Influence of temperature, moisture, and propionic acid on mold growth and toxin production on corn

The influence of temperature and propionic acid on mold growth and toxin production on whole corn with 10, 15, or 20% added water was studied. Levels of propionic acid tested at each moisture level were 0, .025, .05, and .1%. Each flask of corn was inoculated with spores of a citrinin-producing Penicillium spp. and was then incubated for 8 weeks at a constant temperature of 5 C, at 5 C at night and room temperature during the day, or at room temperature both at night and during the day. The corn was then dried, ground, and fed to chicks to determine the presence of citrinin. Regardless of acid level or moisture content, neither mold growth nor toxin production occurred on the corn incubated at 5 C. Both mold growth and toxin production occurred on corn either partially or totally incubated at room temperature but were more prevalent in the latter. Increasing the moisture content resulted in greater mold growth and toxin production, especially on the corn incubated at room temperature. Higher levels of propionic acid were needed to prevent mold growth and toxin production as the moisture content of the corn increased.