Bacterial ecology of PDO Coppa and Pancetta Piacentina at the end of ripening and after MAP storage of sliced product

Abstract

The objective of this study was to evaluate the microbiota of two typical Italian PDO delicatessens Coppa and Pancetta Piacentina, produced in Piacenza area (Italy). Classical and molecular approaches were employed, in order to acquire knowledge on their bacterial ecology and its evolution after slicing and MAP storing; thus, the biodiversity of characteristic bacterial community, already present or introduced during such procedures, was studied in both full ripened and sliced samples from two producers (A and B) of the PDO district, packaged under MAP and stored at 2 and 8 °C for 30 days. The microbiota of the two kinds of Italian delicatessen demonstrated peculiar differences, particularly regarding the staphylococci and lactic acid bacteria (LAB) ratio. Moreover, some species within these two groups appeared to be linked to the kind of product: Leuconostoc, Lactobacillus versmoldensis and Staphylococcus saprophyticus were found only in Pancetta while Lactobacillus pentosus, Staphylococcus equorum, Staphylococcus xylosus, Staphylococcus sciuri and Macrococcus caseolyticus occurred only in Coppa. Also, both delicatessens from producer A were richer in LAB compared to those of producer B and the opposite applied for staphylococci. Interestingly, Tetragenococcus halophilus was detectable in all the samples and its presence in the sausage environment has been reported only for Capocollo. Storage did not substantially modify the microbiota composition, the only changes being the relative abundance of same sequences; S. xylosus was prevalent before slicing process and S. equorum at the end of MAP storage at both 2 °C and 8 °C. Concerning microbial contamination during the slicing process, our results suggest that the adopted procedures assure high hygienic quality standard of these typical products, with exception of a contamination by Psychrobacter psychrophilus in Coppa B. The possible origin of species rarely or never reported in the sausage environment and detected in this study is discussed.

Keywords: Bacterial ecology; Cloning; MAP; PCR; PDO delicatessen; Sequencing.