Perfume and flavor materials of natural origin. Arctander, Steffen. Violet Leaf Absolute.

Perfume and flavor materials of natural origin. Arctander, Steffen.
Violet Leaf Absolute.
Far more important in perfumery than the flower absolute (which is hardly available any more) are the extraction products of violet leaves. The leaves are derived from Viola Odorata, the so-called Victoria variety which is cultivated extensively in the coastal region south of Grasse, France. The plant is also cultivated in northern Italy for the extraction of leaf absolute and, more recently, China has started production of this interesting perfume material.
Violet Leaf Absolute is produced by petroleum ether extraction of the freshly harvested leaves. The resulting extract is the concrete of violet leaves. By alcohol washing, chilling and filtration of the alcoholic extract and subsequent evapora tion in vacuum, an absolute is obtained. This is a viscous liquid, intensely dark green and possessing a very powerful and peculiar odor, truly a green- leaf odor, but with an indisputable floral and delicate note which makes it immediately remin iscent of violets in a bouquet (flowers, stems, leaves).
Although the annual production must be estim ated at only 100 to 250 kilos, Violet Leaf Absolute is used extensively in perfumery where its tre mendous diffusion and delicate naturalness is obtainable at very low concentrations of the absolute in a perfume or base. In certain floral bases, e.g. hyacinth, muguet, reseda, violet, and in high-class chypres, in aldehydic-woody fra grances and in many fantasy types, it lends an unsurpassed elegance when skilfully used. 
It blends excellently with tuberose, narcissus, tea leaf abso lute, michelia leaf oil, anthocephalus cadamba, boronia, clary sage absolute, estragon, cumin, basil, and with numerous synthetic materials. It was used with cyclamal, cuminal, dimethyl heptenal, hop absolute, beta-gamma hexenal, isononyl acetate and propionate, and with certain other synthetic materials for the once fashionable "cucumber"-green note.
In flavors, violet leaf absolute finds some application, but the absolute suffers from the disadvantage of being very unstable in the presence of water (which is the condition ruling in most flavor concentrates, etc.).