The Time Is Ripe: Making Sense of Fruit Flavors

By Kimberly J. Decker, Contributing Editor

Fruit flavors have always been a hitwith young and old, among newcomers and native-born, and in everything from soft drinks and dairy to baked goods and barbecue sauce. But several factors have injected fresh vigor into the category, including a steady stream of immigration, interest in health and wellness, the seemingly daily revelation of the next superfruit," and Americas true favorite pastime: a ceaseless search for novelty.

With the proliferation of the Food Network and cooking shows, the Internet, food magazines, gourmet shops, and exotic travel destinations, American consumers are becoming exposed to many new foods, cooking techniques and fruits," says Anton Angelich, group vice president, marketing, Virginia Dare, Brooklyn, NY. Skilled flavor chemists can meet the challenge and match the taste of most new or unusual fruits."

High profile

Flavor chemists are the detectives and forensic analysts of the food industry. Hot on the trail of a mysterious new apple flavor, the analytical chemist would take it apart to the molecular level and would find a whole series of compounds in it," says Ed Krutal, manager of flavor development, Robertet Flavors, Inc., Piscataway, NJ. As a flavorist, you try to put those compounds back to rebuild the flavor, but on a much more concentrated scale so that one or two milliliters can flavor a gallon, as opposed to having to put in the mash of 20 apples. Youre rebuilding what nature has already built for you.

These investigations have yielded entire libraries of flavor fingerprints": the chemical profiles that flavor families share in common. So, we know that brown flavors like maple, roasted nuts, and burnt sugar, produced in caramelization reactions, are heavy in what Krutal calls sweet, brown-type chemicals." Savory reaction flavors generated by triggering the Maillard reaction in closed, concentrated vessels under high pressure and heat get their character from pyrazines, thiols, and sulfur-containing chemicals that smell like roast beef, chicken, or pork," he continues. Dairy, butter, and cheese flavors constitute yet another class, characterized by the organic acids found in cheese and dairy products.

A lot of fruit flavors use chemicals called esters," Krutal continues, which are very light and etherealfruity, really." In addition, the main core" of the fruit fingerprint includes sweet notes from maltol and furanones, virtually no pyrazines, and green notes from aldehydes and alcohols. So, in a banana, youd find isoamyl acetate," he says. Ethyl butyrate gives a light top note sometimes reminiscent of orange. You find ethyl butyrate in almost every fruit flavor."

Even among fruits, branches emerge whose organoleptic differences reflect differences in chemical composition. The sweet, flowery notes of ionones are typical of berries. If you smelled them individually," Krutal says, theyd give you that floral, almost perfumey character. And they fit well with raspberry and berry-type flavors, in addition to other chemicals that would round out the finished berry flavor." Benzaldehyde calls to mind cherry, and is the hallmark of other stone fruits like peaches, plums and apricots, as well as almonds. Stone fruits also display notes he describes as fleshy and pulpy," which flavorists recreate using lactones. They are creamy and dairy-like in their own right," he says. And if you go to the right structure, they have a little bit of a coconut character, also."

As for citrus, each has its own identifying components, but most are rich in terpenes, which, unfortunately, oxidize if left unprotected and give you off notes that people characterize as shoe polish," Krutal says. The compounds reside not only in the flesh, but in the peel, too. Tropical fruits are notorious among flavorists for their sulfur note, with mango lighter in effect than papaya or guava, and the durian attaining the stinky apotheosis. The chemicals responsible for these smells are useful to flavorists in building tropical profiles, but in a very concentrated, raw state," he says, theyre not fun to work with." Finally, pome fruits like apples and pears are heavy in esters. Depending on the varietal," he says, if youre looking for, say, and unripe Granny Smith, youd tend to use a lot of green alcohols and green aldehydes. So its all case-specific with the end product youre looking for."

Act your age

That manipulationturning up the green notes; dialing down the sulfur onesis the magic that flavorists work in shaping fruit profiles to appeal to, among other audiences, specific age groups. Palates evolve with experience and age, and a fruit flavor that may appeal to a toddler would likely strike a parents as flat, one-note and not very satisfying.

Childrens palates respond to flavors with a high impact of fruity or candy notes. For younger kids, we typically recommend simpler flavorsthose that are easy to identify, such as strawberry or banana," says Erin ODonnell, marketing manager, David Michael & Co., Philadelphia. Complicated blends for this group are a no-no, but fruit-and-cream pairings are always favorable." Once kids reach the tween years, their daring streaks kick in and they explore what she calls fantasy flavors, such as blue raspberry. Another example is dragon fruit," which although a real fruit, most children would probably recognize more as a fantasy fruit," she says. The tween stage is also when flavor blends become more acceptable, and when bolder notes start earning favornotably the super-sour burst of citric acid.

By the time kids officially hit their teens, fantastical fruit flavors are too childish," ODonnell continues. This is when children start moving toward more adult flavors, or even healthful flavors, such as pomegranate." Indeed, palates that have reached maturity appreciate healthy halos, as well as flavor authenticity.

To please adults, a fruit flavor has to be very true to the fruit," Krutal says.

Cultural studies

The question of authenticity also comes into play as communitiesand supermarketsdiversify. Immigrants from countries with rich fruit traditions have vastly expanded our notions of whats exotic" and what tastes like home. Yet, when it comes to pitching fruit profiles to mainstream versus ethnic groups, building a true-to-fruit flavor may take a back seat to pleasing the palates of the intended audience.

In my 30 years developing flavors, I have found that to appeal widely to consumers, flavors must be regionally relevant and taste good," says Brian Mullin, principal flavorist, Givaudan, Cincinnati. Not surprisingly, he singles out durian as a case in point. Calling it a very polarizing flavor," he believes that a typical North American consumer would find the flavor to be disagreeable and describe it as putrid, rotten or, at best, garlicky." For this market, durian authenticity is no virtue. Better to tone down the stinky notes and shunt the profile in a more obviously fruity direction. But for a Southeast Asian consumer, the real deal is just what they crave, making true-to-fruit durian flavors well-liked and found in numerous products," he says. A real-world success story in such cultural-catering lies in the arc that mango has traveled from fruit-bin oddity to prepared-food fave. When product developers some years back seized on mango as the next new fruit to feature in a popular line of ready-to-drink teas, they set the standard for American expectations vis-à-vis mango, choosing a milder, peachier profile than the true fruits. Prior to that," Angelich says, most Americans were not familiar with the taste of mango. However, tastes change, evolve and become more sophisticated, so it would be well worth a product developers time to create truer-to-fruit tastes and test them with consumers."

Winning teams

Another strategy for introducing unusual flavors to new consumers involves blending less-well-known fruits with familiar ones, Mullin says. You start with the known fruit and add the unknown fruit as a modifier. Consumers find the flavors appealing, and over time might be interested in the unusual flavor on its own." For years, mango rarely appeared in a product without apricot at its side. Similarly, kiwi rode into the spotlight on strawberrys well-known coattails.

These marriages werent merely of convenience, Mullin says. Rather, combinations like kiwi-strawberry and apricot-mango blend so well because the groupings contain similar-tasting molecules that complement or enhance the paired fruit," he explains. Apricot-mango works because the lactones in both flavors are similar and complement each other." Similarly, kiwis green components match those youd find in strawberry: C6 alcohols and aldehydes. And the melon-like components in kiwi lift the strawberry notesC9 alkyl dienalsvery nicely," he adds.

To draw a starker line between the two flavors, Krutal notes, you could shunt the strawberry component more in a jammy or ripe-fruit direction. But from a chemistry standpoint," he says, they fall very close to one another."

Yet, not all happy flavor marriages are cases of like paired with like. Take the initially odd coupling of strawberry-banana, which has become a classic yogurt and dairy profile. Another winner without a lot of obvious chemistry is blueberry and lemon. A blueberry is a floral berry," Krutal says. It sometimes has grape notes. But with lemonin lemonade, for instancethey just hit it off."

Flavors in action

Moving from flavor to application will always require some finessing. When a flavor is incorporated into a product application, the fruit flavor is now combined with the base product," Angelich says. A flavor applied to a smoothie beverage now has the combined dairy tastes of the smoothie dairy base and the fruit itself."

Krutal offers tea beverages as an ideal platform for fruit flavors. Tea beverages show fruit flavors well," he says. The same goes for lightly sweetened drinks in general. Theres not much going on except acid, sugar, water, color and flavor," he notes. Soft drinks display citrus flavors to good effect, though the flavors tendency to oxidize can be problematic. Again, we use that word, shoe-polishy," he says. Even in a finished carbonated beverage or in an acidified beverage, a lemon flavor may degrade over time and lose its lemon impact, because certain molecules are attacked by the acids and break down."

Dairy applications call on a different set of considerations. Now youre fighting the mouthfeel of any milk or soy base that would be in the product," Krutal says. Fat lends its own mouthfeel, and also may impair the palates ability to pick up a delicate flavorraspberry, for instance. So you try to add more flavor without distorting the profile," he says. You may have to rebalance the profile, building the flavor in order for it to come through and taste normal in a high-fat product." Flavor applications specialists may play around with sweetener and acid levels, but then again, that could work against you for certain flavors that do not work well with acid," he says, like banana.

In baked goods, the issue is choosing a flavor form thats compatible with the baking process. You can take any liquid fruit flavor and convert it to a spray-dried flavor, which is good to use in a dry-mix application," Krutal says. The effects of being spray-dried may even protect the flavor during the steam distillation that occurs as the product bakes. Now you have heat, water and volatile components," he explains, so youre doing a distillation on a very small scale, and before that flavor can be totally distilled off, it has to be solubilized by the available water in a baked-good matrix. So converting the flavor from a liquid to a dry powder also protects it somewhat, in addition to making it usable in a dry mix."

The temperature abuse involved in confectionery production is even more dramatic than in baking. You have hot-to-hot molten sugar," Krutal says, and putting a flavor directly into that environment, you have to hope that most of the flavor survives by the time you cool that candy down." For that reason, many candies fall back on artificial flavors, which are more reliably temperature-stable than natural. While advances in natural options are changing that, the flavors still have to be very concentrated with very little solvent, and used at fairly high levels," he says, to withstand the abuse that candies take.

No matter the application, the key message is to treat fruit flavors with care. You dont want to abuse them with overuse of heat or acid," Krutal says. Its a fine line between taking the necessary steps to get your product out there and also not abusing the product too much to where these delicate flavors may not survive."

Kimberly J. Decker, a California-based technical writer, has a B.S. in consumer food science with a minor in English from the University of California, Davis. She lives in the San Francisco Bay Area, where she enjoys eating and writing about food. You can reach her at [email protected].

Varietals: The Spice of Life

Part and parcel of the chase for authenticityand for evermore-stimulating fruit flavorsis the growing focus on varietal fruit character. A lemon cant just be a lemon; it has to be a sweeter, less-tangy Meyer to claim true foodie status.

Ed Krutal, manager of flavor development, Robertet Flavors, Inc., Piscataway, NJ, notes his company is developing a library of varietal fruit profiles. We just did a push on blueberries, mangos, peachestrying to get case-specific and do a donut peach, in addition to a white Asian peach," he says. The trick is locating that unique identifier that gives the varietal its distinct character. Its based on analysis and organoleptic evaluation. One varietal may have a very large peak or a chemical found in the analysis that puts it over the edge, and this is what you build around to make sure that people truly recognize it as that type of lemon or peach or whatever youre targeting," he says.

Brian Mullin, principal flavorist, Givaudan, Cincinnati, agrees. The most-interesting ingredients are those that have low concentrations in the food," he notes. These tend to have an important role in defining the fruit flavor. Large flavor houses are very good at finding major actives and minor ones that distinguish one varietal from another." What limits them is the availability of the relevant raw materials. The key components need to be GRAS, and there needs to be sufficient supply available," he notes.