Aroma's Amazing Importance

We live in an age of abundance. Consumers have so many food choices today that a product's success or failure is based on consumers' preferences, not needs. In this environment, food companies need to strive for brands that connect viscerally with consumers to gain success, suggests Alex Moskvin, vice president of BrandEmotions, International Flavors & Fragrances, Inc. (IFF), Dayton, NJ.

"We are increasingly recognizing the importance of consumers' insights," Moskvin says. Brands need to speak to and connect with consumers emotionally. He notes that sensory branding is now five-dimensional, as we learn more about the role odors have in determining the desirability of our foods and beverages.

Much of the basic research to help us understand how we recognize and remember different odors or aromas has occurred in the last 20 years. This includes identifying the receptors in the nasal passage that detect odorants. The importance of this work was recognized by the Nobel Assembly at Karolinska Institutet, Stockholm, Sweden, when the institute awarded the 2004 Nobel Prize in Physiology or Medicine to Richard Axel and Linda B. Buck for the discovery of "odorant receptors and the organization of the olfactory system." In 1991, Axel and Buck jointly published a paper that described the very large family of about 1,000 genes for odorant receptors (Cell, 65(1):175-87). Since then, they have independently published several studies that clarify the olfactory system.

Recognizing aromas

The human olfactory system can detect and identify thousands of odorants. Our nasal passages are lined by the olfactory epithelium, a thin sheet of mucus-coated sensory tissue that contains millions of olfactory receptor cells. Each cell possesses one type of odorant receptor, and each of these receptors can detect a limited number of odorant substances.

Olfactory receptor cells are, therefore, highly specialized for a few odors. The human nose probably contains several hundred different types of olfactory receptors, while animals with a highly developed sense of smell--such as dogs, rats or cats--may have over 1,000 different receptor types, explains Leslie Stein, senior research associate, Monell Chemical Senses Center, Philadelphia.

When an odorant molecule binds with a receptor cell, it triggers a biochemical chain reaction that shifts the receptor cell's electrical charge. This shift causes the receptor cell, which is also a nerve cell, to fire off a series of electrical pulses to the brain. These pulses are received by glomeruli, tiny spheres where nerve endings gather in the olfactory bulb--the primary olfactory area of the brain. Each glomerulus receives signals from nose cells containing the same kind of receptor.

The hundreds of glomeruli resemble an electronic switchboard, notes Stein. Any particular odorant may activate several different receptors, which in turn causes the switchboard to "light up" in unique patterns. These complex patterns provide raw information for the brain to interpret. The olfactory bulb then processes these patterns and distributes the information to the rest of the brain.

An interaction of senses

While aroma is a powerful driver of food choice, a close association exists between taste, aroma and the trigeminal sensation--the three contributors to flavor. The trigeminal sense is an individual sensory system. Trigeminal nerve endings, located in the mucous membranes of the nose, and in the mouth and the eyes, measure characteristics described as hot, pungent or biting found in foods such as mustard, ginger, chiles and peppermint.

The human tongue can detect five basic tastes: salty, sour, sweet, bitter and umami (a savory-type characteristic of protein-rich foods). To identify a flavor, people use their olfactory system. A good example of this is beverages. Many beverages have only a sweet and acidic taste. We identify the characterizing strawberry or other flavor of the beverage through aroma.

Aroma sells the beverage, John Bedford, chief technical officer, Mastertaste, Rosemont, IL, points out. Once food enters our mouth, its olfactory information travels to the nose via the retronasal route, a passageway connecting the oral and nasal cavities.

The power of environment is also an important factor in food acceptance, Moskvin says. He notes that studies have shown that people don't eat as much in the dark. The sense of hearing also impacts brand choice. Magnetic resonance imaging shows people react differently to the same flavor, depending on what the flavor is called. For example, the response to an odor is different if a person is first told the flavor is wild berry, and then told the same flavor is fresh cherry, he explains.

Taste and smell are hard-wired, yet smell is a powerful driver that can evoke long-forgotten memories. Aroma's pathways to the brain are carved in infancy. By connecting to the senses, companies can evoke powerful bonds between products and consumers, Moskvin emphasizes.

Impacting flavor development

Advances in our understanding of how the olfactory system works is changing the way flavorists create flavors. Much of the research is now conducted on the molecular level, Bedford, points out. Flavor development used to focus primarily on identifying characteristic flavors in foods, such as fruits, cooked meats or baked breads. A large amount of work in this area has been done and is documented; current research is extending to how the body reacts to flavors and odorants, he adds.

Investigative studies are ongoing to find molecules that enhance some flavors and hide others. An example is the search to find molecules that bind to the taste receptor for bitterness to mask the bitter taste of ingredients, such as artificial sweeteners, green tea or botanical extracts. Some research also aims at identifying molecules that will fool the brain into thinking something is sweeter than it actually is. For example, a jamlike strawberry aroma can do this. This will open new markets for food companies, Bedford proposes.

Ongoing studies are also focusing on how to make flavors last longer by tailoring them to how the body functions, and by finding flavor notes that keep the brain activated longer. Normally, we become sensitized to flavors after exposure over time. Flavorists are searching for molecules and groups of molecules that have a longer effect, such as protein-containing and heavier molecules.

Combining the strong impact from lighter molecules with the longer-lasting impact from heavier molecules is an art, Bedford says. Finding flavors that are recognized by the brain for a longer time period can lead to product differentiation. This is especially applicable to gum and beverages. Each sip of a drink should have a revitalizing smell--without overpowering by the end of the drink, he adds.

Another area of interest is olfaction packaging technologies. Barry Edelstein, CEO, ScentSational, Jenkintown, PA, discussed an encapsulation system that incorporates flavors into food and beverage packages at the 2006 IFT Annual Meeting + Food Expo in Orlando, FL. Smell is increasingly recognized as a key factor in consumer decision-making. "Research shows that we are 80% more likely to purchase a product if we can smell it," he notes. "And approximately 80% to 90% of total taste experience is related to aroma."

One challenge is providing a consistent aroma due to the large number of olfactory receptors and the difficulty of delivering the aroma in a consistent way to the nose or through the retronasal passage. Aromatic compounds have a low boiling point and are volatile, which increases the challenge.

Yet people often choose a particular brand based on expectation of a guaranteed taste and smell, suggests Anton Angelich, group vice president, marketing, Virginia Dare, Brooklyn, NY. Aroma is a first affirmation that what you purchased is what you want and expect--before you consume the product. Products must pass by the nose before entering the mouth, he adds. People are wired to believe that if the appropriate aroma is identified, their taste expectations will be met. Based on each individual's personal history and preferences, food acceptance is a complex emotional process.

Creating flavors

Creating flavors begins with analyzing flavors in nature. The search for a fresh-picked strawberry begins in the field, where flavorists capture the strawberry's aroma in a tube for laboratory analysis. Since many fruits are picked before peak ripeness, flavorists still need to go to the field to capture the sensation of freshly picked fruit, Angelich notes.

Consumer expectations need consideration when designing flavor. For example, strawberry flavor from France tends to be floral in nature, while one from the United States is more jammy. In addition, flavorists put their own imprint on the flavor. A flavor doesn't have to be exact; there might be a spin--or fantasy--involved. In creating a flavor, we may want to go beyond the bounds of past experience, Bedford suggests.

Today's consumers are much more adventurous. An explosion of taste has occurred, with flavors such as "wicked" hot chocolate--with chiles and allspice--and "spicy carrot" ice cream gaining popularity. This is an exciting area, suggests Moskvin, adding that as technology advances, nature becomes more fascinating.

Ann Przybyla Wilkes is a freelance writer and communication consultant with more than 20 years experience writing about the food industry, environmental topics, and chemical issues. She has served as the vice president of communications for the Snack Food Association and has an M.S. degree in Food Science. Her e-mail is  [email protected].