Characterization by solid-phase microextraction-gas chromatography of the volatile profile of protected designation...

Montasio is a typical protected designation of origin (PDO) Italian semi-hard and semi-cooked cheese produced in northeast Italy from raw or thermized cow's milk. The PDO label implies that the product has distinctive characteristics that are connected to traditional production methods. The aim of this work was to precisely characterize the volatile fraction of this Italian cheese. The volatile profile can be considered a fingerprint because the flavor of a cheese variety is the result of a specific balance between the volatile compounds produced during the ripening process. Analysis of the volatile profile of Montasio cheese was performed by solid-phase microextraction-gas chromatography. Six cheesemaking trials were performed, each in a different dairy located within the Montasio cheese production area. Cheeses were analyzed at 5 stages of ripening (60, 90, 170, 300, and 365 d). Only 11 compounds were identified and measured: 5 fatty acids, 3 alcohols, 2 ketones, and 1 ester. The limited number of volatile compounds measured in the headspace of the Montasio cheese is probably due to the specific making process of this cheese, which affects evolution of the microflora and the biochemical processes of ripening. The total volatile fraction profile progressively increased from 60 to 170 d, after which time it remained almost steady. The most important contributors were found to be ethanol, short-chain fatty acids (C(2) to C(6)), diacetyl, and ethyl hexanoate. Ethanol and short-chain fatty acids increased up to 170 d, diacetyl increased up to 300 d and then declined, and ethyl hexanoate increased until the final stage.