Automatic Milking Systems in the Production of Parmigiano Reggiano Cheese: Effects on the Milk Quality and on Cheese Characteristics

The adoption of innovative processes, such as the automatic milking system (AMS), in the production of typical PDO cheeses, such as Parmigiano Reggiano, needs to be evaluated and tested, to verify its influence on milk quality and the typicality of the product. The present research was aimed to study the effect of the introduction of the AMS on the cheesemaking characteristics of the milk and the ripening process and the sensory properties of the Parmigiano Reggiano PDO cheese. Six cheesemaking trials were performed and, in each trial, two different separated pools of milk were submitted to the cheesemaking process in parallel, one from AMS and the other from a traditional milking parlor (TMP). AMS milk, in comparison with TMP one, showed higher content of lactose and calcium and lower contents of somatic cells, thermophilic lactic acid bacteria and chloride. Nevertheless, these changes were too small to influence the efficiency of the cheesemaking process and the cheese composition and its sensory profile. Moreover, cheeses made with AMS milk fully complied with the sensory characteristics of Parmigiano Reggiano cheese PDO, as defined by the PDO rules.

Evolution of the biochemical and microbiological characteristics of mountainous Kefalotyri cheese during ripening and storage

As artisanal cheeses are gaining recognition during the last years by consumers, efforts should be made to standardize their manufacture in order to produce safe products of high and constant quality, supporting the local economy and spreading them outside the region of origin. In this work, the biochemical and microbiological characteristics of Kefalotyri cheese produced during summer in the mountains of Pindos using an artisanal cheesemaking procedure were studied. Sheep raw cheese milk was used without starter culture addition for Kefalotyri cheese manufacture. At 90 days of ripening and storage (the date that hard cheese can be sold in the market), its moisture was 40.4%, fat 28.8%, salt 4.1% and proteins 23.3%. Butyric acid and 3methyl butanoic acid were the most abundant volatile compounds found in this cheese. Mesophilic lactic acid bacteria and cocci were dominated; high numbers of thermophilic lactic acid bacteria and cocci, enterococci and Enterobacteriaceae were also present and the microbiological data revealed a rather satisfactory hygienic sanitary condition of the cheeses.

Characterization of Yeasts Isolated From Parmigiano Reggiano Cheese Natural Whey Starter: From Spoilage Agents to Potential Cell Factories for Whey Valorization

Whey is the main by-product of the dairy industry and contains sugars (lactose) and proteins (especially serum proteins and, at lesser extent, residual caseins), which can be valorized by the fermentative action of yeasts. In the present study, we characterized the spoilage yeast fraction inhabiting natural whey starter (NWS), the undefined starter culture of thermophilic lactic acid bacteria used in Parmigiano Reggiano (PR) cheesemaking, and evaluated thermotolerance, mating type, and the aptitude to produce ethanol and bioactive peptides from whey lactose and proteins, respectively, in a selected pool of strains. We found that PR NWS yeast population consists of other species (Saccharomyces cerevisiae, Wickerhamiella pararugosa, and Torulaspora delbrueckii) in addition to the well-documented Kluyveromyces marxianus, with multiple biotypes scored within each species. Haploid and diploid K. marxianus strains were identified through MAT genotyping, while thermotolerance assay allowed the selection of strains suitable to grow up to 48 °C. In whey fermentation assay, one thermotolerant strain was suitable to release ethanol with yield of 86.5%, while another candidate was able to produce the highest amounts of both ethanol and bioactive peptides with potentially anti-hypertensive function. The present work demonstrated that PR NWS is a reservoir of ethanol and bioactive peptides producer yeasts, which can be exploited to valorize whey, in agreement with the principles of circularity and sustainability.