Perfumes 1 Perfumes Wolfgang Sturm, Haarman & Reimer GmbH, Holzminden, Federal Republic of Germany Klaus Peters, Haarman & Reimer GmbH, Holzminden, Federal Republic of Germany 1. Introduction... 1 2. Raw Materials and Production... 1 3. Perfume Compositions... 4 4. Development of Extrait Perfumes... 4 4.1. Fragrance Concepts... 4 4.2. Fragrance Notes... 5 5. Perfumes for Cosmetics, Toiletries, and Household Products... 5 6. Economic Aspects... 6 7. References... 6 1. Introduction Although perfumes are alcoholic aqueous solutions of perfume oils, the term perfume is often used to denote concentrated perfume oil. Perfume oils may be composed of complex natural products, as well as natural or synthetic fragrance substances. The art of perfumery consists of combining a wide range of raw materials to create a harmonious, pleasant, and expressive fragrance. History. Mixtures of fragrance substances (odorants) in the form of incense (Latin perfumum) and perfumed unguents were used for ceremonial purposes in early times. Along with their ritual uses, perfumes became important among the Greeks and Romans as luxury items. After the isolation of essential oils from green plants, bark, wood, and herbs the art of perfumery advanced rapidly and became fully established during the Renaissance. French perfumery has held a dominant position in Europe since the reign of Louis XII (ca. 1500). Around 1700, Giovanni Paolo Feminis,an Italian who had migrated to Cologne, began marketing what later became eau de cologne. The classic formula for this product consists of bergamot oil, lemon oil, orange oil, and orange flower oil in ethanol. The original name aqua mirabilis ( marvellous water) was replaced by aqua coloniensis and Kölnisch Wasser (Colonia is the Latin name of the city of Cologne, and Köln is its German name), and finally, by eau de cologne. Several firms in the city, including Johann Maria Farina and 4711, made eau de cologne a world-famous product. Modern perfumery began at the end of the 19th century when the first synthetic fragrance substances became available. The initially modest selection of natural products was subsequently extended in a few decades as a result of intensive research and advances in production technology. The importance of perfumery has increased greatly since then. It includes not only the manufacture of fine products (perfume and eau de cologne), but also the use of perfumes in cosmetics, toiletries, soaps, and household or industrial products. In addition to French perfumery, North American perfumery has become very important in recent years. With respect to distinctive fragrance types as well as market volume, these two sources now enjoy a virtually equal status. 2. Raw Materials and Production The raw materials used in perfumery are essential oils, floral oils, extracts from plants and from animal secretions, fragrance substances isolated from natural products, and purely synthetic aroma chemicals. The number of natural fragrance substances is limited, but the increasing refinement of analytical techniques continues to yield new and interesting natural products. Chemical synthesis is, however, mainly responsible for the steady stream of innovations in perfumery since the turn of the 20th century. The production and properties of aroma chemicals and fragrance substances are described elsewhere ( Flavors and Fragrances). c 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002/14356007.a19 171
2 Perfumes Raw Materials of Plant Origin. The following products are isolated from plant raw materials: 1) Essential oils, obtained by pressing plant materials or by steam distillation 2) Concretes, obtained by extraction with volatile solvents such as petroleum ether, benzene derivatives, or alcohols 3) Resinoids, produced by extraction of aromatic resins, mosses, balsams, and roots with volatile solvents 4) Absolutes, derived by treating concretes and resinoids with ethanol The starting materials for these products are 1) flowers such as lavender, rose, jasmine, and neroli (orange flower); 2) stalks and leaves such as geranium, patchouli, and petitgrain; 3) fruit such as anise, coriander, caraway, cumin, and juniper; 4) peel of citrus fruits such as bergamot, lemon, and orange; 5) seeds such as mace, angelica, celery, and cardamom; 6) roots such as angelica, costus, and iris; 7) wood such as sandalwood, guaiac, cedar, and bois de rose; 8) herbs and grasses such as tarragon (estragon), lemongrass, sage, and thyme; 9) needles and twigs of spruce, fir, and pine; and 10) resins and balsams such as those derived from galbanum, elemi, benzoin, myrrh, olibanum, and opopanax. Both the natural products and the aroma chemicals isolated from them are employed in perfumery. Examples of the latter are geraniol and citronellal from citronella oil, citral from lemongrass or Litsea cubeba oil, eugenol from clove oil, and menthol from peppermint oil. Raw Materials of Animal Origin. Raw materials of animal origin are becoming increasingly rare and expensive. The following are used: 1) Ambergris, a metabolic product excreted by sperm whales that may result from a pathological condition 2) Musk, a glandular secretion of a hornless deer of Central Asia 3) Civet, a glandular secretion of the civet cat 4) Castoreum, a glandular secretion of the beaver Semisynthetic and Synthetic Aroma Chemicals. Semisynthetic products are obtained by chemical modification of a natural starting material. They include hydroxycitronellal from citronellal, citronellol from geraniol or citronellal, geranyl acetate from geraniol, and ionones and methylionones from citral. Purely synthetic fragrance substances are produced from basic chemicals by complete synthesis. They can be divided into products that are identical to natural ones and products that do not occur in nature. Products identical to natural substances but obtained by chemical synthesis include benzyl acetate from toluene, phenethyl alcohol from benzene, menthol from thymol, and linalool, a product of acetylene synthesis. Other synthetic aroma chemicals have molecular structures completely different from those of natural products. They can be produced only by chemical synthesis, and often imitate the olfactory impressions of natural raw materials. Examples are 4-tertbutylcyclohexyl acetate (woody note, violet note), α-amylcinnamaldehyde ( jasmine), 4- tert-butyl-α-methylhydrocinnamaldehyde (cyclamen), musk ketone (musk), and ethylene brassylate (musk). Many natural products will continue to be indispensable in perfumery. However, synthetic products are playing an increasingly important role in the perfumer s assortment of raw materials because of their virtually unrestricted availability, constant quality, and generally steady price. Modern analytical techniques allow identification of the components of natural mixtures, which are often very complex. Reconstitution of these products and of essential oils by synthetic materials has led to substitutes with olfactory distinction. Fixatives. Fixatives are used to equalize the vapor pressures, and thus the volatilities, of the raw materials in a perfume oil, as well as to increase the tenacity. Natural fixatives are resinoids (benzoin, labdanum, myrrh, olibanum, storax, and tolu
Perfumes 3 Table 1. Floral bouquet Composition Quantity, g Compound Top note 5 2-undecylene aldehyde 5 ω-decenol 20 2,6-dimethyl-2-heptanol 60 dihydromyrcenol 50 bergamot oil 30 linalool 10 neroli oil Floral complex rose 50 citronellol rose 30 geraniol rose 80 phenethyl alcohol lilac 25 terpineol jasmine 75 α-hexylcinnamaldehyde jasmine 25 α-amylcinnamaldehyde jasmine 30 benzyl acetate lily of the valley 120 4-tert-butyl-α-methylhydrocinnamaldehyde lily of the valley 40 4-(4 -hydroxy-4 -methylpentyl)-3-cyclohexene carboxaldehyde lily of the valley 10 4-isopropyl-α-methylhydrocinnamaldehyde gardenia 15 styrolyl acetate iris violet 60 γ-methylionone iris violet 25 4-tert-butylcyclohexyl acetate clove 10 eugenol clove 5 eugenol methyl ether Fixation sweet 25 cinnamic alcohol sweet 20 coumarin wood 60 acetylcedrene acetylthujopsene ambergris 5 1,2-furano-2,5,5,8a-tetramethyldecalin (10 %) in diethyl phthalate musk 70 6-acetyl-1,1,2,4,4,7-hexamethyltetralin musk 10 cyclopentadecanolide musk 30 musk ketone (4-tert-butyl-2,6-dimethyl-3,5-dinitroacetophenone) 1000 balsam) and animal products (ambergris, castoreum, musk, and civet). Synthetic fixatives include substances of low volatility (cyclopentadecanolide, ambroxide, benzyl salicylate) and virtually odorless solvents with very low vapor pressures (benzyl benzoate, diethyl phthalate, triethyl citrate). Solvents. The only solvent used in fine perfumery is extremely pure ethanol that is diluted with water to the required concentration. Weakly odorous synthetic fixatives are used as solvents for alcohol-free perfumes, especially bazaar oils. ( Bazaar oils are perfume oils that are dissolved in an oily solvent; they are sold in bazaars in Arabian countries and used as perfumes.) Production. Perfumes were originally prepared from alcoholic infusions, solutions, and tinctures of floral extracts, essential oils, natural and artificial aroma chemicals, drugs, and resins. The long storage times allowed complete clarification and maturing of the alcoholic solutions, so that the perfumes required a much shorter aging time. As a result of increasing industrialization, perfumery has departed from these classical methods of preparation. Today, perfume compositions prepared in the form of perfume oils are dissolved in ethanol, cooled to ca. 0 C, filtered, packaged, stored, and marketed. Perfume (extrait) may be for example, a 10 20 vol% solution of a perfume oil in ca. 90 95 vol% ethanol. An eau de toilette or eau de parfum contains ca. 7 10 vol % perfume oil in 80 90 vol % ethanol; an eau de cologne (Kölnisch Wasser), up to 4 vol % perfume oil in ca. 70 85 vol % ethanol. 3. Perfume Compositions In building up a composition, the perfumer must work systematically and observe certain rules of workmanship. A fragrance can be divided into three parts:
4 Perfumes 1) Top note or initial fragrance impression 2) Body note or middle note 3) End note or dry out The odor must pass smoothly from one phase of this cycle to the next; the overall character of the perfume should be clearly perceptible from the top note to the end note, and must impart its own unmistakable note to the fragrance. Linear Compounding. A sample formula is described to illustrate the formulation of a floral fragrance. This formula also demonstrates the technique of linear composition, which is based primarily on well-defined aroma chemicals, essential oils, and floral oils. Complex compounding, on the other hand, mainly uses predesigned and balanced perfume bases and fragrance complexes. Sample Formula. The fragrance materials in the floral bouquet (Table 1) correspond to a variety of flowers; they give a basic, inherently rounded floral complex. Nuancing agents for the top note are fresh-flower components such as ω- decenol and 2,6-dimethyl-2-heptanol, whereas several sweet, woody, and musk odorants such as acetylcedrene acetylthujopsene and 6-acetyl- 1,1,2,4,4,7-hexamethyltetralin serve as fixatives. Table 2. Rose base Composition Quantity, g Compound Top note 15 2-undecylene aldehyde (10 %) in diethyl phthalate 5 ω-decenol 5 phenylacetaldehyde dimethyl acetal 20 decanal (1 %) in diethyl phthalate Body 300 phenethyl alcohol 200 citronellol 100 geraniol 20 geranyl acetate 160 phenethyl diethylacetate 25 nerol 20 farnesol 25 nerolidol 5 eugenol Fixation 20 trichloromethylphenyl carbinyl acetate 30 cinnamic alcohol 50 phenethyl phenylacetate 1000 Complex Compounding. In complex compounding, separately balanced perfume bases are used instead of individual fragrance materials or fragrance accords. These bases consist of numerous components; appropriate mixtures of synthetic products are also substituted for the fragrance complexes of natural essential oils. The complex method yields a more wellrounded composition than a number of individual fragrance materials. For example, the simple rose accord in the floral bouquet (Table 1), consisting of citronellol, geraniol, and phenethyl alcohol, can be replaced by a rose base (Table 2) whose composition has been worked out in much more detail. Replacement of fragrance notes composed of a few substances, as described in Table 1, by sophisticated perfume bases of appropriate odor type yields a composition consisting of several hundred components that has an exceedingly complex makeup and a very rounded odor. 4. Development of Extrait Perfumes 4.1. Fragrance Concepts Extrait perfumes set the trends for all developments in perfumery. They are important for any creative perfumer, regardless of the application for which new fragrance compositions are being developed. The many perfumes now on the market can be classified according to three main fragrance concepts: 1) Floral concept Benzyl acetate (jasmine) α-amylcinnamaldehyde (jasmine) α-hexylcinnamaldehyde (jasmine) Indole (jasmine) Jasmine absolute (jasmine) Terpineol (lilac) Anisaldehyde (lilac) Phenethyl alcohol (rose) Geraniol (rose) Citronellol (rose) Rose oil (rose)
Perfumes 5 Hydroxycitronellal (lily of the valley) 4-tert-Butyl-α-methylhydrocinnamaldehyde (lily of the valley) 4-(4-Hydroxy-4-methyl-pentyl)-3- cyclohexene carboxaldehyde (lily of the valley) Ionones (iris violet) Methylionones (iris violet) Eugenol (clove) Isoeugenol (clove) Clove oil (clove) Joy (Patou, 1935); L Air du Temps (Ricci, 1948); Fidji (Laroche, 1966); Diorella (Dior, 1972); Charlie (Revlon, 1973); Chloé (Lagerfeld, 1975); Giorgio (Beverly Hills, 1981); Poison (Dior, 1985). 2) Oriental Note Concept Vanillin, coumarin, tonka bean extract, and musk aroma chemicals Shalimar (Guerlain, 1925); Youth Dew (Lauder, 1952); Opium (St. Laurent, 1977); Must de Cartier (Cartier, 1981). 3) Chypre Concept Combination of bergamot oil, oakmoss extracts, and patchouli oil Chypre (Coty, 1917); Cabochard (Grès, 1958); Miss Dior (Dior, 1947); Intimate (Revlon, 1955); Coriandre (Couturier, 1973); Ysatis (Givenchy, 1984). 4.2. Fragrance Notes Within each fragrance concept, individual fragrance notes can dominate. Examples follow. 1) Green Note Hexanol, hexenol, and their esters; galbanum oil Floral concept: Vent vert (Balmain, 1945) Chypre concept: Alliage (Lauder, 1972) 2) Aldehydic Note Aliphatic aldehydes (C 6 C 14 ) Floral concept: Chanel No. 5 (Chanel, 1921) Chypre concept: Ma Griffe (Carven, 1944) 5. Perfumes for Cosmetics, Toiletries, and Household Products Perfumes and eaux de cologne are used specifically for their odor. In cosmetics, toiletries, and household products, the perfume is usually of secondary importance for the effectiveness of the product; it may, however, strongly influence the consumer s decision to buy a product and, in many cases, represents the only way of making the product s action perceptible to the consumer. Although the model fragrance types are often created in the field of fine perfumery, chemical and physical aspects must also be taken into account in the development of perfume oils for toiletries and household products. For example, the perfume oil used in creams and white soaps must not cause discoloration; a perfume oil for aftershave lotion must be soluble in 50 60 % alcohol; the fragrance used in a powdered detergent must be alkali resistant; a fabric softener is expected to leave clothes with a pleasant odor; and even a household cleanser must have a pleasant and functional odor, although active chlorine places extraordinary demands on the stability of the perfume oil. Minimal perfume doses are expected to adequately mask the often strong and unpleasant odors of products such as insecticides, floor cleanser, paints, and varnishes. Fragrances for soaps must satisfy the following requirements: chemical resistance, low volatility of raw materials (e.g., geraniol and ionone), strength of odor in soap (e.g., citronellal and γ-decalactone), and adhesion to the skin (e.g., 1,2-furano-2,5,5,8a-tetramethyldecalin and α-amylcinnamaldehyde). In
6 Perfumes the past, well-defined perfume types such as lavender, citronella, rose, lilac, pine, and fern (fougère) were preferred. Today, however, perfumes are custom formulated, usually in fantasy notes with a fresh, invigorating impact or oriented to fine personal- care cosmetics. Olfactory enhancement of all types of household products has become increasingly important in recent decades. The development of perfume oils for this wide-ranging field requires a special knowledge of perfumery, as well as information about the chemical and thermal stability of the perfumery materials used and their impact and substantivity in relation to the product being perfumed. [Substantivity denotes the affinity of a perfume material for a substrate, e.g., fibers (fabric conditioners) or hair (hair conditioners).] 6. Economic Aspects Although no sales figures have been disclosed, worldwide consumption of perfume oils for all applications in 1984 was estimated at ca. 1.8 10 9 (ca. 2.3 10 9 $). Detergents and household products account for ca. 30 % of this total, soaps for 20 %, cosmetics and toiletries for 30 %, and perfumes or eaux de cologne for 20 %. 7. References 1. S. van Toller, G. H. Dodd: Perfumery, the Psychology and Biology of Fragrances, Chapman and Hall, London 1989. 2. G. Ohloff: Riechstoffe und Geruchssinn, Springer Verlag, Heidelberg 1990. 3. Haarman & Reimer: The H + R Book of Perfume, Johnson Publications, London 1984. 4. C. Jellinek: Praktikum des modernen Parfumeurs, Urban & Schwarzenberg, Wien 1949. 5. C. Jellinek: Die psychologischen Grundlagen der Parfümerie, Hüthig Verlag, Heidelberg 1951. 6. J. S. Jellinek: Parfümerien von Produkten, Hüthig Verlag, Heidelberg 1976. 7. Genealogie der Extrait-Parfums, Haarmann & Reimer, Holzminden 1979. 8. W. E. Dorland, J. A. Rogers, Jr.: The Fragrance and Flavor Industry, Wayne E. Dorland Comp., Mendham, New Jersey 1977. Perline Silicates Peroxides Peroxo Compounds, Inorganic