Pop Art

  The original sodas were mixtures of carbonated water and fruit extracts or syrups. Each pharmacist had his own recipe, which probably precipitated the industry's rapid and expansive growth. The current U.S. bottling system grew out of a system in which a soda inventor provided his extracts to bottlers in franchise agreements. These days, two major systems exist: company-owned and independent bottlers. No matter which system is used, flavors are usually sold as concentrates by the brand-owning company to the franchise bottler. The bottler mixes the water and sugar with the concentrates and other unit packs, which may contain the acid or other secret ingredients that make up the beverage.

  Today, a typical soft drink formulation includes water, sugar or other sweetener, acid, color, preservative and flavor, either in the form of an extract or as an emulsion. Juice may be added, usually in the 5% to 10% range. Caffeine also might be present, either naturally or by addition.

  Beverage production begins with the syrup. Rarely will a bottler batch up a finished beverage. To prepare the syrup, the production staff dissolves the sugar or high fructose corn syrup (HFCS) in part of the water. The preservatives are then added, followed by the juice (if present), finishing up with the acid, color, flavor and/or emulsion. Once the syrup is brought up to volume with the remaining water, the Brix and acid are checked and adjusted as needed.

  Each bottling plant has its own syrup ratio, or "throw." Originally, one part syrup was added to five parts carbonated water to create a 6 oz. bottle. Now, any combination imaginable is possible. Odd combinations, such as one part water to 4.67 parts syrup necessitate 53 ml of syrup for every 300 ml of finished beverage, a potential headache in the lab.

Water, water everywhere...

  Most water is treated at a local water-treatment facility where microorganisms, soil particles and other substances are removed or reduced to an acceptable level. Although municipalities maintain a safe drinking-water supply, they cannot be relied upon to ensure the uniform and consistent quality required by beverage manufacturers.

  All drinking water is monitored by state regulatory agencies, who follow Environmental Protection Agency guidelines. This requires that levels of all organics, pesticides and toxic or heavy metals comply with the Safe Drinking Water Act. However, the act does not require drinking water to meet beverage specifications for chlorine, sulfates and alkalinity. At the bottling plant, chlorine -- which is added during disinfection to help "purify" the water -- must be removed, or it will prove deleterious to flavor. High levels of minerals, such as iron and copper, also can affect beverage flavor, and must be kept below a specific level. Highly alkaline water adversely affects flavor and stability, so the pH of the water is adjusted by removing calcium and magnesium carbonates.

  In an effort to "get back to nature," many bottlers, especially those of New Age beverages, are using "pure spring water." As this water has not been processed by the municipality, it contains no added chemicals, but extra care must be taken to remove impurities and microorganisms such as bacteria, yeast and algae.

  Water purification methods include membrane treatment (reverse osmosis, nanofiltration and ultrafiltration), conventional coagulation and ion exchange. In addition to chlorination, disinfection can be accomplished by ozonation and ultraviolet sterilization. Together, both processes rid water of the pathogens E. coli and cryptosporidium, which are recognized public-health risks.

Sweet treat

  Originally, granulated sugar represented the sole sweetener used in the U.S. soft-drink industry. But when corn processors began experimenting with ways to convert starch to sugar, HFCS was born. Using HFCS 42 or 55 is more economical than cane sugar, and HFCS soon replaced granulated sugar in most beverages.

  "Both of these are high-quality stable ingredients," says Mark Hanover, director technical services, A.E. Staley Manufacturing Company, Decatur, IL. "High quality in terms of purity; they're refined or ion-exchanged, so they are extremely pure. They're clear. They're microbially stable.

  "Once the technology became available to convert the dextrose to fructose, it allowed us to make a product that is chemically equivalent to invert sugar," Hanover says. "That gives high fructose a parity sweetness with sucrose."

  HFCS 42 is 42% fructose, which is evaporated until it contains 71% solids. In some finished products, the sweetening power of HFCS 42 fell short, and HFCS 55 was developed to address this need. This product, the most commonly used, contains 55% fructose and is further evaporated to contain 77% solids.

  "The HFCS 42 can work especially well in the allied flavors, the non-cola beverages," Hanover says. "Most of these are flavored with the organic acids, not phosphoric acid like the colas. Phosphoric acid creates a harsher flavor, so it requires a higher fructose content to counteract it, and make it sweeter. The HFCS 42 will have a relative sweetness of 92, but if you put in a little of what we call a 'penalty Brix,' a little higher solids, the difference pretty much disappears."

  Since all sweeteners provide different sweetening power, beverages must be formulated to attain the same sweetness level as sugar. For example, when using HFCS 42, calculating the sweetness equivalence on a dry solids basis, 10% more HFCS 42 than granulated sugar must be used. Although the sweetness might be perceived as being the same, the flavor may be slightly different.

  Syrup color is important, even in colas, because it can indicate product degradation, Hanover says. "With a very dark syrup, you can have some flavor development -- some of the bitter notes of a burnt sugar syrup."

  In addition to solids, color and clarity, corn sweeteners have other factors that affect their usage. One is the presence of acetaldehyde. This compound may occur as an artifact of the syrup manufacturing process, and can affect the long-term flavor stability of cola. The industry and its customers have placed stringent limits on the level of acetaldehyde allowed in HFCS, which has eliminated the earlier flavor problems.

  For sweetening, some beverages use crystalline fructose, the sweetest of all naturally occurring sugars. It can offer some flavor-enhancing effects or sweetness synergies, as well as contribute to a reduced caloric content, because a lower level can produce equivalent sweetness. "High fructose is used in a cola beverage at a level of approximately 11% solids," Hanover says. "You can get the same sweetness with crystalline fructose at 8% or 9%, or at 7% to 8% if you blend fructose with sucrose to take advantage of the sweetness synergy between the two."

  Fruit juices can sweeten soft drinks, and certain types also may contribute color and flavor. Pear, white grape and some types of apple juices tend toward the bland and colorless, while cranberry juice, for example, will likely make its presence known.

  "Another concern with juices is that they can contain other components that may settle out, such as pectins, when interacting with other components, especially alcohols or beer malts," points out John Cavallo, Ph.D., director of beverages at H&R Florasynth, Springfield, NJ. "In order to minimize that, you would want to look at depectinized juice and/or clarified juice."

  Diet drinks contain high-intensity sweeteners, also called artificial or nonnutritive sweeteners. Some of these are natural substances which have nutritive value, but are used at such low levels that they only contribute a minute amount to the total calorie count. Although they add sweetness, most of the intense sweeteners do not contribute to the physical properties of the beverage, such as viscosity or solids content, nor do they provide texture in the form of mouthfeel.

  The oldest intense sweetener, saccharin, was discovered in 1879, and is considered to be 200 to 300 times as sweet as sucrose. It would be some 55 years before another artificial sweetener, cyclamate, would appear on the scene. Cyclamate can be found either in the sodium or calcium form and is 40 to 60 times as sweet as sugar, depending on its beverage application. The United States banned the use of cyclamate in 1969 due to its alleged role in the development of bladder cancer in rats. However, many other nations have continued to allow the use of cyclamate. Aspartame, a dipeptide derived from the blending of L-aspartic acid and the methyl ester of L-phenylalanine, was discovered in 1965. While its sweetening power is similar to that of saccharin, it lacks the bitter aftertaste and the suspicion of carcinogenicity.

  Various nations have approved the following sweeteners for use in the nonalcoholic beverage category, but they have yet to gain U.S. approval:

• Sucralose, a derivative of the sucrose molecule, possesses a profile most similar to that of sucrose. It is 600 times as sweet as sucrose and, although it does have a lingering aftertaste, it is not unpleasant or bitter.
• Acesulfame K, the potassium salt of 5,6-dimethyl-1,2,3-oxathiazin-4(3H)-one-2,2 dioxide, is 200 times as sweet as sucrose. At high levels, it can impart a bitter taste.
• Alitame, a protein-based sweetener, is composed of 205 more amino acids than aspartame, and it is 2,000 times as sweet as sucrose.
• Stevioside, a natural substance extracted from the leaf of a Paraguayan plant, can range in sweetness perception from 100 to 300 times that of sucrose, and produces a bitter, sometimes astringent, aftertaste.
• Thaumatin is 100,000 times as sweet as sucrose. It is isolated from the fruit of a plant found in the rain forest of western Africa. The current U.S. maximum level in soft drinks is 5 ppm, a level that provides excellent flavor modification, but not sweetness.
• Neohesperidine DC is 1,500 to 1,800 times as sweet as sucrose and, like thaumatin, provides flavor enhancement or modification. At high levels, those where sweetness is detectable, both sweeteners have a slight licorice flavor. Neohesperidine DC offers the added benefit of increasing mouthfeel perception.

  Blending various sweeteners results in synergies that enhance the sweetness profile of beverages, as well as reduce the total amount of sweetener required -- a benefit from regulatory and financial points of view. In addition, combining sweeteners can increase shelf life of the sweetening system, especially when using aspartame, which loses some of its sweetness during long-term storage in an acidic product.

  Combining different sweeteners has the added advantage of reducing bitterness, while mimicking the sweetness profile of sucrose. Saccharin, acesulfame K, cyclamate and stevioside all benefit from the synergistic blending of sweeteners, due to their slightly bitter aftertaste.

  "We see many artificial sweetening systems developing," says Hans Peter Voss, vice president, beverage business unit, Wild Flavors, Inc., Cincinnati. "The challenge for the flavor industry is to design flavor systems around them to compensate for some of the deficits in flavor. If you use the same flavor for an artificially sweetened beverage that you do for a sugar-sweetened product, the sweetener will change the flavor profile. It will also change the physical effects."

Monitoring those microbes

  Classic soft-drink spoilage occurs four to six weeks after production, long after the product has been released into distribution. Overt signs of spoilage include sedimentation, cloud formation, presence of an odor or an increase in carbon dioxide due to fermentation. To ensure all microbiological risks are kept to a minimum, the product must be formulated to be robust. Product robustness is a measure of its resistance to spoilage. The more hurdles that can be designed into the product to help increase robustness, the less likely it is to spoil. Keeping the pH low, increasing the carbon dioxide level, adding preservatives, and processing with heat, all will add to product robustness, no matter how poor the raw materials or adverse the manufacturing conditions.

  It is rare for a product to be completely microorganism-free. The presence of microorganisms is tolerated, provided they remain below a specific number and do not "go forth and multiply." Yeasts are more often the source of soft-drink spoilage than bacteria or mold; Zygosaccharomyces bailii and Saccharomyces cerevisiae are found in juice-containing soft drinks while Candida babiani and Brettanomyces naardenensis are common to nonjuice products. Soft drinks are usually protected against pathogens, as they won't grow in high-acid environments, and mold won't grow in the presence of carbon dioxide.

  Raw materials, such as caramel color, juice and liquid sugar, often are sources of contamination. Caramel color contains nitrogen, an important growth requirement for microorganisms. Juices are normally preserved or heat-treated, then frozen or packaged aseptically to minimize introduction of microbes to the beverage. Even so, adding exotic juices such as mango and passionfruit decreases product robustness, while difficult-to-ferment lemon and lime juices do not.

  "As soon as you use juice, pasteurization or hot filling is recommended," Voss says. "There are new trends in package technology -- some European companies are working on cold aseptics, but I'm not aware of anyone currently using it in the U.S."

  Yeast also can be introduced to the product through liquid sugar; high fructose corn syrup does not pose as much of a contamination risk. Other sources of nutrients that support growth are hard water and some vitamins. Some ingredients, such as d-limonene (found in some citrus oils), deter microbial activity.

  Benzoic acid and sorbic acid are added as their sodium and potassium salts. These substances should be fully dissolved and added to the unacidified syrup to avoid flocculation. Benzoate and sorbate work best at a lower pH; the acid prevents the dissociation of the ions, thereby increasing their effectiveness. Each preservative works best in a specific pH range. Benzoate is most effective between a pH range of 2.5 to 4.0, while sorbate is effective at a pH up to 6.5. Preservatives are not meant to kill the offending microbes, just to keep them at bay. In fact, some strains are becoming preservative-resistant. Zygosaccharomyces bailii can be found in up to 1,200 ppm of benzoate.

  The major acids used in soft drinks are citric or phosphoric. Both control pH and balance the flavor. Citric acid is found in fruit beverages, while phosphoric acid is used in cola, root beer and cream soda. Malic, fumaric and tartaric acids have served as flavoring agents from time to time. Ascorbic acid is used more for its antioxidant properties, although in the nutraceutical category, the antioxidant effect is for the human and not the beverage, says Paul Kim, Ph.D., senior beverage technologist at H&R Florasynth.

  Each of these delivers a distinctive taste, which, in turn, affects flavor delivery. "If you are working with a malic acid base and then change to a citric acid base, you'll get something different," Cavallo says. "If you are working with a specific flavor like grape, you want to use a compatible acid."

  "In cranberry, you'll probably find a combination of malic and tartaric," Kim says. "In grape, it might be tartaric. In apple, it would be malic."

Flavors galore

  With natural flavors, things like stability and cost come into play, "but they're not prohibitive factors," Cavallo says. "One of the main factors is the availability of the natural component to formulate a natural flavor. In the U.S., the New Age beverages tend to be based on natural flavors."

  Soft drinks typically fall into two categories: clear and cloudy. Clear beverages, such as lemon-lime, require water-soluble flavors. Since most natural flavors begin as oils, which are not water-soluble, they must be processed to achieve solubility in an aqueous beverage. To do this, flavor oils are thoroughly mixed with alcohol and water and allowed to sit, eventually separating like homemade salad dressing. During this process, flavor components -- typically the oxygenated portions which are less hydrophobic -- migrate to the water phase, resulting in two flavoring agents, an extract and a washed oil. The extract is then used to flavor the beverage.

  Flavor oils, whether distilled, cold-pressed or washed, are components of flavor emulsions. In addition to the oils, most emulsions also contain stabilizers, emulsifiers and/or weighting agents. Preservatives, such as BHA or alpha tocopherol, can also help extend shelf life of the emulsion. Citric acid also is added to adjust the pH.

  Flavor emulsions, which are oil-in-water emulsions, have two functions. The major reason to add a flavored emulsion is to impart a cloud; this enhances the appearance of the beverage, making it look more natural. The second reason is adding flavor, since oils hold an advantage over extracts. The flavor is much more complex, providing an increased natural character and depth of flavor.

  "Whenever you want to impart turbidity, you would introduce a cloud," Voss explains. "This is important in juice-containing products or products that are similar to juice-containing products. It reinforces the concept of juice. The clouding agents can influence the flavor or taste. You have to increase the flavor level or work the flavor around the cloud."

  While many emulsions contain the flavor of the finished beverage, neutral clouds also can be used to impart a hazy character. In this case, the flavor is added to the beverage separately or as part of the juice concentrate.

  Because of their composition, flavor emulsions also impart a richer mouthfeel, Kim says. "While you can get benefits from an emulsion, it has to be a perfect balance. Otherwise, if it's in a clear bottle, exposed to sunlight, you'll witness some ringing -- the emulsion will break down and form a ring around the neck or even some sedimentation on the bottom of the container."

  "All emulsions will eventually break down," says Cavallo, "but the secret is to balance them so that the separation point is as far in the future as possible."

  "There are many factors to be aware of when utilizing clouds or emulsions," adds Kim. "Types of emulsions, emulsifiers, oil phase, and various processing conditions, as well as the beverage system in which the emulsion will be used, affect stability. The stability of the emulsion concentrate is as important as the stability of the emulsion in the beverage. Overmixing can be a concern as well to stability."

  Fruit-flavored products, especially citrus products, normally contain oils from the various fruits, such as orange, grapefruit, tangerine, lemon and lime. Lemon oils, like most of these oils, are composed of three classes of chemicals. The first are the monoterpene hydrocarbons, primarily d-limonene. The second are the oxygenated components: the alcohols, esters and aldehydes. Two important aldehydes are neral and geranial, collectively known as citral. The third group comprises the sesquiterpene hydrocarbons, such as bisabolol and caryophyllene. These compounds together contribute to the characteristic flavor of lemon. The nonvolatile components of lemon contribute most to the characteristic flavor and mouthfeel of the native fruit. Specific components, if isolated, would impart noncharacterizing notes. This would allow each of the oils, or its components, to be added in discriminating quantities to other flavors, creating distinct and proprietary flavor blends.

  For example, linalol and beta-pinene, which are both found in lemon oil, have a lavender and a pine note, respectively; terpinene, found in lime oil, has a eucalyptus note. Clove oil, thought to be quite spicy when used alone, is found in extremely small quantities in banana and blackberry flavors, rounding out the flavor without being noticed individually. Other lesser known oils also are used to make fruit flavors. Buchu leaf oil imparts a catty note essential to blackcurrant -- a popular flavor in the United Kingdom and other European countries.

  Orange is quite similar to lemon, even to the point of containing many of the same flavor chemicals. The minor flavor components are the most characterizing so they create quite different flavors with seemingly small differences in the levels. "Orange is orange" is an untrue statement. All the varieties and species, sweet orange to bitter orange to tangerine and mandarin, contain their own proprietary blend of oils distinguishing themselves from one other. By blending each unique oil, a huge variety of orange flavors can be created. Orange and, to some extent, lemon are added to other fruit flavors to increase fruitiness and round out the flavor.

  The major components of colas are citrus blends, spice blends, vanilla extract and kola nut extract. The individuality of the cola is a result of the specific blends. A citrus blend, typically strong in lime oil, can be altered so that lemon is more prominent. Spice-oil blends can contain oils from cassia or cinnamon, as well as clove, nutmeg, cardamom, coriander, ginger and pimento berry in varying quantities and ratios.

  One of the areas currently receiving a high level of interest is premium root beer, Cavallo says. "As a spin-off of the microbrewed beers, these products are highlighting aspects like high-quality vanilla profiles, creaminess and texture attributes."

Mix it up

  The best way to get the two to mix is by altering the specific gravity of one of the components. The essential oils are usually chosen, as they contribute only a minor percentage to the finished product. When the oil phase of the emulsion is prepared, the weighting agent is added and thoroughly blended, thus raising the specific gravity of the blend. Brominated vegetable oil (BVO) makes an ideal weighting agent, due to its high specific gravity. Brominated cottonseed oil has a specific gravity of 1.33, which easily can bring the total oil-phase specific gravity up closer to 1.0. To work effectively, approximately 120 to 150 ppm of BVO is required in most beverages. Unfortunately, in 1970, BVO was restricted to 15 ppm in the finished beverage, because bromine is considered a carcinogen. In the United States, ester gum has become the primary weighting agent. In Europe, combinations of elemi resin, rosin resignal and dammar rosin are used, and ester gum recently gained European Union approval.

  Increasing the specific gravity of the oil phase represents only half the battle. Once the oil and water phases are mixed, they require additional help from a stabilizer. Gum tragacanth was used as a stabilizer until gum arabic (gum acacia) arrived on the scene. More than 600 species of gum acacia exist. Different nations' regulatory bodies define gum acacia differently. Most agree that the most important commercial species is Acacia Senegal L. Willdenow or related species from the family Leguminosae.

  Significant amounts of gum acacia (18% to 22% weight/volume) must be used to stabilize the emulsion and, ultimately, the finished beverage.

  Specialty gums manufacturer Colloides Naturels Inc., Bridegewater, NJ, has developed "second generation specialty blends, which have an economic advantage over pure spray-dried gum acacia with the same stability," says Brent Lambert, vice president, Colloides Naturels Inc. "If you use 20% standard spray dried gum acacia, you need to use only 5% Emulgum(r). While (pound for pound), Emulgum costs more than spray-dried gum acacia, the cost/usage ratio is much cheaper than standard spray-dried gum acacia. And it is also cheaper than starches." According to Lambert, the finished beverage "can go as long as two years without a break in the cloud or emulsion."

  Starch also can make an economical alternative to spray-dried gum arabic. National Starch and Chemical Company, Bridgewater, NJ, has developed a product derived from waxy maize, Purity(r) Gum 1773, to replace gum arabic in flavor emulsions. It is cold-water soluble, and displays very good viscosity stability. Usage level is 12%, which is two-thirds of the recommended spray-dried gum acacia level. It is typically used with equal parts flavor oils.

  Emulsion particle size is another consideration. Smaller particles are less likely to coalesce and create large particles, which rise to the top and cause a bottleneck ring or sink and produce a sediment. The smaller the particle, the greater the chance they will stay suspended in the water phase of the emulsion and the finished beverage.

  Once the two phases are mixed together, the types of preshear equipment and stabilizer will dictate the pressure and whether a single- or double-stage homogenization is warranted. The number of passes through the homogenizer also is negotiable. Typically, the less processing, the better, as a lesser chance exists of damaging the stabilizer.

  Other gums and starches can help control viscosity or enhance mouthfeel, particularly in diet beverages. Guar, locust bean and xanthan all can be used to adjust the viscosity. At lower levels, they increase mouthfeel; at higher levels, they can help mimic the viscosity of shake-type beverages, especially in the meal-replacement/nutraceutical category.

  In Japan, the bulking agent polydextrose is approved in beverages to increase viscosity, while also providing a source of fiber.

Color forms

  Certified colors, the official name for colors known as FD&C, are synthetically produced from purified chemicals. Certification means that a particular batch has been tested by FDA and complies with the purity specifications as set by 21 CFR Part 74.

  The FDA has approved seven water-soluble, synthetic dyes for use in food products: Blue #1, a turquoise blue; Blue #2, a deep blue; Green # 3, a bluish green; Red #3, a deep pink-red (bluish in solution); Red #40, an orange red; Yellow #5, a lemon yellow; and Yellow #6, an orange yellow.

  Many non-brown beverages use these colors because they provide exceptional stability at low cost, particularly with transparent packaging.

  "Even synthetics may have some light-stability issues," says Penny Huck, associate director of technical service, Warner-Jenkinson Co., Inc., St. Louis, MO. "The shelf life really depends on the product being colored and the exposure issues. For example, if a convenience store puts clear bottles out in the sunlight in the middle of summer, you can even see some changes with the FD&Cs."

  Twenty-six colorants typically referred to as natural are defined by FDA as "exempt from certification" and are listed in 21 CFR Part 73. These are obtained from various plant, animal or mineral sources. In addition, fruit juices that contain anthocyanins (such as cranberry or elderberry) also can color beverages. Some of these products also may carry slight flavors, but the effect depends on the usage level. For example, red cabbage juice is used for pink lemonade, without any discernible effect on flavor.

  "Many still, or New Age, beverages use natural colors," Huck says. "Oil-soluble colors, like beta-carotene, require special processing to make them water-dispersible for beverage applications. It can be added separately, or some prefer to homogenize it with their own flavor systems."

  Ringing can occur with beta-carotene and other oil-soluble colors, especially paprika extract, but certain ingredients can help alleviate this, including fruit-juice solids and pectins that help keep the color in suspension. "Using glass bottles will also help with ringing. Because of the hydrophobic nature of PET, it promotes the attraction of naturally oil-soluble beta-carotene, which breaks out of emulsion and 'rings' at the top," notes Huck. "PET can also allow the transmission of oxygen, and that can destabilize some of the natural colors."

  Some colors, such as cochineal extract, a natural orange/red magenta colorant, are very stable in beverages. On the other hand, turmeric or annatto are rarely used because of their light sensitivity. The low pH environment of beverages can be a plus -- most of the anthocyanin-based colors only exhibit a bright red color in an acid environment.

  Caramel color is the most frequently used natural color in this application, due to the popularity of colas. It also can be used in root beer, iced tea or coffee beverages. Most beverage formulations use liquid caramel color, which saves on ingredient and labor costs.

  "Most people use a single- or double-strength acid-proof caramel color," says Chuck Sethness, president, Sethness Products, Co., Skokie, IL. "Today, it's mostly double-strength, which was initially developed for diet drinks to keep the caloric value of the finished product down. But most people have switched to it because of the cost economies."

  Typically, standard products suffice. But in some cases, custom caramel color will be required. "One manufacturer may want a low-sodium product, another may specify a slightly different pH," Sethness says. Depending on the required finished hue, different products are available that range from golden tints to ones with darker, blacker tones.

What's the buzz?

  Caffeine is a natural compound found in colas, which contain kola extract. It is regulated in the United States, and up to 200 ppm or 200 mg per liter of beverage in cola-type beverages is allowed. The U.S. government recognizes a broad interpretation of this regulation, as it is found in many different beverages. The range typically found in most soft drinks is 50 to 100 ppm, although a few "jet fuel" type colas take it to the max. Keep in mind that coffee naturally contains up to 300 ppm of caffeine. Even water, the original soft drink, has been formulated recently to include caffeine.

  Nutraceutical, New Age and herbal beverages often add caffeine in the form of guarana, a Brazilian herb. This herb's flavor comes across as "earthy, almost a mushroom character, and it even has some metallic characteristics" according to Kim.

  "That character varies, according to the way the extract is made, and whether other flavors are added," Cavallo says. "Not everyone has the same expectation as to what the flavor actually is. Often, the best way to introduce the flavor profile of these extracts is to make it more recognizable or to mask the objectionable part of the profile with more recognizable flavors."

  Other trendy ingredients can present flavor difficulties, depending on the target market.

  "If you have developed a soft drink based on green tea for the Asian market, it can be pretty close to the original green tea taste," Voss says. "With a very low sugar, it can be very bitter. For the European market, you would need to blend it with other flavors, like lemon or fruit juices. That would give a pleasant-tasting beverage with the functional properties of the green tea."

  Herbal beverages and those containing functional ingredients such as ginseng, chamomile or ginkgo also are rising in popularity, according to Cavallo. In addition to flavor issues, manufacturers can run into problems communicating the benefits that drive purchase interest. "Because the FDA limits the claims you can make, a lot of these products lend themselves to be formulated with ingredients that already have a certain level of consumer awareness, like beta-carotene," says Cavallo.

Tiny bubbles

  Carbon dioxide is added to the beverage in one of two ways. Either the syrup and water are mixed in the proper finished beverage proportions, and then passed through a carbo-cooler prior to bottling, or the water is first mixed with the CO2 in the carbonator, and then mixed with the appropriate amount of syrup in the bottle. In either case, the liquid passes through a deaerator prior to carbonation to remove as much oxygen as possible from the product. This increases beverage stability and shelf life, and minimizes foaming during filling.

  The amount of CO2 absorbed by the liquid, either water or finished beverage, is a function of temperature and pressure. The colder the liquid and the higher the pressure, the more CO2 it absorbs. Carbon dioxide is measured in volumes. One volume is equal to 14.7 lbs. per square inch (psi) pressure at sea level and at 60º F. Soft drinks can contain between one and five volumes of CO2, which is between 14.7 and 73.5 psi. Ginger ales, mixers and colas typically contain the highest amount of CO2, ranging between 3.5 and 5.0 volumes. The lemon-limes and root beers contain between 2.5 and 3.5, while the fruit carbonates contain less than 2.5 volumes.

  In the United States last year, consumers spent more than $53 billion on soft drinks at soda fountains, convenience stores, grocery stores and discount clubs. They purchased name brands as well as store brands in cans, glass bottles or PET bottles in sizes ranging from single-serve 12 oz. units to family-size 2-liter packages, accounting for one-quarter of U.S. beverage consumption. Those tiny bubbles just keep rising to the top of Americans' drinking habits, and the well-equipped, well-informed food product designer can ride the upward-bound carbonated path as well.

Bubble-ology 101

  Soda water, one of the original products in the Schweppes lineup, consisted of water charged with carbonic acid to which soda (sodium salt or sodium carbonate) was added. This, as well as other alkaline waters (soda water, seltzer water and spa water), were quite popular among Europeans during the late 1700s and early 1800s. Variations of these soda waters also were found in America, although sometime around 1830, "soda water" became synonymous with any carbonated water regardless of whether it contained soda. The first recorded instance of a soda water sale in the United States occurred in New Haven, CT, in 1807 by Benjamin Silliman. The term "pop" or "soda pop" didn't join the American vernacular until the early 1860s.

  It would not be long before flavors would be added and carbonated water would be consumed for pleasure. Lemonade, long a refreshing still drink, was carbonated and sold as Aerated Lemonade in 1835 by J. Schweppe & Company, beginning the long journey to today's complex soft drinks market. Another citrus-based product, Quinine Tonic Water, was first bottled by Erasmus Bond in 1858 in Britain. Tonic water, a byproduct of the British Raj's need to ward off malaria, has its origins as a medicinal beverage, but made its way back to Britain from India, its popularity due to its taste and compatible blending with gin.

  By 1865, at least 15 different soda flavors were being sold in the United States. Vernors, a spicy ginger ale, was the first flavored soda to be bottled, debuting in 1866. Hires Root Beer was developed in 1870, although it would not gain prominence until six years later. In 1871, the first soft drink trademark was issued in Canada to a company that would ultimately become the Canada Dry Company for Lemon's Superior Sparkling Ginger Ale. A readily recognized brand today, Coca-Cola was first bottled in 1894, but was sold for eight years prior at a pharmacy soda fountain. Pepsi-Cola, trademarked at the turn of the century, also began as a soda fountain drink. The unusual-tasting Dr Pepper arrived in 1885. The first orange flavor, called Crush Orange, was bottled in 1916. Seven-Up, originally caramel-colored and called Bib-Label Lithiated Lemon-Lime Soda, was introduced two weeks before the stock market crash in 1929. These are just a few of the many sodas that survive in one form or another on today's market.

  Prior to the Great Depression, more than 8,000 bottling plants existed in the United States, many producing local brands that have not survived. For those that still exist, the original formulae have changed over time due to cost constraints or regulatory changes. For example, safrol, once a key ingredient in root beer, is no longer permitted. Today, root beer is essentially a combination of wintergreen or birch oil and anise oil.

  Soft drink consumption has been steadily increasing since the mid-1980s. In 1996, the average American drank more than 18 oz. daily. Colas head the pack, followed by the lemon-lime category. Regular (sugared) soft drinks far outweigh diet drinks in volume consumed. Only one-quarter of soft-drink volume was consumed at the "soda fountain," the place where the flavored-soda saga started in the States.