Synergistic antifungal effects of the preservative ammonium propionate and medium chain fatty acids against dormant and germinating conidia, germ tubes and hyphae of Aspergillus chevalieri, a feed spoilage fungus.

In feed, propionic acid is the weak organic acid of choice to prevent growth of spoilage fungi. For safe and easy industrial handling this antifungal agent is applied in the presence of neutralizing ammonium, which however has the disadvantage to negatively affect the efficacy of fungus-inhibiting properties of the formulation. In the present study we investigated the impact of medium chain fatty acids (MCFA) on the antifungal efficacy of an ammonium propionate formulation on dormant- and germinating conidia as well as germ tubes and hyphae of Aspergillus chevalieri, a xerophilic fungus predominant on moulded feed.