The microbial composition and its spatial distribution of Grana Trentino, a hard Parmesan-like cheese,was determined, from vat milk to cheese. After cutting along the vertical axis of the cheese wheels, threelayers were sampled diagonally across the cheese: under the cheese rind, an intermediate section and thecheese core. After two different ripening periods (9 and 18 months), the cheese samples were analysedusing traditional culture dependent and culture independent methods. Milk samples were dominatedby mesophilic and psychrophilic bacterial counts. Thermophilic bacteria (Lactobacillus helveticus) werefound in high amounts in cooked whey and natural whey starter cultures. After 9 months of ripening,lactic acid bacteria (LAB) counts were higher than those after 18 months. Furthermore, the LAB numbersin the cheese core was lower than those under the rind or in the intermediate section. The main LABspecies isolated from milk (Lactococcus lactis, Pediococcus pentosaceus, Streptococcus uberis and Lactococcusgarvieae) were not found in the corresponding cheeses. Some differences were observed in the speciescomposition among the three cheese sections. Microbiota under the rind and in the intermediate sectionwas similar and dominated by Lactobacillus paracasei and Lactobacillus rhamnosus. The core, after 18months of ripening, was characterized by a total absence of LAB. In each sample, all LAB were genotypicallygrouped and the different biotypes were subjected to several technological tests indicating that somenon-starter LAB (NSLAB) displayed technological features that are favorable for the production of GranaTrentino cheese.
|Numero di pagine||10|
|Rivista||Systematic and Applied Microbiology|
|Stato di pubblicazione||Published - 2012|
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics
- Applied Microbiology and Biotechnology