Protease Activity and Gel-forming Ability of Ginger Rhizome Juice

The ginger rhizome has been known to contain proteolytic enzymes. In this study, we evaluated the protease activities in juice extracted from ginger rhizomes. The specific protease activity in juice from ginger ripened after harvesting was higher than that of ginger that was not ripened after harvesting. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis indicated that the ginger rhizome juice displaying high specific protease activity contained a 30 kDa protein. This juice was also observed to have milk gel-forming ability.