment for Japanese radish, and comparison of hardness alteration and needed time for boiling until edible

Abstract

When shock wave which is propagating material reaches to other material which has difference density, reflected wave, transmission wave, and rarefaction wave occurred at density interface due to difference in density between two materials. At this time, tensile force is generated at interface, and destruction and deformation of material are caused. The research about shock treatment for foods using this phenomenon is conducted at our laboratory. In this paper, Japanese radish is used as one of food samples, and this sample is treated by underwater shock wave due to explosion of explosive. Many Japanese eat Japanese radish as pickles or cooked food. It needs a long cooking time for making pickles or boiling of Japanese radish. The aim of this research is to decrease boiling time, and to increase permeability of seasoning liquid by treatment of underwater shock wave. Before and after shock treatment, hardness of Japanese radish is measured. After boiling, hardness of Japanese radish is also measured using Durometer. And these results were compared. Moreover, colored water and Japanese radish were put in a same bottle, then was treated by underwater shock wave. The degree of permeance of colored water for Japanese radish was also compared.