Kouichi Hosoya, Motokazu Nakayama, Daisuke Tomiyama, Tetsuhiro Matsuzawa, Yumi Imanishi, Seiichi Ueda, Takashi Yaguchi
Global R&D-Safety Science, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-Gun, Tochigi 321-3497, Japan.
Recently the numbers of spoilage incidents in food industry by the species of Thermoascus are increasing, but the risk of food spoilage have never been evaluated.
It became obvious that their heat-resistances were higher than those of other heat-resist fungi, Byssochlamys, Hamigera and Neosartorya by our analyses. On the other hand, Thermoascus aurantiacus and Byssochlamys verrucosa had the idh gene, but they showed no patulin production in Potato dextrose broth or Czapek-glucose medium. Therefore, Thermoascus must be discriminated from other fungi in the food industry. We developed a rapid and highly-sensitive method of detecting Thermoascus in the genus level by using PCR. This method is expected to be extremely beneficial for the surveillance of raw materials in the food production process.