COMPOSITIONAL CHANGES IN SURFACE MYCOFLORA DURING RIPENING OF NATURALLY FERMENTED SAUSAGES

Changes in the composition of the surface mycoflora during ripening of naturally fermented sausages were examined. The samples were collecte d from small-scale production plants in Northern Italy. In the first p art of the ripening process yeast dominated the mycoflora and constitu ted more than 95% (colony forming units [CFU]). After 2 weeks' ripenin g, yeast and molds were present in equal quantities. The molds continu ed to increase in numbers and at the end of processing the result was a more than 95% dominance. The genus Penicillium dominated the mycoflo ra at the end of the ripening process. Penicillium nalgiovense, a spec ies frequently used as a starter culture, constituted 50% of the molds and was found to occur naturally in the environment. Four species, Pe nicillium olsonii, Penicillium spathulatum, Penicillium oxalicum and P enicillium capsulatum, that have not been isolated from this environme nt before constituted, respectively 15%, 5%, 3%, and about 1% of the m ycoflora. Also, Penicillium species that are known as potential produc ers of mycotoxins were isolated; e.g., Penicillium verrucosum and Peni cillium commune constituted 5 and 3% of the mycoflora. It was shown th at six out of nine isolates of P. verrucosum produced ochratoxin A and one isolate produced citrinin. One isolate of P. commune was examined and shown to produce cyclopiazonic acid. A large number, 53, of Penic illium nalgiovense isolates were examined, but no known mycotoxins wer e shown to be produced after growth on synthetic agar media.