On the microbiology of Serra da Estrela cheese: geographical and chronological considerations

Abstract

Serra da Estrela cheeses, produced following artisanal practices from raw ewe's milk in two consecutive years in ¢ve selected dairies, were sampled throughout a 60-day ripening period.The viable numbers of themajormicrobial groups (Enterobacteriaceae, staphylococci and yeasts, aswell as such lactic acid bacteria as lactobacilli, lactococci and enterococci)were determined and statistical signi¢cance of the results was assessed. Signi¢cant di¡erences in the viable counts of lactococci, lactobacilli, enterococci, Enterobacteriaceae and staphylococci were found for the various geographical locations, whereas the year ofmanufacture played a signi¢cant role only upon the viable numbers of yeasts and staphylococci.These data backup the claimthat thosemicrobial families usually implicatedwith health hazards are prone to a wide variability, which re£ects the intrinsic heterogeneity associated with production and handling of raw milk in traditional cheesemaking.