Hygienic quality of milk and cheese from local farm producers in Norway

Detection of coliforms is generally used as an indicator of sanitary conditions in dairy production, and elevated coliform counts in milk and dairy products suggest unsanitary conditions during production or processing. The presence of E.coli may indicate poor raw milk quality, inadequate thermising, post-thermising contamination, poor hygiene conditions during processing, storage or packaging. Some of the cheese varieties produced by small farm based producers, such as Camembert, demand good hygienic practice in order to be a safe product. If unthermised milk is used, strict hygienic practice is crucial. The closeness of the food production premises and cheese makers to rich coliform sources as animal faeces, represents a constant risk and demands an acute awareness of the fact. In this study the presence of E.coli/coliforms in raw bovine milk used for farm-produced cheese in the middle region of Norway, Trøndelag, was determined. Raw milk, thermised milk and whey were analysed in three cheese makings at 5 different farms, over a period of 2 winter months (2009). Three cheesemakers made soft-cheese (Camembert), one of these from unthermised milk. Two cheesemakers made hard, ripened cheese, one of these from unthermised milk. Coliforms were analysed using the traditional NMKL 44-method, E.coli was analysed using the NMKL125-method. The majority of the milk and cheese tested were free of E.coli and coliforms. The remaining samples were positive of either E. coli or coliforms or both, but within the compliance limits of Norwegian legislation. E. coli was detected in a few samples of raw milk for thermised production, but not in thermised milk, whey or cheese. Indications of reinfection were found in whey from unthermised production. The results indicate that the locally produced cheese in Trøndelag, Norway has a high microbial quality. This kind of studies gives important data for risk assessments.