Presentation on theme: "Chemistry of Fragrance Ingredients"— Presentation transcript:
1Chemistry of Fragrance Ingredients Dr. William L. SchreiberChemlumina LLCMonmouth UniversityPresented at Fairleigh Dickenson UniversityNovember 7, 2006
2To be discussed What is a perfume? History Natural Ingredients Synthetic IngredientsChemical Process ExamplesResearch on New SyntheticsThe Science of Olfaction
3What Are Perfumes?Mixtures that are created for use in a wide variety of applications:expensive couturier perfumes, cosmetics, personal grooming products, laundry products, household cleaning products, air fresheners, candles, etc., etc., etc..From a palette of several thousand materials, most of which are manufactured by chemical processing methods.
4History of Perfumes5000 BC – Egyptian First Dynasty – earliest evidence3000 BC – Mesopotamia: extraction pots, early apparatus1400 BC – Book of Exodus “anointing with oils”370 BCE – Theophrastus writings on use of oils to make fragrances longer lasting.800 AD – Alembic distillation apparatus – Jabir ibn Hayyan1200 AD – Essential oils produced in pharmacies1600 AD – Quality of many natural extracts established1860 AD – First synthetics (naturally occuring materials)1900 AD – First non-natural synthetics (ionones, nitro-musks)
6What are Fragrance Ingredients? Odorants, Diluents and FixativesNaturals and SyntheticsChemicals having 6 – 18 carbon atoms (mostly), and usually one oxygenated functional group. There are also some multi-functional materials as well as a few sulfur- and nitrogen-containing chemical compound.
8Performance in Use Volatility Stability Function of molecular weight (how many carbons) and chemical type.StabilityFunction of chemical type and use condition (acidity, alkalinity, oxidizing, open, closed).Odor Threshold and dose/responseFunction of chemical structure (molecular shape and chemical type).
9Natural IngredientsMostly of vegetative origin, a few from animal secretions – largely replaced.Any part of a plant may be used: flowers, fruits, leaves, twigs, roots, wood.Synthetics have long overtaken naturals in volume of use.Naturals still very valuable and provide odor reference points for all materials.
10Types of Naturals Concretes – extracts with solvent removed Absolutes – concretes re-dissolved and filtered to remove waxes, etc.Essential oils – distillates, often with steam
28Research and Development AnalyticalApplication of new gc methods (head space with spme)Use of more sensitive and better computerized instrumentation: gc-ms, nmr, ft-ir.Live flowers – above methods used to analyze odors of flowers before picking.New extraction methods for naturals: supercritical CO2
29(often a combination of all three) Synthetic ResearchConsiderations:Structure – relationship to materials of known value – natural or syntheticRaw materialsProcess(often a combination of all three)
30Synthetic Research Practical only for largest companies. Hundreds of materials synthesized each year for evaluation.In-depth evaluation must include testing in fragrances and in applications.Decision to develop cannot be taken lightly.
31Development of New Synthetics Processes must be very well worked out in laboratory, pilot plant and factory.Best economics, safety and workplace hygiene.Testing is required to meet industry safety standards and international PMN requirements for all new chemicals.Cost to register new ingredients worldwide is well over $300,000.
33Smell and Taste are Chemical Senses In order to perceive smells or tastes, chemical substances must contact receptors in the nose or on the tongue.Perception is the result of the processing of signals from these receptors by the brain.
34Recent Developments1991 – Richard Axel and Linda Buck discover a family of genes that appear to be responsible for olfactory receptors.(received Nobel Prize – 2005)1998 – Stuart Firestein expresses a receptor from one of those genes and shows it responds to different odorants.2000 – Linda Buck shows that odor perception is based on combinatorial interaction of odorants with receptors.
35Combinatorial Odor Perception We have ~350 active odor receptors.One odorant activates multiple receptors.Each receptor binds multiple odorants.Perception of different odors results from distinct combinations of activated receptors.L. Buck, et. al., Cell, 1999.
38In Conclusion…Fragrance ingredients are a complex part of a the even more complex world of perfumes. Understanding what they are, where they come from and what they do is the key to making better smelling and better performing fragrances.Thank you for the opportunity to participate in your class this evening.