Relation entre la composition botanique de végétations de montagne et leur composition en composés volatils

Relationships between the botanical make up of mountain vegetation and the contents of volatile contents in the plants

In order to find objective data linking the quality of cheese to environmental conditions, we studied the relationships between the botanical composition of various mountain pastures and the contents of volatile compounds in the plants ; the idea was to understand how these compounds could influence the organoleptic properties of cheese. Ten samples of mountain vegetations (at from 850 to 1 800 m altitudes) were studied ; several type of aromatic profiles were thus revealed, differing by the contents and nature of volatile compounds, especially terpenes. These profiles were linked to botanical profiles, distinguished by the relative abundance of grasses and various families of dicotyledons. The vegetations of valleys, where grasses are abundant, had low contents of volatile compounds. Largest contents and concentrations of terpenes and esters were found in places where umbellifers and other dicotyledons of cool environment are abundant. Certain alpine pastures, with rosette plants and small umbellifers, contained large amounts of monoterpenes and sulphur-containing compounds. Other alpine pastures, with more abundant grasses, had lower monoterpene contents, but contained larger amounts of furans. These results show the influence of the botanical composition, itself affected by the natural conditions and by forage practices, on the contents of volatile compounds in plants.