Absolutes of Enfleurage

(d) Absolutes of Enfleurage.


As mentioned previously, an extrait contains not only the natural flower oil, but also a small quantity (about 1 per cent) of alcohol soluble fat, dissolved from the corps, which cannot be eliminated, even by cooling the extrait far below 0o. When concentrating the extrait by distilling off the alcohol, the content of natural flower oil and fat increases correspondingly. Complete concentration in a vacuum still at low temperature results in a concentrated flower oil, free from alcohol, the so-called absolute of enfleurage.
The crude absolutes of enfleurage are usually of dark color and, because of their fat content, of a semisolid consistency. Lighter colored products of more liquid consistency can be obtained by certain methods of purification whereby more fat is eliminated. Further elimination of fat and purification increases the price of the final absolute. Every manufacturer has his own standards in this respect.
These so-called absolutes of enfleurage, absolutes of pomade, concentrates of pomade or liquid concretes were widely employed before the introduction of the more modern process of extraction with volatile solvents. Even today these absolutes of enfleurage find favor with some perfumers because of their lower price. Experts, however, claim that the absolutes of enfleurage when redissolved in alcohol are somewhat inferior to the original alcoholic extraits. Apparently during the process of concentration certain constituents of the natural flower oil, especially the most volatile and delicate ones, are lost.
A characteristic of absolutes of enfleurage is that they have a slight but noticeable "by-note" of vanillin quite alien to the true flower perfume. This note originates from the minute quantities of benzoin incorporated into the fat corps for protection against rancidity. Soluble in alcohol, the benzoin dissolves when the pomades are extracted with alcohol and upon concentration it accumulates in the absolute.

comment 0 nhận xét:

Post a Comment

 
© Pharmacognosy | Plants | herbal | herb | traditional medicine | alternative | Botany | © Copyright 2012 ; Email: epharmacognosy@gmail.com