Study on the Influence of Pasture on Volatile Fraction of Ewes’ Dairy Products by Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry

Solid-phase microextraction/GC-MS profiles of milk samples M1, M2, and M3 (peaks are numbered as in Table 3).

Solid-phase microextraction/GC-MS profiles of ricotta cheese samples R1, R2, and R3 (peaks are numbered as in Table 3).

Solid-phase microextraction/GC-MS profiles of Caciotta cheese samples at 2 mo of ripening: A) total chromatogram of C2 sample; B) enlarged view of chromatograms of C1 and C3 samples. Peaks are numbered as in Table 4; C1, C2, and C3 represent cheeses made from milk from ewes pastured on each of 3 pastures.

Electron impact and chemical ionization (CI) spectra of the unknown compound eluting at 31.5min.

Molecular structures of β-farnesene and (E,E)-3,7,11-trimethyl-2,4,10-dodecatriene.

Principal components analysis biplot on the first and second eigenvector (57.6% of the total variance explained) of 27 samples (objects) and 15vol.tile compounds (variables) in C1 (○); C2 (▵), C3 (□); C1, C2, and C3 represent cheeses made from milk from ewes pastured on each of 3 pastures. Numbers inside the symbols indicate the ripening time: immediately after production (0), 1 mo (1), and 2 mo (2).

Principal components analysis biplot on the second and third eigenvector (43% of the total variance explained) of 27 samples (objects) and 15vol.tile compounds (variables) in C1 (○); C2 (▵); C3 (□); C1, C2, and C3 represent cheeses made from milk from ewes pastured on each of 3 pastures. Numbers inside the symbols indicate the ripening time: immediately after production (0), 1 mo (1), and 2 mo (2).