Boronia Absolute

#### Boronia Absolute. **Boronia**** ****Absolute**** **is a unique perfume and flavor material in more than one respect. First of all, it is one of the very few flower absolutes which is not processed into a concrète in the immediate vicinity of the growing areas of the plant. Furthermore, it is one of the few, if not the only, flower absolute which contains **lonones**. Finally, Boronia absolute is an excellent flavor material in addition to being highly appreciated in perfumery. **Boronia Absolute **is produced by petroleum ether extraction of the flowers of **Boronia**** ****Megastigma**** **which grows wild in abundance all along the coasts and swamplands of western and southwestern Australia. Boronia is a small shrub or bushy plant, 4 to 6 feet high. It is related to the citrus tree. The flowers are collected and immersed in drums with petroleum ether. The filled drums are shipped by truck or train to the extraction station. In 1958, there were over 500 flower-collecting stations in western Australia. There are only a few extraction factories. The most important of these is located in Perth on the southwest coast. The extraction process is completed in the factory. The extract is an unctuous, dark green concrète of boronia in a yield of less than 1**% **of the weight of the flowers. An absolute is produced by alcohol washing of the concrète. The yield is 55 to 65% of the weight of the concrète. Boronia concrète is not a commercial article, but the absolute is usually produced by the manufacturer who performs the extraction of concrète from the flowers. **Boronia Absolute **is one of the few natural perfume materials which contain **lonone **(mainly beta ionone, only a little alpha ionone). Although these ketones are present in fairly large amounts, they are not immediately detectable in the odor of boronia absolute. The odor of the dark green and somewhat viscous absolute is fresh, fruity- green, sweet tea-like, slightly spicy-herbaceous (reminiscent of cinnamon and tobacco leaf). The main body notes display a tremendously rich and tenacious floral undertone of warm, woody-sweet character. The great distance between the producing area and the consumers is partly responsible for the unfortunate and regrettable fact that **Boronia Absolute **appears on the market in widely different qualities, some of which do not exactly encourage the perfumer to use boronia in his creations. The more important consumers of true boronia absolute will prefer to deal directly with the producer or his appointed agents. **Boronia Absolute **is used in high class floral perfumes and bases, e.g. violet, mimosa, cassie, honeysuckle, sweet pea, etc., and it blends well with sage clary, bergamot, costus, sandalwood, helichrysum, amylcinnamic aldehyde, linalool, salicylates, etc. However, the high cost (about the same as for jasmin absolute from concrète) and the limited production (less than one metric ton per year) make boronia absolute an item that many perfumers entirely avoid using, or else reach for only with reluctance and scepticism. **Boronia**** ****Absolute**** **is used in flavor work where it imparts a unique body and natural richness to many fruit essences, e.g. raspberry, strawberry, plum, peach (it blends excellently with undecanolide and nonanolide). A special application is typified by the artificial reproduction of black- currant flavor, a very difficult problem for the flavorist. The suggested use level is 0.40 to 0.60 mg%, and the Minimum Perceptible is about 0.01 to 0.03 mg%. Boronia absolute is not infrequently adulterated, "cut" or "stretched" with e.g. ionones, eugenol, methyleugenol, sesquiterpene fractions from ylang-ylang oil, benzylsalicylate, etc.