Change of Various Enzyme Activities of Koji and Sterilization of Koji by γ-Radiation

Abstract

Sterilization and changes of various enzyme activities of koji by gamma irradiation were investigated. A dose of 1 Mrad gamma irradiation was effective for the sterilization of koji. Various enzymes of koji were inactivated about 10-30% by the irradiation, while no influence, was observed for shochu fermentation. There seemed to be no influence for qualities of sake and shochu by the irradiation.