How should we provide the minerals consumers so desperately need and formulate the new 'anytime' sports and energy beverages? Consumers want delicious beverages, which they define as refreshing and clean, with no artificial taste or unfamiliar sensory experience. They want a beverage that is 'good,' which seems to mean safe and natural, and easily understood as having a health benefit. They expect hydration, performance improvement and the feeling that the beverage is adding to their quality of lifestyle. Fruit and vegetable juices, proteins, teas, water, and herbal elixirs are understood by consumers to have intrinsic healthfulness. They easily understand label claims such as "as much calcium as an 8oz serving of milk."
In order to be refreshing, sports and energy beverages contain mostly water, with other ingredients such as juice or protein being used on the light side. For the minerals, considerations are mineral load (content of the 'active ingredient'), cost, ease of use of the mineral in the manufacturing setting, taste, how it affects the flavour of other ingredients in the formulation by virtue of taste or buffering capacity, and whether the ingredient is eco-friendly.
Classic sports drinks replace electrolytes and water lost through perspiration, and usually also contain rapidly metabolised carbohydrates. Classic energy drinks commonly add B-vitamins and caffeine for a rapid pick-me-up. However, if we consider that consumers want to feel vital and energetic every minute of the day, then we have a good case for adding minerals, primarily calcium, magnesium, zinc and potassium.
Nothing is better for feeling great, including having sharp mental acuity, than a good night's sleep — lack of sleep is worse for mental functioning than lead poisoning. Calcium and magnesium promote good sleep, and also optimise energy metabolism and improve muscle contraction and nerve activity for sports performance. Also, we cannot ignore the relationship between cardiovascular death and a lack of magnesium. Zinc can also play a role in energy mobilization within the body, promote muscle endurance in sports and shore up the immune-system endurance. A mere 2mg of zinc daily can keep blood-sugar levels stable, preventing headaches, moodiness, fatigue and increased hunger. Potassium, meanwhile, already has an FDA health claim: diets containing foods that are good potassium sources and are low in sodium may reduce risk of high blood pressure and stroke.
With regards to mineral load or amount of actives in the mineral, there are forms with high actives such as magnesium oxide and calcium carbonate. However, the high-active forms usually are not soluble enough for beverage applications, and relatively soluble forms such as calcium malate and calcium fumarate are not soluble enough in concentrates such as carbonated soft-drink bases or yoghurt-fruit preparations used in drinkable yogurt. Even if a salt is soluble the taste may not be good at usage levels above 10 per cent RDI.
To the rescue are the lactates, gluconates, lactate gluconate, and mixtures with lactates (such as the newly launched PURACAL QSynergy, calcium lactate citrate). These mineral forms deliver on natural, bioabsorbable and taste, and are soluble over a wide pH range. In the discussion that follows I will therefore primarily focus on the lactate and gluconate salts.
Getting down to details
When formulating the anytime beverages, one should either replace the minerals lost in physical activity or add 10-30 per cent RDI. The sports thirst quenchers are isotonic with 314mOsmol/kg of soluble solids and this could be optimized by adding 78 — 195mg/l potassium (helps balance water in the cells, improves heart-muscle action, promotes better transmission of nerve impulses, regulates blood-sugar level and replenishes salt), magnesium at 4-34mg/l (improves muscle contraction, energy synthesis and salt replenishment), and calcium at 13-67mg/l (increases bone mineral content and improves muscle performance). And consider adding zinc for muscle endurance.
When deciding if the lactate form or the gluconate form is best, consider the balance of sweet and tart. The lactates tend to accentuate tart, while the gluconates and citrates accentuate sweet. And note that lactic acid and lactate are a positive for sports drinks. Oral lactate may postpone fatigue by neutralising (buffering) the acids naturally produced in the body, and can also serve as a noninsulin-dependent energy source. Lactic acid, in contrast to citric acid or phosphoric acid, is a mild-tasting acid that lasts long enough during the tasting experience to create excellent flavour enhancement as well as to make intense sweeteners such as sucralose and aspartame taste more like sugar. With so many sports and energy beverages lowering calories and sugars by use of intense sweeteners, the use of natural lactic acid should be explored.
The soluble minerals used at levels to replace loss from sporting activity would not likely be enough to interact with anything, or be difficult to dissolve, or be detected by taste or smell. Because our new 'anytime' sports and energy beverages will be at the 10-30 per cent RDI, interactions with other ingredients need to be considered.
For example, a mineral water with low-carbonate content can be fortified with calcium lactate, but a high-carbonate mineral water can form calcium carbonate with calcium lactate. The problem is solved if calcium lactate gluconate is used in place of calcium lactate. Some magnesium sources become more soluble at lower pH values. For instance, magnesium carbonate becomes more soluble at a lower pH; however, carbonate reacts with H+ ions resulting in CO2 gas formation, which in turn increases pH and flattens flavour. The formed carbon dioxide gas must be excluded from the beverage under vacuum. Teas of high polyphenol content can interact with calcium lactate, and again calcium lactate gluconate is a stable choice, or source teas with lower polyphenol content and calcium lactate can be used.
Additional help in stability is achieved by using lactic acid in place of citric acid or in place of phosphoric acid because soluble calcium can interact with these acids to form low-soluble calcium citrate or calcium phosphate.
And a last note: a blend of lactate and gluconate varieties might be optimum when adding multiple minerals. All minerals in the lactate form may give too much acid taste. All minerals in the gluconate form may be slightly too sweet. When adding 30 per cent RDI each of magnesium, zinc and calcium to a drinkable yoghurt, we noted blends of calcium lactate gluconate, magnesium gluconate and zinc lactate or calcium lactate gluconate, magnesium lactate and zinc gluconate tasted particularly good, and were rapidly soluble for the syrup concentrate phase added to the yoghurt mass of the drinkable yoghurt.
You have an opportunity, and I would argue an obligation, to broaden the appeal and effectiveness of sports and energy beverages. Mineral enhancement is the key.
Gale C Walters is an account manager for PURAC America in Illinois. She has 27 years experience in the food industry, and is co-author of the book, Scientists Must Speak: Bringing Presentations to Life. Respond:[email protected]