Cheeses
56 Italian DOP cheeses are actually registered; however, we have excluded cheeses for which LAB do not contribute to the formation of aroma during ripening because they are too fresh, or because their aroma is also defined by other microorganisms such as yeasts, moulds or surface bacteria.
Four different cheese varieties were rationally chosen, based on the strong contribution given by autochthonous lactic acid bacteria (LAB) to the distinctive aromatic characteristics of the cheeses.
Grana Padano (GP) PDO and Parmigiano Reggiano (PR) PDO
Grana Padano (GP) PDO and Parmigiano Reggiano (PR) PDO cheeses and “grana type” cheeses (obtained in- or outside the PDO production area following exactly or not exactly the technological production specification) are characterized by a long ripening time (at least 9-12 months).
Although the two PDO cheeses are quite distinct, together, they are the most produced and most exported Italian PDO cheeses in the world.
GP and PR are hard cooked long ripened cheeses manufactured in the region of Northern Italy with raw cow’s milk and thermophilic NWS (5).
"Per gentile concessione del Consorzio per la Tutela del Parmigiano Reggiano"
Robiola di Roccaverano (RR) PDO
Robiola di Roccaverano (RR)/Roccaverano (R) PDO is a soft and creamy cheese produced in the Piedmont Region, manufactured without the use of commercial starter (6).
RR/R can be consumed as fresh cheese after 4 days or allowed to ripen for up to 15 days. Among PDO cheeses, RR/R holds high social and economic interest in the Piedmont region, and it is the only Italian goat milk cheese that has been awarded with a PDO (6).
Non-PDO Robiola cheeses are produced in the same area or in other areas manufactured with similar technologies.
"Per gentile concessione del Consorzio per la Tutela del Formaggio Robiola di Roccaverano"
Caciocavallo Silano (CS) PDO
Caciocavallo Silano (CS) PDO is a semi-hard pasta filata cheese manufactured with raw or mildly thermally treated cows’milk and natural whey starter (7- 9).
Its manufacture is limited to the regions of Calabria, Campania, Molise, Puglia and Basilicata where the mountain chains of the ‘Sila’ are located and its production area represents the second largest area in Italy, after PDO GP cheese one.
In such a large area, the production of non-DOP cheeses is widespread and they are marketed under the same name “Caciocavallo”.
"Per gentile concessione del Consorzio per la Tutela del Formaggio Caciocavallo Silano"
Cheeses sensorial properties
The sensorial properties of these cheeses are defined by interaction of complex factors such as milk type, technological parameters and microbial consortia (10). Among the sensorial properties, cheese aromatic fraction is composed of several volatile compounds belonging to different chemical classes present simultaneously in different amounts (11,12).
All these substances may have a different origin: starting from raw or pasteurized milk, or they can be generated by LAB metabolism during the different steps of cheese-making.
The application of two “omics” techniques can gain a deeper understanding of the various contributions of the microbial players of cheese transformation and evaluate if and how it is essential to favour the development of desirable taxa (13).
The crucial volatile profile can be evaluated by means of HS-SPME/GC-MS technique coupled with the application ofmultivariate statistics (14).
To evaluate the metabolic activity of LAB potentially involved in aroma production in cheese, the recent development of shotgun metagenomics offers the possibility to study food microbiome allowing direct sequencing of whole genomes directly from food matrix (15).
The outcome of this technique is a picture of the entire microbial community, with a resolution to strain level, allowing functional profiling of specific microbial communities.
6) Gatti M, et al. (2014). Invited review: Microbial evolution in raw-milk, long-ripened cheeses produced using undefined natural whey starters. J Dairy Sci, 97:573–91.
7) G.U. Repubblica Italiana Serie Speciale, 18 marzo 2023.
8) Biolcati F, et al (2020). Short communication: High-throughput sequencing approach to investigate Italian artisanal cheese production. J Dairy Sci, 103:10015–10021.
9) Ercolini D, et al (2008). Microbial diversity in Natural Whey Cultures used for the production of Caciocavallo Silano PDO cheese. Int J Food Microbiol, 124:164–170.
10) De Angelis M, et al. (2011). Cheese. Pasta-Filata Cheeses: Traditional Pasta-Filata Cheese. In: Fuquay John W. Encyclopedia of Dairy Sciences (Second Edition), Academic Press, pp 745-752.
11) Succi M, et al (2016). Variability in chemical and microbiological profiles of long-ripened Caciocavallo cheeses. J Dairy Sci, 12:9521–9533.
12) Gobbetti M, et al (2018). Drivers that establish and assembly the lactic acid bacteria biota in cheeses. Trends Food Sci Technol, 78:244–254.
13) Moio L, Addeo, F (1998). Grana Padano cheese aroma. J Dairy Res, 65: 317-333.
14) Esposito G, et al (2014). Fatty acid and sensory profiles of Caciocavallo cheese as affected by management system. J Dairy Sci, 97:1918–1928.
15) Afshari R, et al (2020). New insights into cheddar cheese microbiota-metabolome relationships revealed by integrative analysis of multi-omics data. Sci Rep, 10:1-13.
16) Abbatangelo M, et al (2018). Application of a novel S3 nanowire gas sensor device in parallel with GC-MS for the identification of Parmigiano Reggiano from US and European competitors. J. Food Eng, 236: 36–43.
17) Yeluri Jonnala BR, et al. (2018). Sequencing of the cheese microbiome and its relevance to industry. Front Microbiol, 9:1020.
