Flavor production from a non-stick oil by moulds

Natural flavor was accidentally produced from rice cake products in Japan. A non-stick oil had been sprayed on the products during the production process. It was found that a Penicillium corylophilum strain, a contaminant of the oil, produced the flavor from the oil. The ingredients of the flavor were four volatile substances, 2-heptanone, 2-nonanone, 2-heptanol, and 2-nonanol. Challenge tests with the mould strain in a rice cake system were performed under various conditions. The volatile substances were produced in the largest amounts at 25 degrees C, followed by 20 or 30 degrees C then 10 degrees C. 2-Heptanone was produced most remarkably at 25 degrees C, followed by 2-nonanone, 2-heptanol, and 2-nonanol. The growth patterns of the mould were similar between 20-30 degrees C, and the growth at 10 degrees C was delayed. The non-stick oil itself had neither flavor nor volatile substance. The flavor was also produced from coconut oil, which was one of the materials of the non-stick oil. No bacteria or yeasts tested produced any flavor from the non-stick oil, whereas most of the moulds tested produced flavor components.