SCIENCE & TECHNOLOGY AROMA NOTES Making fragrances often entails mixing and matching dozens of individual aroma chemicals, or ensembles of such chemicals known as accords. Bottles containing aroma solutions are to fragrance designers what musical notes are to musicians.
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IN PRAISE OF THE NOSE Fragrance designer Michael Papas philosophizes about perfumes and reveals what goes into them IVAN AMATO, C&EN WASHINGTON
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fragrance designer Michael Papas, and you will leave knowing that his father used to wear Old Spice and his mother used to favor the perfume Vanilla Fields. You will know that his seven-year-old daughter once abhorred taking showers but now loves to take them because of shampoos that smell like grapes and pineapple. As he informs you about these personal facts of his life, he also will show you what it takes to become more than the amateur smellers most of us are. At last month's national meeting of the American Chemical Society in Atlanta, Papas—who looks like he could be a cousin of Billy Joel's and speaks with an accent that would fit gracefully into any episode of "The Sopranos" (minus the profanities)—put on what can only be described as a four-hour fragrance design and philosophy performance. Home base for him is Quest International Fragrances' branch in Mount Olive, N J. W i t h the help of dozens of paper test strips labeled "raspberry," "rose," "herbal," "aldehyde," "vanilla," "lavender," "marine/ ozone," "bergamot," "patchouli," "nutmeg," "cinnamon," "ginger," "musk," and "sandalWWW.CEN-0NLINE.ORG
wood," among others, participants of this workshop-style presentation in the Division of Chemical Technicians' program got delightful whiffs of the aroma chemicals that designers combine in just the right proportions to create fragrances that can spin human emotions in specific directions. "From the time you get up in the morning to the time you go to sleep, smell is there," Papas reminded his audience, ticking off the toothpaste, soap, mouthwash, shaving cream, deodorant, breakfast, lunch, dinner, grass, leather, and myriad other odiferous items encountered during a typical day. W h a t you smell is just the sensory side of the fragrance experience. Says Papas: "Emotionally, you are experiencing positive or negative responses." Consider the fragrance-induced experience Papas had the morning of his ACS presentation. It turned out that the shower in his hotel room didn't work. To compensate, Papas admitted, he was perhaps a little more liberal than usual in the application of his Old
Spice deodorant. For Papas, Old Spice fragrance is a powerful reminder of his father, who passed away some years ago. "I put it on, and I am so connected to him," Papas told his audience. It is that evocation of an emotive and cognitive experience that fragrance designers aim for as they mix and match the aroma chemicals they have at hand, Papas says. Consider your doctor's office. Some physicians' offices use "vanilla plug-ins," fragrance-releasing devices that rely on gentle electrical heating to volatilize the fragrance. "People get nervous in doctors' offices," Papas says. "Vanilla is very comforting." Another example of a fragrance that has been designed to evoke a specific feeling is the Bobbi Brown perfume Beach, Papas noted. It smells like Coppertone sunscreen. That might not seem like a smell you would naturally choose for a perfume, Papas said, but "it's going for the feel of vacation. The emotive power of smell is important." Another nonintuitive approach Papas himself has been playing with in recent fragrance design projects has to do with dirt. "When people smell dirt, they love it," Papas said, drawing on consumer tests of potential new dirt aromas, or "notes," he has been working on. "They describe a dirt note as fresh, like a gardening smell. Dirt is clean to them." For example, two key notes here, cis3-hexen-l-ol and ligustral (6-isobutylquinoline), elicit thoughts of crushed leaves and cut grass, respectively. On the cognitive level, these aroma chemicals "can bring the outdoors into the house," Papas said. THE CONCEPT of "new-car smell" is one that Papas also has been revisiting. To him, a new-car smell shouldn't try to replicate the new-leather or vinyl smell of a car when it is just purchased. "I wash the car on the weekends, shampoo the rug, clean the dashboard," Papas said. "My car smells new after that. This is what I think people want, not leather." Most fragrances, whether they are the basis of fine perfumes or inexpensive scented candles, comprise three classes of aroma chemicals, often referred to as
From the time you get up in the morning to the time you go to sleep, smell is there."
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S C I E N C E & TECHNOLOGY top, middle, and base notes. Top notes, among them citrus aromas such as lemon, mandarin, and bergamot, are the most volatile components. They are the ones that hit you in the face when you open the package of a scented product, and they're mostly gone in about 20 minutes. Middle notes, including spicy, weedy, and leathery smells—among them eucalyptus, pine, men thol, rosemary, and sage—emanate over the course of a few hours. All the while, they mingle with the powdery, animally base notes, including musk, amber, cedar, and vetiver, derived from a tall Pacific Rim grass. In fragrances, base notes are the ones that last longest, sometimes all day. In all, fragrances can contain dozens of specific aroma chemicals. A fragrance designer also has to con sider the mode of delivery. Compared with perfumes applied as liquids, for example, aerosol products and candles have less of a need for volatile, top-note aroma chemi cals. In these cases, aerosolization and heat provide physical assistance for getting the aroma chemicals into the air. Fragrances for products like these, then, are often heavy on the middle notes.
NOSEY GUY Fragrance designer Papas holds a test strip bearing a cucumber scent as he explains how to create a fragrance.
Experts
The smell of the aroma chemicals them selves, whether extracted and isolated from natural sources or synthesized, is but one of the many factors that perfumers must weave into an affordable commercial bal ance. Among these are stability, pH, solu bility, viscosity, foaming properties, the physical phase of the products, precipita tion behavior, interactions with packag ing materials, social and marketing trends, costs, and cultural differences in respond ing to smells. "Safety is kicking in big time," Papas added, referring primarily to the growing concern about toxic ingredients in prod ucts. Perhaps reflecting that reality was the presence in the audience of three employees from the National Institute of Occupational Safety & Health. One of them insisted to C&EN, however, that he and his colleagues were attending Papas' talk not to find op portunities for imposing new regulations but to learn more about how the fragrance industry works. In the end, Papas said, "you can have great scientific data, but human perception is more important." The equation by which fragrances win or lose is so complex that Pa-
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A n even newer candle frapas often relies on his own gut grance that Papas created for feelings for making decisions. S . C . J o h n s o n , Cafe L a t t e , "More people should use their r e q u i r e d r e s e a r c h t h a t ingut-feel," h e told his a u d i cluded many hours in coffee ence, opining that too many shops. T h e goal was to create people forget t h a t t h e y are a fragrance t h a t evokes the expert at making judgments comfortable, lazy, untroubled and instead defer to so-called feeling of sitting in a coffee professionals. house and treating yourself to O n e of Papas' home runs as pastries and some Java. W h a t a fragrance designer emerged came of this effort is a twofrom a request by one of his pronged candle fragrance that primary clients, S.C.Johnson mixes a coffee fragrance with & Son of Racine, Wis., for a o n e r e m i n i s c e n t of p o u n d fragrance t h a t captures t h e cake. "This is more than just "extreme freshness of clean coffee," Papas said. "It's the sheets drying outdoors in the coffee house experience." brilliant s u n s h i n e . " O v e r a four-month period a fewyears NOVICE SNIFFER Chemical technician Eve Bauer of Los A m e a s u r e of g r e a t sucago, he concocted a half-doz- Alamos National Laboratory samples one of the dozens of aroma cess for a fragrance is when it en "accords," which are small chemical test strips that were part of a one-man symposium on takes on an iconic and posie n s e m b l e s of t o p , m i d d l e , fragrance design at the recent ACS meeting in Atlanta. tive m e a n i n g in a c u l t u r e . and base aroma notes. T h e y "Pine Sol smells like a janitor," have names like "airy accord," "transparent Clean Linen. O f the 2 0 or so Glade candle Papas noted, adding that it smells nothing floral accord," "clean accord," and "citrus products t h a t S.C.Johnson sells, t h e one like natural pine. "But people want it.... It's accord." T h e n , with t h e help of consumer with the clean linen scent is selling best, aca functional odor that smells like 'clean.'" focus groups, he found a combination of cording to J o h n J. Conlon of S.C.Johnson's A smell like that, Papas said, "you just don't these accords that has been trademarked as Air Care division. mess with." •
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