MODULE 1 TECHNOLOGY OF COSMETIC PRODUCTS
Content modules: 2. Technology of toiletries and hare care cosmetic products.
PERFUMES & FRAGRANCES.
The word perfume used today derives from the Latin per fumus, meaning “through smoke“. Perfumery, or the art of making perfumes, began in ancient Mesopotamia and Egypt and was further refined by the Romans and Persians.
Although perfume and perfumery also existed in India, much of its fragrances are incense based. The earliest distillation of Ittar, arabic meaning scent, was mentioned in the Hindu Ayurvedic text Charaka Samhita. The Harshacharita, written in 7th century in Northern India mentions use of fragrant agarwood oil.
The world’s first recorded chemist is considered to be a womaamed Tapputi, a perfume maker who was mentioned in a cuneiform tablet from the 2nd millennium BC in Mesopotamia.[2] She distilled flowers, oil, and calamus with other aromatics then filtered and put them back in the still several times.[3]
In 2005,[4] archaeologists uncovered what are believed to be the world’s oldest perfumes in Pyrgos, Cyprus. The perfumes date back more than 4,000 years. The perfumes were discovered in an ancient perfumery. At least 60 stills, mixing bowls, funnels and perfume bottles were found in the 43,000-square-foot (
The Arabian chemist, Al-Kindi (Alkindus), wrote in the 9th century a book on perfumes which he named Book of the Chemistry of Perfume and Distillations. It contained more than a hundred recipes for fragrant oils, salves, aromatic waters and substitutes or imitations of costly drugs. The book also described 107 methods and recipes for perfume-making and perfume making equipment, such as the alembic (which still bears its Arabic name).[7]
The Persian chemist Ibn Sina (also known as Avicenna) introduced the process of extracting oils from flowers by means of distillation, the procedure most commonly used today. He first experimented with the rose. Until his discovery, liquid perfumes were mixtures of oil and crushed herbs or petals, which made a strong blend. Rose water was more delicate, and immediately became popular. Both of the raw ingredients and distillation technology significantly influenced western perfumery and scientific developments, particularly chemistry.
The art of perfumery was known in western Europe ever since 1221, if we consider the monks’ recipes of Santa Maria delle Vigne or Santa Maria Novella of Florence, Italy. In the east, the Hungarians produced in
Concentration
Perfume types reflect the concentration of aromatic compounds in a solvent, which in fine fragrance is typically ethanol or a mix of water and ethanol. Various sources differ considerably in the definitions of perfume types. The intensity and longevity of a perfume is based on the concentration, intensity and longevity of the aromatic compounds (natural essential oils / perfume oils) used: As the percentage of aromatic compounds increases, so does the intensity and longevity of the scent created. Specific terms are used to describe a fragrance’s approximate concentration by percent/volume of perfume oil, which are typically vague or imprecise. A list of common terms (Perfume-Classification) is as follows:
Perfume extract, or simply perfume (Extrait): 15-40% (IFRA: typical 20%) aromatic compounds
Esprit de Parfum (ESdP): 15-30% aromatic compounds, a seldom used strength concentration in between EdP and perfume
Eau de Parfum (EdP), Parfum de Toilette (PdT): 10-20% (typical ~15%) aromatic compounds, sometimes listed as “eau de perfume” or “millésime”
Eau de toilette (EdT): 5-15% (typical ~10%) aromatic compounds
Eau de Cologne (EdC): Chypre citrus type perfumes with 3-8% (typical ~5%) aromatic compounds. “Original Eau de Cologne” is a registered trademark.
Perfume mist: 3-8% aromatic compounds (typical non-alcohol solvent)
Splash (EdS) and After shave: 1-3% aromatic compounds. “EdS” is a registered trademark.
Solvent types
Perfume oils are often diluted with a solvent, though this is not always the case, and its necessity is disputed. By far the most common solvent for perfume oil dilution is ethanol or a mixture of ethanol and water. Perfume oil can also be diluted by means of neutral-smelling oils such as fractionated coconut oil, or liquid waxes such as jojoba oil.
Imprecise terminology
Although quite often, Eau de Parfum (EdP) will be more concentrated than Eau de Toilette (EdT) and in turn Eau de Cologne (EdC), this not always the case. Different perfumeries or perfume houses assign different amounts of oils to each of their perfumes. Therefore, although the oil concentration of a perfume in EdP dilution will necessarily be higher than the same perfume in EdT from within the same range, the actual amounts can vary between perfume houses. An EdT from one house may be stronger than an EdP from another.
Men’s fragrances are rarely sold as EdP or perfume extracts; equally so, women’s fragrances are rarely sold in EdC concentrations. Although this gender specific naming trend is common for assigning fragrance concentrations, it does not directly have anything to do with whether a fragrance was intended for men or women. Furthermore, some fragrances with the same product name but having a different concentratioame may not only differ in their dilutions, but actually use different perfume oil mixtures altogether. For instance, in order to make the EdT version of a fragrance brighter and fresher than its EdP, the EdT oil may be “tweaked” to contain slightly more top notes or fewer base notes. In some cases, words such as extrême, intense, or concentrée that might indicate aromatic concentration are actually completely different fragrances, related only because of a similar perfume accord. An example of this is Chanel’s Pour Monsieur and Pour Monsieur Concentrée.
Eau de Cologne (EdC) since
Describing a perfume
The precise formulae of commercial perfumes are kept secret. Even if they were widely published, they would be dominated by such complex ingredients and odorants that they would be of little use in providing a guide to the general consumer in description of the experience of a scent. Nonetheless, connoisseurs of perfume can become extremely skillful at identifying components and origins of scents in the same manner as wine experts.[8]
The most practical way to start describing a perfume is according to the elements of the fragrance notes of the scent or the “family” it belongs to, all of which affect the overall impression of a perfume from first application to the last lingering hint of scent.[9][10]
Fragrance notes
Perfume is described in a musical metaphor as having three sets of notes, making the harmonious scent accord. The notes unfold over time, with the immediate impression of the top note leading to the deeper middle notes, and the base notes gradually appearing as the final stage. These notes are created carefully with knowledge of the evaporation process of the perfume.
Top notes: The scents that are perceived immediately on application of a perfume. Top notes consist of small, light molecules that evaporate quickly. They form a person’s initial impression of a perfume and thus are very important in the selling of a perfume. Also called the head notes.
Middle notes: The scent of a perfume that emerges just prior to when the top notes dissipate. The middle note compounds form the “heart” or main body of a perfume and act to mask the often unpleasant initial impression of base notes, which become more pleasant with time. They are also called the heart notes.
Base notes: The scent of a perfume that appears close to the departure of the middle notes. The base and middle notes together are the main theme of a perfume. Base notes bring depth and solidity to a perfume. Compounds of this class of scents are typically rich and “deep” and are usually not perceived until 30 minutes after application.
The scents in the top and middle notes are influenced by the base notes, as well the scents of the base notes will be altered by the type of fragrance materials used as middle notes. Manufacturers of perfumes usually publish perfume notes and typically they present it as fragrance pyramid, with the components listed in imaginative and abstract terms.
Fragrance wheel
The Fragrance wheel is a relatively new classification method that is widely used in retail and in the fragrance industry. The method was created in 1983 by Michael Edwards, a consultant in the perfume industry, who designed his own scheme of fragrance classification. The new scheme was created in order to simplify fragrance classification and naming scheme, as well as to show the relationships between each of the individual classes.[11]
The five standard families consist of Floral, Oriental, Woody, Fougère, and Fresh, with the former four families being more “classic” while the latter consisting of newer bright and clean smelling citrus and oceanic fragrances that have arrived due to improvements in fragrance technology. Each of the families are in turn divided into sub-groups and arranged around a wheel.
Characteristics
Natural and synthetics are used for their different odor characteristics in perfumery
|
Naturals |
Synthetics |
Variance |
Vary by the times and locations where they are harvested as well as how the product was extracted from the raw material. It’s much more difficult to produce consistent products with equivalent odor over years of harvest and production. As such, the perfumer has to “manually” balance-out the natural variations of the ingredients in order to maintain the quality of the perfume. In addition, unscrupulous suppliers may adulterate the actual raw materials by changing its source (adding Indian Jasmine into Grasse Jasmine) or the contents (adding linalool to Rosewood) to increase their profit margin. |
Much more consistent thaatural aromatics. However, differences in organic synthesis may result in minute differences in concentration of impurities. If these impurities have low smell (detection) thresholds, the differences in the scent of the synthetic aromatic will be significant. |
Components |
Thousands of chemical compounds; large potential for allergies. |
Depending on purity, consists primarily of one chemical compound. Sometimes chiral mixtures of isomers, such as in the case of Iso E Super.[14] |
Scent Uniqueness |
Bears a slight resemblance scent to its originating material, depending on the how the extraction method denatures the odoriferous compounds. |
Similar to natural scents if the compounds are the same. Novel scent compounds not found in nature will often be unique in their scent and dissimilar to the scents of any naturals. |
Scent Complexity |
Deep and complex fragrance notes. Softer with subtle scent nuances. |
Pure and pronounced fragrance notes. Structural and defined. |
Price |
Perfume composed of largely natural materials are usually much more expensive. Prices are determined by the labor and difficulty of properly extracting each unit of the natural materials as well as its quality. |
Perfumes using largely synthetic aromatics can be available at widely-affordable prices. Synthetic aromatics are not necessarily cheaper thaaturals, with some synthetics being more costly than most natural ingredients due to various factors such as the complexity of synthesis or extraction procedure. However, due to their low odor threshold, one does not need to use much of these materials to produce a perfume. |
Obtaining natural odorants
Before perfumes can be composed, the odorants used in various perfume compositions must first be obtained. Synthetic odorants are produced through organic synthesis and purified. Odorants from natural sources require the use of various methods to extract the aromatics from the raw materials. The results of the extraction are either essential oils, absolutes, concretes, or butters, depending on the amount of waxes in the extracted product.[15]
All these techniques will, to a certain extent, distort the odor of the aromatic compounds obtained from the raw materials. This is due to the use of heat, harsh solvents, or through exposure to oxygen in the extraction process which will denature the aromatic compounds, which either change their odor character or renders them odorless.
Maceration/Solvent extraction: The most used and economically important technique for extracting aromatics in the modern perfume industry. Raw materials are submerged in a solvent that can dissolve the desired aromatic compounds. Maceration lasts anywhere from hours to months. Fragrant compounds for woody and fibrous plant materials are often obtained in this manner as are all aromatics from animal sources. The technique can also be used to extract odorants that are too volatile for distillation or easily denatured by heat. Commonly used solvents for maceration/solvent extraction include hexane, and dimethyl ether. The product of this process is called a “concrete”.
Supercritical fluid extraction: A relatively new technique for extracting fragrant compounds from a raw material, which often employs Supercritical CO2. Due to the low heat of process and the relatively nonreactive solvent used in the extraction, the fragrant compounds derived often closely resemble the original odor of the raw material.
Ethanol extraction: A type of solvent extraction used to extract fragrant compounds directly from dry raw materials, as well as the impure oily compounds materials resulting from solvent extraction or enfleurage. Ethanol extraction is not used to extract fragrance from fresh plant materials since these contain large quantities of water, which will also be extracted into the ethanol.
Distillation: A common technique for obtaining aromatic compounds from plants, such as orange blossoms and roses. The raw material is heated and the fragrant compounds
An old perfume still on display at Fragonard are re-collected
through condensation of the distilled vapour.
Steam distillation: Steam from boiling water is passed through the raw material, which drives out their volatile fragrant compounds. The condensate from distillation are settled in a Florentine flask. This allows for the easy separation of the fragrant oils from the water. The water collected from the condensate, which retains some of the fragrant compounds and oils from the raw material is called hydrosol and sometimes sold. This is most commonly used for fresh plant materials such as flowers, leaves, and stems.
Dry/destructive distillation: The raw materials are directly heated in a still without a carrier solvent such as water. Fragrant compounds that are released from the raw material by the high heat often undergo anhydrous pyrolysis, which results in the formation of different fragrant compounds, and thus different fragrant notes. This method is used to obtain fragrant compounds from fossil amber and fragrant woods where an intentional “burned” or “toasted” odor is desired.
Fractionation: Through the use of a fractionation column, different fractions distilled from a material can be selectively excluded to modify the scent of the final product. Although the product is more expensive, this is sometimes performed to remove unpleasant or undesirable scents of a material and affords the perfumer more control over their composition process.
Expression: Raw material is squeezed or compressed and the oils are collected. Of all raw materials, only the fragrant oils from the peels of fruits in the citrus family are extracted in this manner since the oil is present in large enough quantities as to make this extraction method economically feasible.
Enfleurage: Absorption of aroma materials into solid fat or wax and then extracting the odorous oil with ethyl alcohol. Extraction by enfleurage was commonly used when distillation was not possible because some fragrant compounds denature through high heat. This technique is not commonly used in the present day industry due to its prohibitive cost and the existence of more efficient and effective extraction methods.[9]
Fragrant extracts
Although fragrant extracts are known to the general public as the generic term “essential oils”, a more specific language is used in the fragrance industry to describe the source, purity, and technique used to obtain a particular fragrant extract.
Of these extracts, only absolutes, essential oils, and tinctures are directly used to formulate perfumes.
Absolute: Fragrant materials that are purified from a pommade or concrete by soaking them in ethanol. By using a slightly hydrophilic compound such as ethanol, most of the fragrant compounds from the waxy source materials can be extracted without dissolving any of the fragrantless waxy molecules. Absolutes are usually found in the form of an oily liquid.
Concrete: Fragrant materials that have been extracted from raw materials through solvent extraction using volatile hydrocarbons. Concretes usually contain a large amount of wax due to the ease in which the solvents dissolve various hydrophobic compounds. As such concretes are usually further purified through distillation or ethanol based solvent extraction. Concretes are typically either waxy or resinous solids or thick oily liquids.
Essential oil: Fragrant materials that have been extracted from a source material directly through distillation or expression and obtained in the form of an oily liquid. Oils extracted through expression are sometimes called expression oils.
Pomade: A fragrant mass of solid fat created from the enfleurage process, in which odorous compounds in raw materials are adsorbed into animal fats. Pommades are found in the form of an oily and sticky solid.
Tincture: Fragrant materials produced by directly soaking and infusing raw materials in ethanol. Tinctures are typically thin liquids.[9]
Products from different extraction methods are known under different names even though their starting materials are the same. For instance, orange blossoms from Citrus aurantium that have undergone solvent extraction produces “orange blossom absolute” but that which have been steam distilled is known as “neroli oil”.
Composing perfumes
Perfume compositions are an important part of many industries ranging from the luxury goods sectors, food services industries, to manufacturers of various household chemicals. The purpose of using perfume or fragrance compositions in these industries is to affect customers through their sense of smell and entice them into purchasing the perfume or perfumed product. As such there is significant interest in producing a perfume formulation that people will find aesthetically pleasing.
The perfumer
The job of composing perfumes that will be sold is left up to an expert on perfume composition or known in the fragrance industry as the perfumer. They are also sometimes referred to affectionately as a “Nez” (French for nose) due to their fine sense of smell and skill in smell composition.
The composition of a perfume typically begins with a brief by the perfumer’s employer or an outside customer. The customers to the perfumer or their employers, are typically fashion houses or large corporations of various industries. The perfumer will then go through the process of blending multiple perfume mixtures and sell the formulation to the customer, often with modifications of the composition of the perfume.
The perfume composition will then be either used to enhance another product as a functional fragrance (shampoos, make-up, detergents, car interiors, etc.), or marketed and sold directly to the public as a fine fragrance.[8]
Technique
Although there is no single “correct” technique for the formulation of a perfume, there are general guidelines as to how a perfume can be constructed from a concept. Although many ingredients do not contribute to the smell of a perfume, many perfumes include colorants and anti-oxidants to improve the marketability and shelf life of the perfume, respectively.
Basic framework
Perfume oils usually contain tens to hundreds of ingredients and these are typically organized in a perfume for the specific role they will play. These ingredients can be roughly grouped into four groups:
Primary scents (Heart): Can consist of one or a few main ingredients for a certain concept, such as “rose”. Alternatively, multiple ingredients can be used together to create an “abstract” primary scent that does not bear a resemblance to a natural ingredient. For instance, jasmine and rose scents are commonly blends for abstract floral fragrances. Cola flavourant is a good example of an abstract primary scent.
Modifiers: These ingredients alter the primary scent to give the perfume a certain desired character: for instance, fruit esters may be included in a floral primary to create a fruity floral; calone and citrus scents can be added to create a “fresher” floral. The cherry scent in cherry cola can be considered a modifier.
Blenders: A large group of ingredients that smooth out the transitions of a perfume between different “layers” or bases. These themselves can be used as a major component of the primary scent. Common blending ingredients include linalool and hydroxycitronellal.
Fixatives: Used to support the primary scent by bolstering it. Many resins, wood scents, and amber bases are used as fixatives.
The top, middle, and base notes of a fragrance may have separate primary scents and supporting ingredients. The perfume’s fragrance oils are then blended with ethyl alcohol and water, aged in tanks for several weeks and filtered through processing equipment to, respectively allow the perfume ingredients in the mixture to stabilize and to remove any sediment and particles before the solution can be filled into the perfume bottles.[16]
Fragrance bases
Instead of building a perfume from “ground up”, many modern perfumes and colognes are made using fragrance bases or simply bases. Each base is essentially modular perfume that is blended from essential oils and aromatic chemicals, and formulated with a simple concept such as “fresh cut grass” or “juicy sour apple”. Many of Guerlain’s Aqua Allegoria line, with their simple fragrance concepts, are good examples of what perfume fragrance bases are like.
The effort used in developing bases by fragrance companies or individual perfumers may equal that of a marketed perfume, since they are useful in that they are reusable. On top of its reusability, the benefit in using bases for construction are quite numerous:
Ingredients with “difficult” or “overpowering” scents that are tailored into a blended base may be more easily incorporated into a work of perfume
A base may be better scent approximations of a certain thing than the extract of the thing itself. For example, a base made to embody the scent for “fresh dewy rose” might be a better approximation for the scent concept of a rose after rain than plain rose oil. Flowers whose scents cannot be extracted, such as gardenia or hyacinth, are composed as bases from data derived from headspace technology.
A perfumer can quickly rough out a concept from a brief by cobbling together multiple bases, then present it for feedback. Smoothing out the “edges” of the perfume can be done after a positive response.
Reverse engineering
Creating perfumes through reverse engineering with analytical techniques such as GC/MS can reveal the “general” formula for any particular perfume. The difficulty of GC/MS analysis arises due to the complexity of a perfume’s ingredients. This is particularly due to the presence of natural essential oils and other ingredients consisting of complex chemical mixtures. However, “anyone armed with good GC/MS equipment and experienced in using this equipment can today, within days, find out a great deal about the formulation of any perfume… customers and competitors can analyze most perfumes more or less precisely.”[17]
Antique or badly preserved perfumes undergoing this analysis can also be difficult due to the numerous degradation by-products and impurities that may have resulted from breakdown of the odorous compounds. Ingredients and compounds can usually be ruled out or identified using gas chromatograph (GC) smellers, which allow individual chemical components to be identified both through their physical properties and their scent. Reverse engineering of best-selling perfumes in the market is a very common practice in the fragrance industry due to the relative simplicity of operating GC equipment, the pressure to produce marketable fragrances, and the highly lucrative nature of the perfume market.