High-Energy Beverages

  The kick-start category started during the 1980s in Southeast Asia where these products were used by overland truckers. But these high-energy beverages soon found their way across the globe. "(This category) was brought to Europe, where it took on a different function," says Greg Horn, director, beverage applications, Wild Flavors, Cincinnati. "It became very popular with the young set at discotheques, where it was sold for 'raves,' the night-long or weekend-long parties. People wanted something that would keep them up all night. Then use branched off with students who wanted something that tasted better than coffee. Athletes picked up on the products for quick energy."

  The category pushes carbohydrate combinations - generally, glucose, fructose and maltodextrins. The glucose and glucose-yielding maltodextrins are fuel for the body's energy reactions. B vitamins are added, as they are involved in mediating metabolic reactions yielding energy. Vitamin C is the antioxidant of choice, although vitamins A and E also are popular for this purpose. Botanicals are often present as well. Of the commercially available herbal extracts, guarana contains the highest caffeine levels and is frequently added to provide a booster effect. Additional caffeine can be added up to the U.S. legal limit of 200 ppm. Another popular additive is ginseng extract, of which three types exist. The Chinese have prized ginseng thousands of years for its purported "invigorating" effects.

  Workout beverages supply salts and carbohydrates, and usually also contain vitamins, minerals and amino acids (for rebuilding muscle). Additives for muscle functioning, such as creatine monohydrate, might be added, as well as additional antioxidants. Other possible additives range from glutamine peptide to coenzyme Q10.

  The isotonics, by far, dominate the energy-drink category. The workhorse of the sweat set, this group is designed to replace salt, carbohydrates and water on an efficient, readily assimilable basis during exercise. Changes are likely to come in this category as well, especially since research on the link between nutrition, dieting and exercise continues to reveal new information useful for beverage design.

  The chain of reactions - known as glycolysis, the tricarboxylic acid cycle and respiration - provides ATP, the energy storage compound of the body, through the reactions yielding ultimately ATP, carbon dioxide and water. ATP reacts with muscle creatine to form creatine phosphate. The creatine phosphate provides the energy required for muscle contraction. Normally, creatine is abundant in muscle. Since it's only obtained from muscle meats, people on vegetarian diets would benefit from creatine monohydrate additions. Creatine monophosphate is used in some powdered diet supplements.

  Salts in isotonic beverages make water more available to the tissues. An isotonic beverage provides a level of salts at equal osmotic levels with blood plasma to prevent loss of salts through sweating. The sugars and other carbohydrates function to allow maximum absorption of water by the body to maintain optimum energy utilization. The higher sugar levels of a typical soft drink (10% to 13%) absorb more water, thereby slowing its transfer. Water intake during extended exercise is just as critical, if not more so, than any other functional component in an energy beverage system.

  In formulating a sports beverage, a blend of carbohydrates such as maltodextrins, corn syrup solids, high fructose corn syrup, crystalline fructose or glucose is used, according to Tonya Armstrong, applications scientist, Grain Processing Corporation, Muscatine, IA. Blends yield a somewhat extended supply of glucose due to differing metabolic rates of conversion to glucose.

  Glucose, in the form of crystalline glucose, or high glucose corn syrup, is the source of quick-energy carbohydrates in energy beverages. Maltodextrins are very easily digested, and yield glucose almost as fast, while providing a rich source of glucose at body osmolality. Other carbohydrates yield glucose at varying times due to metabolic activity. Fructose and high fructose corn syrup are more slowly isomerized to yield glucose. Other sugars such as maltose are made available at various rates.

  In an isotonic beverage, the optimum osmolality is 280 to 300 milliosmoles, which is the body osmolality. An osmole represents the osmotic pressure produced by 1 mole (gram molecular weight) of solute per kilogram of solvent. The use of 280 to 300 milliosmoles, equivalent to a solution of 5% glucose or 22% 18 DE (dextrose equivalent) maltodextrin, would be the highest level of carbohydrates used as the carbohydrate supply in an isotonic beverage. The advantage of using a higher DE maltodextrin is its clarity in solution, low viscosity at high concentrations, and the ability to add a relatively high amount of glucose polymers without affecting the osmolality of the beverage.

  One aspect of isotonics formulation employs the balance of sodium and potassium chlorides to maintain the physiologically required levels for the functioning of the central nervous system. For this type of beverage, the chlorides generally have to be added, as most sources of water are not very high in sodium, or potassium and chloride levels are low. Where sodium levels are high and/or present with other anions, ion exchange might be indicated.

  Calcium is primarily needed for bone replacement, and is essential for exercise and health. Its various roles in cell-transport mechanisms, enzymes and blood-clotting indicate a high daily requirement. Designers wanting to increase calcium above naturally occurring levels can use bioavailable ingredients, such as gluconate and lactate. Solubility and flavor problems might occur when certain calcium salts are added. Lactate, tricalcium phosphate and gluconate all have advantages. Lactate and gluconate have very high bioavailability as well as bland tastes. Gluconate has high solubility and masks some bitter tastes.

  Calcium is fairly high in regions having hard water. Removing inherent toxic metals, such as lead and radium, also will remove calcium. Typically, 10% to 25% of the Daily Value would be an amount to target.

  Phosphorus is the second most important mineral in nutrition. It constitutes a large percentage of bone mass as calcium phosphate is the primary mineral. But its roles in DNA and the ATP energy mechanisms make phosphorus extremely important nutritionally. Adequate intakes of phosphorus, such as from dairy products and vegetables are important, as calcium and phosphorus interfere with each other's uptake. The amount added in the product should be based on the amount that is normally consumed in a balanced diet, which often would be a large percentage of the Daily Value.

  Magnesium is an important mineral involved in release of energy for muscle contraction, as well as maintaining electrical potential in the nervous system and membranes. It also is interactive in reactions involving phosphorus and calcium. Magnesium can be added to formulations in the form of oxide or lactate. Magnesium compounds often are bitter, and appropriate flavor masking would be required. Magnesium additions in bioavailable forms may be included if diet is inadequate. The designer should take into account average statistical dietary intakes for the typical customer base. Then, a rational amount of Daily Value may be added to the product.

  Zinc, in the form of oxide, gluconate or monomethionine, is involved in carbohydrate metabolism. Zinc has increasingly recognized roles in immunity functions, and has attained celebrity status. However, too much zinc can lead to gastrointestinal problems, and also might interfere with copper functions. Only 3 to 5 mg are required per day, and multiple ingestions of this element would dictate using a percentage Daily Value approach. Using this method, 10% to 60% may be added, depending on expected daily consumption of the product, as well as other dietary sources.

  Iron is important in the oxygen-carrying role of hemoglobin, as well as in the oxygen storage compound myoglobin found in the muscles. The role is one that is performed at a very low concentration in the blood, and amounts exceeding the Daily Value aren't recommended. The compound can be added as a chelated salt, for iron is not very soluble in many beverages. The bitter off-tastes developed would need masking. Also, iron catalyzes oxidation of flavors, which is another reason to limit its addition and protect the beverage with a chelating compound such as a rice protein.

  Copper works in concert with iron in the formation of hemoglobin, and can be added as the gluconate. Copper, like iron, catalyzes oxidation of flavors.

  Micronutrient metals have gained substantial press focusing on their energy production-related properties. Chromium, in the form of polynicotinate, has been added to promote weight reduction, though its role in weight reduction during exercise hasn't been established. "Its use in a number of studies tends to indicate the opposite effect," says Forest Nielsen, Ph.D., center director, Human Nutrition Research Center, USDA, Grand Forks, ND. "Chromium is involved with insulin, but it is a mineral required in very low quantities."

  Dietary amounts of 50 to 250 µg per day of the trivalent form of chromium will probably present very little problem, Nielsen says. Chromium seems to have some effect in glucose metabolism. Less than 20 µg per day also may prove problematic, due to its necessity as a micronutrient. It's when intakes approach 2,000 to 3,000 mg per day from multiple doses that chromium could become a concern because its toxicity or metabolic function at these levels is unknown. Not enough research has been done on toxic buildup of some of the metallic minerals in the body, especially when their bioavailability has been enhanced.

  "The vanadyl form of vanadium has been used as a fat burner as well in some products," Nielsen says. "This mineral can definitely create a problem, as it will accumulate in the body, and it may be carcinogenic."

  B1 (thiamin) functions as coenzyme thiamin pyrophosphate, part of the glucose oxidation process. About 1.0 to 1.5 mg is normally required daily. Fortunately, thiamin is heat-stable in acid beverages, but concentration would have to be increased when used in a product at neutral to alkaline levels, due to its instability at higher pH.

  B2 (riboflavin) is active in oxidation at the cellular level, and is required for cell growth. Riboflavin also is heat-resistant, but not light-resistant: Inclusion in a product would require packaging that restricts light transmission. The typical daily dietary requirement is 1.0 to 1.5 mg.

  Niacin is required for glucose oxidation and respiration in tissues - 10 to 20 mg is necessary on a daily basis. It is water-soluble and stable to oxidation, light and heat. B6, consisting of pyridoxine, pyridoxamine and pyridoxal, is required for metabolism. Only 2 mg is normal for daily consumption. Pantothenic acid may supply tolerance to stress, including heavy exercise; 5 mg is an apparent daily requirement. B12 is active in carbohydrate and fat metabolism. The daily requirement is very low, at 2 µg.

  Vitamin C (ascorbic acid) is a strong antioxidant, making it a valuable addition to energy beverages. Since it's easily lost to oxygen, reducing oxygen in the beverage is a high priority. C functions in the formation of the protein, collagen, which is vital to connective tissue and skin. Whereas the Daily Value is relatively low at 60 mg per day, higher quantities can be used by the body as an antioxidant, particularly during exercise.

  "We follow the recommendations of the American Herbal Products Association," Kreienbrink says. "They have handbooks on safety and levels of use. Much of their information is derived from the British and from the German Pharmacopeia, which has set levels of herbals within reason. The American Herbal Products Association is trying to set standards. They're trying to self-regulate and police the use of these materials."

  Much of the news surrounding the use of St. John's Wort for mood elevation stems from one study incorporated into the British Pharmacopeia. This is only one study, but as money becomes available, more scientific studies will be conducted to determine active compounds in plants yielding advantages in energy beverages. There is a good chance that plant materials might yield the next great stride forward in energy use, health, nutritional and life-enhancing research data. With compendia of medical traditions, and the largely assay testing and purification methods of the British and German Pharmacopeias, there is a general lack of rigorous scientific data on the nutritional and medical properties of herbal products, according to Meskin.

  In April, FDA announced a proposed change to dietary supplement labels. The agency is seeking to prohibit the use of claims that indicate or imply that specific diseases or conditions can be be cured or alleviated with a product. Allowable claims would be general in scope, and not list specific diseases or effects on symptoms. These structure/function claims, which wouldn't require FDA approval if they meet the guidelines, might include such descriptions as: "energizer" or "rejuvenative." Proposed prohibited statements include: "protects against development of cancer," "lowers cholesterol" or "supports body's antiviral capabilities."

  Increasing attention has been focused on phytochemicals. A main focus has been on antioxidants, excellent sources for applications of botanicals in beverage systems. Antioxidants can act to extend the life of the product, as well as the consumer. By protecting flavors, compounds such as ascorbic acid can aid the designer in building in a longer shelf life. Many fruit extracts, such as acerola, contain large amounts of vitamin C. "Antioxidants act as a primary defense against free radicals, such as the hydroxyl radical formed during exercise," Meskin says. The gradual breakdown of DNA restorative functions can lead to heart disease and cancer.

  Some natural dyes possess antioxidant properties. Anthocyanins, the red-to-purple pigments found in fruits, possess these properties, as do carotenoids. While these compounds aren't as stable as many certified dyes, the added value of their functionality, their usefulness as beverage pigments, and the added flavor of any juice component used as a colorant is reason to consider this class of components in a product design. Products having high tinctorial strengths, as well as high pigment contents, include: blackberry, blueberry, black chokeberry, elderberry and red cabbage.

  Carotenoids, including B-carotene and lycopene, are well-known antioxidants. These natural pigments find utility in beverages in hybrid fruit/vegetable blends, as well as for general cloudy beverage use.

  Methods of approaching the final design of the beverage depend on the product shopping list, but some general guidelines can be given. "A good approach to the process is to taste the flavorless base, and look at the system you have to deal with," says Alan MacFadden, manager of beverage applications, McCormick Flavors, Hunt Valley, MD. "Then you look at what flavors will marry best with the base."

  Bitterness reduction can be achieved through several methods, MacFadden says. The use of high-intensity sweeteners might suppress this taste. Blends of aspartame and acesulfame-K, as well as sweet, purified compounds of the stevia plant, can be tested. Masking flavors can be used to reduce bitterness. The source of bitterness affects what masking additives can be used. Kava kava extract seems to have a numbing effect in the center of the tongue, which can aid in reducing bitterness. Masking can be accomplished in cold beverages by using thermogenic masking. The thermogenic flavors release volatile flavoring compounds at low temperatures. Some products possessing this attribute include honeydew melon and cassava melon flavors. Another method involves using flavors with an inherent bitter component. The designer could, for instance, blend a debittered grapefruit flavor in a bitter beverage base to yield a beverage with the expected bitter profile.

  Spices can mask bitterness as well, though large amounts of some can introduce their own bitterness. Cinnamon has a sweet taste, with a warming effect that might somewhat modify the bitterness of a formulation. Other warming spices, such as nutmeg, clove and allspice, have a similar effect, but must be used very sparingly. Vanilla is another sweet extract that can round out and mellow the taste of a harsh profile.

  Recovery beverages, designed to replace carbohydrates, amino acids or both after heavy exercise, benefit from combination flavors like orange/pineapple or orange/pineapple/banana. Vanilla can be worked into some of these products as well to give a creamy character. The object of flavoring is to blend flavors with a high profile to overcome the base notes. Ideally, a high initial spike of flavor followed by a rolling flavor that lingers along with sweetness and the other basic tastes is sought to yield a full experience, according to MacFadden. If flavors drop off too soon, the designer is left with an unbalanced profile of saltiness, sweetness or bitterness to overcome. Manipulation of the flavors is required to match and/or mask the background.

  Earthiness is another note found in many botanical beverages, according to MacFadden. Masking of these notes can be done with flavors such as pineapple or grape. Altering the flavors helps with the off-notes. Furaneol in pineapple or additions of hexenal lend fresh notes to the earthiness accompanying botanical extracts. Cinnamon extract also can tone down the earthiness. Altering the acidulant composition can aid the profile as well. Malic acid or tartaric acid in grape can be of use in balancing the profile. The sharp spike of tartness, followed by the lingering tartness of malic acid, maximize the effect of the flavors.

  Isotonics with significant salt levels are a challenge. Citrate buffers along with appropriate acids can add taste modification beyond the chloride character, particularly in body and tone. Using sweetness modifiers, such as glycyrrhizinates, at levels of about 10 ppm to 20 ppm, can somewhat mask the salt effect. These derivatives of licorice extract can't be used at a very high level, as the licorice flavor will begin to appear. Flavors with deep, multifaceted profiles, such as tropicals and blends, work better to mask and balance the salt.

  Powdered beverages contain a certain amount of water, depending on hygroscopicity of ingredients and humidity under manufacturing conditions. Moisture level can adversely affect ingredients such as acids and flavors. Therefore, moisture control needs to be addressed. Slowly soluble compounds or blends can be agglomerated. Carriers such as sugars can be blended with gums to speed dissolution, and reactive materials can be encapsulated with gum arabic or modified food starch to prevent interaction due to product water. The product should show no stratification, which would create an uneven blend. This separation of particles might yield a very unacceptable change from beginning to end of the run.

  Ready-to-drink beverages require more technology. Basically, the pre-mix is prepared in a mixing tank, using an order of addition that will not create solubility problems in the finished beverage. The product is then heat-processed. A typical beverage might be hot-filled, aseptically filled, cold-filled or cold-filled with a preservative.

  Oxygen removal in hot-fill beverages is often accomplished by using ascorbic acid and minimizing beverage headspace in the package. The ascorbic acid will reduce the oxygen, although off-flavors can develop from this reaction as well. Vitamin C reduction can be significant, depending on pasteurization and filling conditions. Generally, additional ascorbic acid is added to cover losses during shelf life to achieve a concentration at, or above, the level claimed at the expected sale date. Erythorbic acid, the isomer of ascorbic, tends to act as a sacrificial reductant of oxygen. Though it has no vitamin activity, it is a faster reductant and generally costs less, providing higher residuals of ascorbic acid when used in combination with ascorbic acid. Levels up to 500 ppm can be used, coupled with ascorbic acid at 250 mg/l, according to Jungk.

  One avenue of opportunity to quality improvement in energy beverages is oxygen removal prior to bottling. "This step can be performed by an in-line deaerator, which will remove much of the oxygen just prior to filling," says Gary Hammond, sales manager, Tetra Pak Inc., Chicago.

  Solubility of ingredients added to the beverage is a critical element. PSDs are somewhat easier in that regard, as they are prepared relatively soon before use. PSD requirements are fairly high solubility, rapid solubility and/or suspension of gums and particulates, along with relatively low sediment or floating residue. Shelf stability is a lesser concern, since water is at a relatively low concentration. Materials such as oxygen-sensitive vitamins can be coated to prevent loss in packaging if necessary.

  The convenience of ready-to-drink beverages is apparent, although the issue of shelf stability is more prominent. The possibility of interactions, vitamin loss, and degradation of flavors and colors, are all factors that limit the window of opportunity for these formulations. The designer's main challenge with ready-to-drink beverages is creating the most nutritionally useful product possible that also packs appeal and uniqueness.