Preservation of High-Moisture Corn: A Microbiological Evaluation

Ammonia, ammonium isobutyrate, isobutyric acid, and propionic-aeetic acid at concentrations of .5%, 1.75%, 1.5%, and 1.2%, respectively, were applied to comparable 52.8 m 3 lots of freshly harvested yellow dent corn having a moisture content of 27%. Treated corn was stored in partially open wooden bins. Harvestore~ and barrell storage of untreated corn were included as controls. Temperature and microbiological changes were evaluated tba'oughout 6 mo of storage. As the corn came from the field, log counts of 6.3, 5.8, 5.3, and 3.0 per g were determined for bacteria, molds, yeasts, and actinomycetes, respectively. All chemicals immediately reduced bacterial and actinomycete counts and eliminated molds and yeasts. All treatments after approximately 30 days" storage had secondary fungal growth. Seopulariopsis brevicaulis predominated on ammoniatreated corn; Mueorales, and species of Monascus, Penicillium, Fusarium, and Aspergillus flares, as well as A. fumigatus, were in ammonium isobutyratetreated corn. A. flavus was the predominant mold infecting isobutyrie acid and propionic-acetic acid treated corn late in storage.