MICROBIOLOGICAL QUALITY PARAMETERS OF PAC KAGING MATERIALS USED IN THE DAIRY-INDUSTRY

The microbiological quality of various materials as used for packaging milk and dairy products was examined qualitatively and quantitatively . Arithmetical mean values of total aerobic mesophilic microorganisms associated with the surface of the packaging material were 33 CFU/cm2 (re-usable brown glass milk bottles), 0.13 CFU/cm2 (polyethylene caps) , 1.0 CFU/100 cm2 (paper composite cartons and roll material), 5.6 CFU /100 ml of beaker content (polystyrene yogurt cups), 1.1 CFU/100 cm2 ( polyethylene foil for Mozzarella cheese packaging). Paper board covers as used for the transportation of cheese varieties were investigated as homogenates and turned out to contain relatively higher numbers of bacteria as well as moulds than the remainder. The microbial populatio n of this category of materials was represented mainly by aerobic spor e-formers (arithmetical mean value: 2.8 x 10(5) CFU/g). With the excep tion of some Bacillus cereus positive results detected with glass bott les and board, no pathogenic microorganisms (E. coli, Salmonella sp., Listeria sp., Staphylococcus aureus, potentially mycotoxigenic moulds) were found with the samples. In this study, differences regarding the microbiological load (bacterial as well as yeast and mould counts) be tween new and used glass bottles after routine cleaning in a dairy pla nt, between paper composite cartons and roll material, and among carto ns from different package suppliers are also presented.