Microbial composition of defect smear – A problem evolving during foil-prepacked storage of red-smear cheeses

To elucidate the problem of smear defect in foil-prepacked fully-ripened red-smear cheese portions, the microbial composition of 47 smear samples from 2 cheese varieties was analyzed. Cheese variety M was characterized by a diversity of 27 different bacterial species of which 11 represented typical smear microorganisms belonging to Arthrobacter, Brachybacterium, Brevibacterium, Corynebacterium, Microbacterium and Staphylococcus. For variety T 29 different species were identified with 12 isolates representing typical smear microorganisms. Further isolates represented members of Bacillus, Citrobacter, Enterococcus, Facklamia, Morganella, Proteus and Vagococcus. Culture-dependent analysis revealed a stable microbial composition that was confirmed by culture-independent techniques. However, several bacteria with potential to contribute to smear defects by off-flavor or exopolysaccharide production were identified. Our results indicate that the cause of the defect might not be assigned to a single microbial group but rather to the contribution of various microorganisms and their metabolic activity within the foil.