Abstract
A xerophilic fungi (KIH CO214), isolated from a spoilage outbreak involving importedAustrian chocolate from Austria, was identified asChrysosporium farinicola(Deuteromycota).This was the first time this fungus isolated in Japan. This fungus grew well and produced large numbers of conidia on MY5OG agar (Aw0.897), and the colony formed on common media was white and powdery. The teleomorph of this fungus was not seen on 5 selected media including natural substrates. The optimal growth of this fungus was obtained at 30°C, the minimum accorded at 15°C and the maximum at nearly 37°C . The fungus could grow at a pH range of 3-9.As a result of heat inactivation treatment, the lethal thermal point for this fungus was shown as 5 min at 65°C. Thus, an inactivation temperature of more than 70°C proved to be most practical. As an inoculation test on sterilized chocolate samples which were adjusted to water activity conditions from Aw 0.901 to Aw 0.752, mycelial growth of this fungus was found on all substrates after 1month at 25°C. For a comparison, 9 xerophilic fungi were also used in the above physiological experiments.
