Do current regulations for raw milk cheeses ensure consumer safety?

Abstract Text: Raw milk cheeses are made from milk that is not pasteurized nor homogenized, and it is currently legal in the US to sell raw milk cheeses that have been aged for at least 60 days. In some studies, raw milk cheeses have been documented to have a more intense flavor than pasteurized cheeses and variations in diets with various pasture species can also affect flavor. In a preference study, 890 consumers sampled Cheddar and Gouda cheeses made either from raw milk or from pasteurized milk. A majority of the consumers preferred the raw milk cheese even though many of them either were not sure or had considered raw milk cheeses to be less safe. However, there can be situations in which pathogenic organisms or resulting toxins could survive the aging process. One study investigated 8 pathogens that were intentionally injected into raw milk that was then used to make Swiss hard or semi hard cheeses. The study showed hard cheeses to be free of inoculated pathogens one week after production. The semi hard cheeses were free of most pathogens and toxic metabolites except for Listeria monocytogenes, which had survived the manufacturing and ripening process. A recent study that used milk spiked with various strains of E. coli resulted in detection of E. coli in almost all cheeses at the end of the 16-wk ripening period, which could be a food safety issue. In contrast to studies in which pathogens were injected into milk, most raw milk produced for small scale artisan cheese making in Vermont was of high microbiological quality with no detectable target pathogens in the cheese. Aging for 60 d seems effective for eliminating or reducing most pathogens but frequent testing to ensure milk is pathogen free before making cheese is recommended.

Keywords:  raw milk cheese, pathogens, food safety