Water beverages are flooding the market in a tsunami of new launches, and most are overflowing with better-for-you ingredients, such as vitamins and minerals, botanicals and nutraceuticals, plant proteins, and fibers. Often, these waters need to include natural flavorants and sweeteners, as well as flavor maskers for those unwanted notes from certain vitamins, botanicals, and minerals.

The first and most obvious reason consumers drink water is to hydrate. The Oxford dictionary defines the word “hydration” as the process of causing something to absorb water. “The intention of hydration is to rehydrate the body, i.e., to replace water and solutes lost through sweat and excretion,” clarifies Kantha Shelke, PhD, a food and beverage scientist and principal of the food science and research firm Corvus Blue, LLC.

Energy is also an important component of many water beverages. “During hard activity or exercise, one needs replenishment by the most rapidly absorbed and metabolized carbs,” adds Shelke. “Glucose, sucrose, and fructose are rapidly absorbed and metabolized into energy and are therefore ideal for sports waters, with their contributions of fast calories besides taste, flavor enhancement, and mouthfeel.”

She continues, “Rehydration — the correct technical term — happens by activating the sodium-glucose pumps lining the intestine. The right concentration of salt and glucose can activate and open these sodium-glucose pumps, which in turn allow water — along with the sodium and glucose — to pass into the rest of the body to enter the various cells and hydrate them.”

This ability of the solution to move in and out of a cell (called tonicity) matters, adds Shelke. “Isotonic solutions maintain the current balance; hypotonic solutions move the water into the cell; and hypertonic solutions move the water out of the cell,” she explains.

While there is a lot of research into how to best optimize water absorption in the human body, a critical aspect of true rehydration involves the replenishment of electrolytes.

Electrolytes are electrically charged minerals that are dissolved in bodily fluids. They include sodium, potassium, calcium, magnesium, chloride, and phosphate. The loss of electrolytes through sweat makes them target ingredients for inclusion in sports products aimed at rehydrating the body.

There is no shortage in the market of products aimed at hydration. Some of these products can be found in powdered form, such as Hydralyte, LLC’s ready-to-mix flavored electrolyte powders in a stick-pack. The product contains sodium and potassium, the electrolytes most readily lost in sweat. A small amount of glucose is added as well.

Totally Absorbed

The inclusion of glucose in such products as electrolyte powders and mixes is intended to aid in absorption of the minerals during digestion. However, consumers watching their sugar intake or adhering to a keto or paleo diet may want to opt for a product without glucose. The value of electrolytes in a convenient powder format is that they’re easy to toss into a backpack or gym bag or even keep in the car.

The mixes can easily be added to a bottle of water. Some manufacturers have gone so far as to pack the mixes into the caps of bottled water, allowing their release with a quick twist. While developing ready-to-mix beverage products, it is essential that the product disperse rapidly and go into solution easily. In beverage development, this is referred to as “wettability.”

Combining the functionality of adaptogenic herbs and nootropics with sustainability, enhanced waters target mood, immunity, and a better environment. PHOTO COURTESY OF: CRUNCHY HYDRATION, LLC/COURTNEY TIMMS PHOTOGRAPHY (WWW.CRUNCHYHYDRATION.COM)

Electrolytes are naturally soluble in water, which makes the solubility aspect of product development easier. However, if other less soluble ingredients, such as fat-soluble vitamins or botanical extracts are added, these often require the use of a wetting agent such as lecithin to ensure proper mixing and consumer satisfaction with the product.

Another hurdle in developing an electrolyte-containing water-based product, whether liquid or powder, is flavor. There are several ways developers can address the issue. The first is by understanding the inherent taste of electrolyte sources. Sodium chloride (table salt) will, of course, impart a salty flavor. Potassium chloride will be salty as well, but if used at high levels, it also can impart a slight bitterness not found with sodium chloride.

Citrate forms of electrolytes, such as sodium citrate and potassium citrate, will impart less of a salty taste but will contribute a sour note to the product. Phosphates are known to lend a combination of tastes, including saltiness and bitterness. Where possible, developers should look to a variety of electrolyte sources to minimize off flavors.

At the Source

In maintaining such delicate balances between functional ingredients, flavors, and hydration capacity in a water beverage, a key consideration is the source of the ingredients. Rather than reinvent the water wheel in sourcing specialty ingredients for their latest line of flavored, hydrating kombucha beverages, Kombucha Culture, LLC’s M kombucha and BETTER TMRW, LLC’s Buoy Hydration teamed up to create a hydration drink that sources minerals from low-sodium sea minerals. Other active components include vitamins, CBD (cannabidiol), and botanical extracts.

Sweeteners in the water beverage category not only need to be more subtle than those for other sweetened beverages, they typically need to be natural as well. The current frontrunners in this arena are stevia and monkfruit. These natural, high-intensity sweeteners work well in beverage applications. They are often paired with each other to create a sweetness profile that is similar to sugar. There are many stevia and monkfruit options on the market and new stevia varieties, such as rebaudioside-M, are now widely available.

Other natural sweeteners include erythritol and allulose. These are not high-intensity sweeteners, which can be advantageous to developers, as their higher usage rates will impart added body to the product where that might be desirable. Allulose, the most recent entrant in the sweetener toolbox, is a natural sugar that behaves like sucrose or fructose (its chemical stereoisomer) in formulation but only imparts about one-tenth of the calories.

Also, unlike many substitutes for sucrose and fructose, allulose has a clean flavor that actually falls between the two, so it needs no maskers or enhancers. While it is on record as having only around 70% as much sweetness as sucrose, its higher hygroscopicity plus its ability to enhance fruit flavors make it a 1:1 drop-in for sucrose.

Since allulose’s GRAS status was set to a 30g/day standard — a restriction that currently is under review— the use of allulose in soft drinks and other novelty beverages can be restricted. However, for water beverages needing only a hint of sweetness, the neutral sweetness of allulose, coupled with its lack of aftertaste, makes it an ingredient of distinct advantage.

Erythritol, although it’s a polyol (sugar alcohol), does not cause gastric distress as some other polyols have been reported to do. However, it does have a slight cooling effect typical of polyols. This can be a plus in water-based beverages meant to be enjoyed ice cold. Developers should work closely with a reputable supplier to find the best natural sweetener sources and combinations for specific projects.

Water, Plus

As consumers demand more from their beverages, function must move beyond electrolytes and natural sweeteners. Natural extracts and juices are expanding their incorporation into functional waters. Sparkling CBD water maker Weller, Inc. recently debuted its first flavored non-CBD water product, which contains elderberry juice as an aid to boosting immunity.

As botanical ingredients become more popular in this category, product developers will need to research and explore which forms of a given botanical will work best. In the case of elderberry, the decision can be to use juice as a whole ingredient, or extracts that concentrate specific compounds within the juice. The use of an extract lowers the usage rate and any attributes that could be imparted from the crude extract or raw juice. The use of the extract might or might not be advantageous depending on the raw material from which it is derived and the design of the end product.

Flavor, of course, represents the greatest consideration. In Weller’s CBD-enhanced waters, the CBD needs to be masked as cannabinoid extracts typically impart strong or bitter notes. Combining the CBD with the right fruit concentrate or sweetener can thus solve two issues at once.

One interesting take on functional water is Fat Leaf Water’s, LLC cactus water product line. Among a myriad of vitamins and minerals, the product also contains taurine, an amino acid that has antioxidant properties. Amino acids are inherently bitter, and at increased usage levels will impart that bitter flavor into the product. Each of the line’s three flavors — Mojave Citrus, Key Lime Mirage, and Rimrock Red — is sweetened with fruit juice concentrates and stevia.

LivTru Nutrition, LLC’s Refresh and Focus Super Antioxidant Curcumin Water product line provides insight into how the functional water space is evolving. Curcumin, a phenolic compound extracted from turmeric, has demonstrated in many studies (and in a long history of traditional medicines) myriad health benefits, including antioxidant and anti-inflammatory properties. Through patented technology, LivTru developed a proprietary curcumin complex that is one of the most highly bioavailable forms of the compound on the market. The products also include theanine and kucha tea extract (a Chinese herbal derivative purported to have anti-inflammatory capacity).

A somewhat “counterintuitive” functional ingredient making its way into water beverages is plant sterols. Way2B, LLC’s Way Better Water has found a method of incorporating these usually insoluble compounds into their water product.

Such innovation is exciting and possibilities for what can be included in functional water products are ever-expanding due to the use of several technologies that make healthy, beneficial ingredients compatible with water.

Let's Get Small

When thinking about innovation in the functional water space, brand owners and developers can avail themselves of emerging technologies to make otherwise challenging ingredients work in formulation. Extant technologies have been refined and popularized through the emergence of CBD beverages. While drinks are convenient delivery systems for CBD consumers, the compound and others from hemp are not inherently soluble in water, nor do they have pleasant flavors. The CBD industry solved this dilemma by scaling and applying nanotechnology.

Nanosized particles can give compounds that are chemically insoluble in water sufficient surface area to disperse in water. Flocculation and coalescence — phenomena that lead to the breakdown of emulsions — are, in theory, slow to non-existent in these products because the particles are so small and surrounded by so much water that they don’t easily find each other. The particles are so small, in fact, that water products appear clear despite the presence of compounds that are chemically insoluble (such as cannabinoids and terpenes).

Today’s sparkling water beverages are providing such bioactive compounds as adaptogens, terpenes, and flavonoids — and, in some cases, a little kick from alcohol. PHOTO courtesy of: JIVATI INC. (WWW.JIVATI.CO)

Such nano sized particles also are more easily absorbed during digestion. This gives them increased bioavailability, and in the case of some compounds, decreases time to effectiveness.

Another useful technology is extraction, removing only the water-soluble components of the natural sources. This is only effective, however, if those water-soluble compounds are the ones that have been studied and found to have the bioactive function being promoted.

A third method of increasing solubility is to chemically alter the compound. This might include esterification, or binding to a positively or negatively charged chemical.

Finally, one of the most popular ways to increase solubility of insoluble compounds is that of encapsulation. This means encasing the compounds — on a microscopic level — within an entity that is more water-soluble, such as lecithin.

Microencapsulation is another method of getting less-soluble and even non-soluble active ingredients into a water-based formulation. A number of microencapsulation options now exist, but alpha-cyclodextrins have the added advantage of also functioning as prebiotic fibers. Cyclodextrins are bowl-shaped oligosaccharides with clear solubility. They’re made up of a ring of glycoside-bonded glucose molecules and can be produced from starch by enzymatic processes, making them suitable for clean-label applications.

For bioactive waters, dosage is a critical aspect developers must ensure. Loss of a functional ingredient can happen in several ways: physical loss of product or raw material during processing, degradation of the functional ingredient during processing (if heat processed), or chemical changes to the ingredient over time. Chemical changes over time could include binding to another chemical compound in the matrix, degradation, and interacting with the container.

Developers and brand owners would do best to initiate robust shelf life studies in order to confirm the presence and level of the functional ingredient throughout the lifecycle of the product. This will ensure the delivery of high-quality products to consumers every time. A good starting point for stability can be established through teaming with the ingredient supplier. However, practical application of any shelf life data should be carefully executed, as small changes in product matrices can have profound impacts on the chemical behavior of natural compounds.

The functional water space is exciting, with tremendous potential for growth and innovation. The opportunities and challenges will abound for brands and developers entering this space. It will be exciting to see which brands rise to the top and what innovative ingredients will be explored next in this category.