Koji preparation Red koji (M. anka) and white koji (A. kawachii) were processed
under controlled temperature and humidity. In brief, rice was soaked in water for 1 h, and
excess liquid was drained off for 1 h. The rice was then steamed for 1 h, and the steamed rice was cooled to 30 °C before inoculation with the conidia in a safety cabinet. The
inoculated rice was transferred to a sterile glass petri dish (diameter, 21 cm) and
maintained at 35 °C