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The effect of yoghurt culture Rx on the survival of Staphylococcus aureus CCM 5984 added to milk in various concentrations was observed during the fermentation and storage of yoghurt. The end of the fermentation process (3.5 h) was only accompanied by a slight reduction. During the storage of yoghurt at 4 degrees C a 1-2 log reduction was observed. No Staph. aureus was detected in yoghurt produced from milk contaminated by 10(3) Staph. aureus cells l-1 after 48 h of cold storage. When a concentration of 10(2) Staph. aureus cells was used for milk contamination, the pathogen was not recovered from yoghurt during the fermentation and storage. The fermentation and storage of yoghurt was accompanied by increases in lactic acid and titrimetric acidity, as well as by a decrease in pH value.

Cicoňová P., Laciaková A., Máté D. (2010): Prevention of ochratoxin A contamination of food and ochratoxin A detoxification by microorganisms -a review. Czech J. Food Sci., 28: 465-474.Ochratoxin A is a mycotoxin produced by several fungal species of the genera Aspergillus and Penicillium. This mycotoxin is nephrotoxic, immunosupressive, teratogeni, and carcinogenic to animals and has been classified as a possible human carcinogen. Human exposure to ochratoxin A is worldwide. Ochratoxin A occurs in a variety of foods. An ideal method for minimisation of the health risk that this mycotoxin poses is the prevention of food contamination. When the contamination occurs, the hazard associated with the mycotoxin presence in the food must be eliminated. Various microorganisms such as bacteria and microscopic fungi have been tested for their abilities to prevent ochratoxin A contamination or detoxify foods. Biological control by microorganisms is studied widely, therefore the objective of this article is to provide an overview of the recent development in the biological control of ochratoxin A contamination.

The cereal samples were taken immediately after harvest from the selected localities of Poland (45 samples) and East Slovakia (60 samples). Fungal contamination of these samples was investigated and subsequently the presence of two important mycotoxins, deoxynivalenol (DON) and ochratoxin A (OTA), was quantitatively examined. Concerning mould contamination, no difference was observed between the samples from Poland and East Slovakia. The highest incidence was observed of Fusarium, Aspergillus, and Penicillium genera. However, most of the investigated samples of wheat, rye, and barley contained less than 10 4 cfu/g. The limit 750 ppb for DON in cereals and their products, recommended by the European Mycotoxin Awareness Network (EMAN), was exceeded only by one wheat sample (4.5%) from Poland, but by seven wheat samples (14.6%) from Slovakia. None cereal sample investigated for OTA exceeded the allowed limit -5 µg/kg.