Risk analysis and rapid detection of the genus Thermoascus, food spoilage fungi

- The heat-resistance of strains Thermoascus spp. was higher than those of other heat-resist fungi.
- Thermoascus aurantiacus had the idh gene, but it showed no patulin production in Potato dextrose broth or Czapek-glucose medium.
- We developed a rapid and highly-sensitive method of detecting Thermoascus at the generic level by using PCR.

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.