Fungal growth and the presence of sterigmatocystin in hard cheese.

Molds isolated from visibly molded cheeses in shops, households, and warehouses have been identified. Mold flora of cheeses in shops and households consisted mainly of Penicillium verrucosum var. cyclopium. On cheeses ripening in warehouses, Penicillium verrucosum var. cyclopium, Aspergillus versicolor, Aspergillus repens, and Enicillium verrucosum var. verrucosum were the dominant mold species. Cheese ripening in warehouses and molded with A. versicolor were examined for sterigmatocystin. Nine of 39 cheese samples contained sterigmatocystin in the surface layer in concentrations ranging from 5 to 600 micrograms/kg.