Pit cheese : Compositional, microbiological and sensory characteristics

Fossa or pit cheese, a typical product of a small geographical area of central Italy, is produced in limited quantities and is of great economic importance in its market niche. The cheese is made from a mixture of pasteurized cow and sheep milk. After ripening for approximately 60 days, it is aged for about 3 months in pits dug into tuffaceous rock, to give the product a particular, highly valued flavour. To establish which objective parameters may contribute to giving the unique qualities to the product, and to check for correlations between the ageing methods and the characteristics of the cheese, microbiological, chemical and sensorial analyses were carried out on milk, cheese at different ripening stages, cheese aged for 3 months in the pit and cheese aged for the same period in the cheese factory. The pit aged cheese showed notable differences in comparison to the cheese aged in the factory. The Fossa cheese was less hard, but moister, saltier, sharper and sourer, with a more pronounced aroma, than the factory-aged cheese. Chemical analysis showed significantly different values of water content, non-casein and non-protein nitrogen, amount of free amino acids and composition of free amino acids and free fatty acid fractions for the pit aged cheese. Microbiological analysis showed no significant differences between the amount and distribution of lactic and non-lactic microflora in cheeses aged with different modalities. The environmental conditions of the pit, probably together with the presence of molds on the surface of the pitaged cheese, could be responsible for the development of the unique chemical and sensorial characteristics of Fossa cheese.