This paper examines the distribution of mono-and sesquiterpene secondary metabolites in 47 plants present in grazing areas from which cheeses are produced. In total, 54 terpenoid volatiles, derived from both highland and lowland plants, were obtained by a gaseous purge-and-trap system without the use of organic solvents and then identified by automated GC/MSD-FID analysis using mass spectral libraries, retention indices, and data acquired by the authors with authentic substances. Single ion monitoring proved valuable in identifying overlapping compounds with similar spectra for the subsequent semiquantitative determination of compositions. These are displayed as radar plots. It is suggested that flavor/aroma differences in cheeses produced from animals grazing in different areas and seasons arise from species (n = 38), phenological stages (n = 8), locations (n 4), and seasonal variation in terpenoids present (the most common were trans-beta-ocimene, limonene, and trans-beta-caryophyllene). This hypothesis is supported by the fact that distinct variations in terpenoids with differing odor descriptors and abundances were found., It is also possible that terpenes with a higher polarity are less efficiently recovered by the purge-and-trap method than compounds of lower polarity. As the radar plots display relative concentrations based on detection limits, the relative efficiency of detection for different classes of compounds needs to be taken into consideration
