In our previous paper, high pressure (HP) of 200 MPa on water-soaked soybean resulted in
accumulation of GABA and other free amino acids, due to proteolysis utilizing internal enzymes [1]. In
the pressure range of approximately 200 to 400 MPa, certain enzymes in an agroproduct would be active
[2], but the internal structure was partially damaged [3]. Therefore, if HP would confer suitable
conditions for a certain biochemical reaction to the inside of an agroproduct, the agroproduct could
behave a bioreactor [4].
In this study, we applied HP on water-soaked soybean and Glu-soaked soybean seeds as a cellular
biological material, and investigate the effects of HP on bioconversion of Glu to GABA catalysed by
glutamate decarboxylase (GAD) from the viewpoints of the cell structure and enzymatic reaction system.