The Microbiology of Traditional Hard and Semihard Cooked Mountain Cheeses.

Traditional cheeses originate from complex systems that confer on them specific sensory characteristics. These characteristics are linked to various factors of biodiversity such as animal feed, the use of raw milk and its indigenous microflora, the cheese technology, and the ripening conditions, all in conjunction with the knowledge of the cheesemaker and affineur. In Europe, particularly in France, the preservation of traditional cheesemaking processes, some of which have protected designation of origin, is vital for the farming and food industry in certain regions. Among these cheeses, some are made in the Alps or Jura Mountains, including Comte, Beaufort, Abondance, and Emmental, which are made from raw milk. The principle of hard or semihard cooked cheese, produced in the Alps and Jura Mountains, was to make a product during the summer—a period during which the animals feed more and milk production is high—with a shelf life of several months that could be consumed in winter. Today, these traditional cheeses are produced according to a specific approach combining science and tradition in order to better understand and preserve the elements that contribute to the distinctiveness of these cheeses. To address this complex problem, a global approach to the role of the raw milk microflora in the final quality of cheeses was initially chosen. The modifications resulting from the elimination of the raw milk microflora, either by pasteurization or by microfiltration, to the biochemistry of the ripening process and ultimately the sensory quality of the cheeses were evaluated. This approach was achieved mainly with experimental hard cooked cheeses. Other types of traditional cheese made with raw and pasteurized milk are also considered when necessary. Besides the native raw milk microflora, traditional lactic starters (natural or wild starters) also participate in the development of the characteristics of traditional hard and semihard cooked mountain cheeses. After an initial description, their roles are described, mainly for Comte.