Mould contaminants on Jarlsberg and Norvegia cheese blocks from four factories

Visible mould from 225 blocks of the Norwegian semi-hard cheeses Jarlsberg and Norvegia from four factories were subcultured and identified. Altogethe r 23 different fungal species were detected. The two most important contami nating species were Penicilli. um commune and P. palitans, constituting 21. 4% and 17.9% of the total isolates, respectively. The other dominating cont aminants were P. roqueforit spp. roqueforti, Geotrichum candidum, P. solitu m and P. crustosum. These species, together with P. commune and P. palitans , represented 80.9% of the total isolates. P. commune, P. palitans, P. roqu eforti spp. roqueforti and P. solitum were most common contaminants on chee se produced in all four factories, while G. candidum was found to be import ant on Jarlsberg cheese from only one factory. P. crustosum was one of the dominating species on Norvegia cheese. (C) 2001 Elsevier Science B.V. All r ights reserved.