Microbial succession and identification of Micrococcaceae in dried beef cecina, an intermediate moisture meat product

Abstract

Changes in the microflora of Spanish cecina (a salted dried and smoked beef meat product) during ripening were investigated. Twenty-one cecinas divided into seven groups of three pieces each were studied. Cecinas were sampled internally and externally, and the following microbial groups were studied: salt tolerant flora, Micrococcaceae , lactic acid bacteria and yeasts. The results obtained indicated that Micrococcaceae constituted the predominant flora both on the surface and in the interior of the pieces throughout the curing period. The values obtained were higher on the surface (10 7 cfu g −1 ) than in the deep tissue (10 3 –10 4 cfu g −1 ). Yeast and lactic acid bacteria were also found in considerable numbers in both locations. Identification of the 159 isolates belonging to the family Micrococcaceae revealed that 81% belonged to the genus Staphylococcus and include the species S. equorum (43%), S. xylosus (29%), S. saprophyticus (11%) and S. simulans (8%) as the most abundant species. The remainder belonged to the genus Micrococcus (11%) or were unknown (8%). The proportions of Staphylococcus spp. and Micrococcus spp. varied with salt content and water activity. Variations in pH did not appear to influence the microbiology of this product.