Formulating All-Natural Beverages

By Cindy Hazen, Contributing Editor

Its easy enough to find a definition for the word natural" in the dictionary. Merriam-Webster gives these two: being in accordance with or determined by nature, or having or being a classification based on features existing in nature.

It sounds simple enough, until you start talking about food product design. The Code of Federal Regulations (CFR) does not define natural. Without a standard reference, manufacturers are left to make the call for labels of nonmeat foods and beverages. To add to the conundrum, opinions within the industry vary because of the need to balance cost and meet ever-changing consumer expectations.

Flavor first

Flavors are the one category of ingredients for which FDA offers specific guidance regarding natural" (21 CFR 101.22).

Fortunately, there arent many limitations to creating natural flavors. According to Steve Wolf, director of flavor applications, Robertet Flavors, Inc, Piscataway, NJ: For the most part, anything that can be made without natural components can be made with natural components. The chemistry isnt that different. In other areas of the food industry thats not always the case."

 Norma Schwarz, R&D lab manager, Flavor Dynamics, Inc., South Plainfield, NJ, says there is a challenge, however, in creating natural, organic-compliant flavors. Many natural ingredients dont even fall into the category of organic-compliant because of the way they are processed, so you have to create the flavor with even more restrictions," she says.

Cost is another issue. Ingredient costs can run 10 to 20 times more for naturals as opposed to artificial ingredients, and this can make creating the final flavor very challenging," says Schwarz. Also, certain ingredients that are available artificially, that can create better-tasting flavors, are not always available naturally."

Flavors are process-specific. In carbonated beverages, flavor use levels tend to be a lot lower than in dairy or noncarbonated beverages," says Schwarz. Since many carbonated beverages are packed in clear plastic bottles, the challenge is creating a flavor that does not ring at the top of the bottle or create any sediment that will fall out or haze in the final product."

 In dairy products, flavors are used at higher levels because of the masking effect of gum systems and the fat content in the milk. When developing flavors for dairy beverages, you have to be careful not to add ingredients that can create off notes in the milk, especially when the final product is heated," Schwarz says. 

In noncarbonated beverages, natural flavors usually contain acids and fruit juices, which cause the use level to increase," Schwarz continues. Flavor issues arise when these products are heated. When hot-packed or aseptically packed, certain volatiles can blow off" and cause flavor loss in the final product. At this point, the flavor needs to be enhanced to compensate for this loss. These differences are challenges that flavor chemists face every day."

Perception is partly responsible for the flavor requirements of different beverages. In most carbonated beverages, the carbon dioxide in and of itself changes the way the flavor is perceived in your mouth," says Wolf. Part of it is the perception, and part of it is that in most carbonated beverages there isnt much going on there. Its just sweetened water and the flavor. Theres nothing to hide it. Carbonated beverages are usually using only citric acid or phosphoric acid, and just changing between the acids will change the perception of the same flavor."

A juice beverage has multiple contributions to flavor. Other things that are perceived in the finished beverage are coming from the sugar system, the acidulant system and things like that," Wolf says. The choice of sweetener will also impact flavor outcome. The sweetness of Reb A is distinctly different than sugar sweetness.

Texture tricks

Harold Nicoll, marketing manager, TIC Gums, Belcamp, MD, reminds us that replacing the texture that dissolved sugar provides can be tricky. High-intensity sweeteners like stevia (up to 400 times sweeter than sucrose) can replace the sweetness but not the mouthfeel that accompanies dissolved sugar or corn syrup. Without the addition of texture modifiers, the drinks will seem thin and will lack body," he says. The best gums for adding body are certain spray-dried synergistic blends of acacia gums that have enhanced emulsifying properties or texture systems that contain guar or other ingredients, still containing reduced levels of guar, that are cold-water soluble and have comparable viscosity to 100% guar gum."

Another use for gums is preventing fallout in sparkling products, such as teas or fruit beverages. Sparkling can interact with some colorants and juices to create fallout after processing," says Steve Corson, research chef, Northwest Naturals, Bothell, WA. Color may need to be adjusted over time, and gums may need to be added."

Nicoll suggests low concentrations of konjac and xanthan gums (0.03%) provide a synergistic combination that will provide suspension characteristics.

Coloring naturally

Colors usually dont interact with flavors, but they play a role in delivery. Part of tasting is the color of the product," says Wolf. When the color isnt what people expect, it can be off-putting. This may be one reason why clear colas have been less successful.

Think cola. Think caramel. But it is essential to know which of the four classes of caramel color to use when formulating natural beverages. All are labeled caramel color, but Class I is the most natural," says Campbell Barnum, vice president, D.D. Williamson, Global Support Center, Louisville, KY. Beverage designers in the United States who wish to formulate 'natural' tend to select Class I caramel because it is compliant to a product display panel (front-of-the-package) claim for made with naturally derived ingredients," says Barnum. Class III and IV caramels are produced with ammonia.

Conventional Class I caramel colors are not stable below pH 3.5. D.D. Williamson has developed a Class I caramel that is stable below pH 2.5 for soft drink concentrates. It has a negative colloidal charge and will interact with ingredients with a positive charge to yield haze in the final product," Barnum says.

When choosing natural colors, formulators should look for color additives that are exempt from certification because these are considered natural. The listing of exempt colors and their labeling requirements is found in 21 CFR Pt. 73(a). Caramel color, annatto extract, fruit juice and beta-carotene are just a few of the colors listed.

Natural colors are often seen as not being as stable as synthetic colors," says Byron D. Madkins, senior director product development and applications, colors, Chr. Hansen, Inc., Milwaukee. But thats changing. New sources are being identified that show increased stability and additional shade options. Technologies, such as emulsification and microencapsulation, imbue natural colors with more stability for given applications.

Interactive ingredients, processing conditions and shelf-life requirements are challenges to ensuring the shade and intensity are maintained. For example, ascorbic acid can interact with many anthocyanins and cause them to brown or fade. These include products like purple carrot, elderberry and purple sweet potato; therefore, it is critical that the level of ascorbic is low enough so there is not a negative impact on the color," Madkins says. On the other hand, many of the beta-carotene emulsion colors, which provide shades from yellow to orange, are stabilized by the presence of higher levels of ascorbic acid.  Further, if ascorbic acid is not present, or if the level is too low, the color will not be as stable."

Fortified beverages provide some of the greatest challenges, as they contain vitamins and minerals that can interact with the color and cause it to change or degrade," Madkins says. Calcium can interact with natural colors, such as anthocyanins, and cause many of them to fade.

Various types of flavors, depending on their chemical characteristics or classification (e.g., alcohol-containing flavors), can have a negative impact on color, as well. Microbiological organisms (bacteria, mold and yeast) can interact with colors and cause them to degrade," Madkins says. Metals and/or ions can chemically interact with natural and synthetic colorants and cause them to fade."

Dont overlook potential interactions from tap water. The quality of water is very key," says Madkins. Typical city water may contain chlorine, fluorides, sulfates and minerals, such as iron or copper. It is of utmost importance that the water used is purified in some manner, typically some form of filtration. The level present as compared to the level of the color in the system is also critical. Ingredients present at ppb levels are less likely to have an impact on the color used. But, if the levels are closer to ppm or higher, which are actually typical color usage dosages, the possibility of interaction is increased."

Managing oxidation is a crucial factor for the stability of natural colors.  Simple steps, such as optimizing processing times and temperatures, adding color to the batch tank last, adding natural antioxidants, limiting headspace, and optimizing packaging sizes and surfaces to limit light exposure, can improve stability surprisingly well," says Tracy Mattingly, director, Natracol business development, Roha USA LLC., St. Louis.  Something as simple as adding UV-protective coating to packaging can often make a difference between success and failure. As a last resort, sleeves or shrink labels can be used."

Likewise, any ingredient known to have oxidizing or reducing properties can interact with colors and cause them to degrade.

Roha has been replacing synthetic tocopherol and ascorbyl palmitate with natural alternatives, such as fruit, spice or tea extracts, to prevent browning, fading and oxidation of colors. These natural alternatives can provide a 20% boost in color retention without adding anything negative to the label," says Mattingly.

For most beverages, it is important for natural colors to be light- and heatstable, and sustainable in low-pH systems. Mono- and diacylated anthocyanins can often provide an appropriate red hue for such products," Mattingly says. Additional points of differentiation can be created by using clouding agents to shift shades from red to pink.  Sweet-potato and red-cabbage colors can provide a more fuchsia shade."   

 For mid- to neutral-pH beverages, such as soy and dairy drinks, she recommends carotenes as better natural-color solutions, rather than anthocyanins.

Acylated anthocyanin-based colors also work well in carbonated and still, acidified beverages. Precautions, however, should be taken to protect these colors from browning," Mattingly cautions. Carotene colors, which fare well in most acidified still beverages, sometimes have difficulty performing in the pH extremes required of carbonated sodas and their corresponding syrups. Signs that the colors emulsifier is not working include ringing, sedimentation and excessive foaming."

Carol Locey, director, product management colors, Kalsec, Kalamazoo, MI, points out: Color emulsions are required for oil-soluble pigments, whereas water-soluble, natural color pigments can be used in their natural form. The formulator is challenged to ensure the formulation and emulsions are compatible to prevent pigment instability and ringing out.  Therefore, it is important for the manufacturer to create a relationship with their color supplier to ensure the best solution."

Madkins explains the point of addition for the color is critical. The ringing effect that is seen in beverages where emulsions are usedbeta-carotene, for exampleis due to the emulsion breaking and releasing the oil-based colorant, which rises to the top of the beverage container and forms a distinct ring," he says. This may be due to processing conditions, exposing the beverage to harsh storage conditions, improper packaging, oxygen in the bottle headspace, or possibly any combination thereof. However, it is typically possible to develop and formulate color systems that are robust enough to handle even some of the most challenging conditions in the beverage application."

To avoid unpleasant hues, its important that the supplier understands all of the processing conditions. Anthocyanins are very functional in beverages at a low pH; however, at a higher pH, such as dairy-based beverages, the anythocyanin pigments are less stable and may convert to an undesirable blue or grey color," says Locey. Changes in ingredient composition, processing storage and packaging conditions can all impact a formulas stability."

Color selection should meet customer expectations. For dairy-based beverages like smoothies more subdued colors are used because people expect smoothies to be very natural in appearance," says Emina Goodman, technical support manager, beverage and dairy group, Sensient Food Colors, St. Louis. The visual appearance of fresh-crushed fruits is not as vibrant. Consumers are familiar with this by watching their smoothies being made, so the expectation of a natural appearance exists. Superfruit hues are popular color targets.  We are able to replicate the look of crushed fruits like pomegranate, açaí and blueberry to meet this need. Beverages targeted toward kids are always bright."

Yet nature cant always duplicate mans creations. Finding a natural blue color that can replicate the rich shade of certified colors is difficult. Since blue is a primary color that is also used to develop green and purple shades, this gap affects the development of vibrant green and purple shades," says Goodman. We have made significant advancements in the development of a natural blue color, which was previewed at the 2011 IFT Show.  We are testing this natural blue shade with selected customers."

Purple is also difficult to achieve at lower pH. Stabilized grape concentrates can provide some variation," says Mattingly.

Emulsification issues

If a beverage requires oil-soluble ingredients, it will require some sort of emulsifier. Imagine trying to make an orange-flavored carbonated soft drink without using an emulsifier," says Dinah Diaz, market development manager, National Starch Food Innovation, part of Corn Products International, Bridgewater, NJ. After a few hours the oil and water would separate and the beverage would be unappealing. Another important use of emulsifiers is that they are necessary for the delivery of oil-soluble actives and nutrients, such as omega-3, beta-carotene or vitamin D. Any time a formulator wants to deliver an oil-soluble ingredient, color or active, they need to use emulsifiers." 

The problem is, many emulsifiers are not natural. Gum arabic is commonly used, but according to Diaz, other emulsifiers, such as OSA-modified starches provide many benefits over gum arabic, such as low cost-in-use. However, they are not natural and are labeled as modified food starch."

A natural alternative is an emulsifier based on saponin that is extracted from the quillaja tree. It can increase versus gum arabic, says Diaz, because it carries three to four times the oil load of traditional systems, promoting greater efficiency in production, warehousing and shipping. It is sourced from the quillaja plant and is processed using completely natural methods. Quillaja is reliably sourced. The quillaja plant is sustainably harvestedno trees are cut downin plantations in Chile." The quillaja-based emulsifier also eliminates the need for weighting agents, which reduces ingredient costs, she notes.

Basically dairy

Dairys healthy halo makes it an ideal base or addition to all-natural beverages. For high- acid/low-pH products with protein fortification, Luis Hernandez, senior application scientist, Fonterra USA, Inc., Rosemont, IL, recommends using a functional whey- protein isolate (WPI). Current technologies allow creation of clear, stable beverages with minimal to no detectable changes in flavor," he says. We have successfully developed prototypes of near waters, recovery beverages, green tea, carbonated soft drinks and juice drinks using specialized WPIs." The recommended pH is below 3.6.

Optimizing the heating and cooling of clear, high-acid beverages is key to achieving the best possible product. Whey proteins are heat-sensitive, meaning they tend to denature and fall out of solution if they are exposed to heat," Hernandez says. This denaturation starts at around 140° F; therefore, the combination of time and temperature selected to pasteurize a product is key, along with the rate of cooling. As a rule of thumb, the less time the product is exposed to heat, the better. New developments in whey-protein ingredients have resulted in functionality that can withstand regular HTST or UHT processing conditions."

Opaque, or milky, high-acid, low-pH beverage systems, such as smoothies, are generally at a pH of 3.8 to 4.2. Milk powders and milk-protein concentrates or isolates are potential ingredients if a suitable stabilizer system is used to keep the casein from precipitating. Whey proteins are also an option, with their pH stability providing ease of use and more stability than casein," Hernandez says.

Low-acid, neutral-pH beverages have a pH close to that of fresh milk, which is 6.7. To ensure shelf stability and prevent issues, such as change in viscosity, sedimentation or phase separation, consider the amount and type of protein, pH both during and after heat treatment, the amount and type of other ingredients present, such as vitamins and minerals, and the type of processing and heat treatment.

When using any dairy ingredients, consider the potential for interaction between protein and other ingredients in the beverage formulation, which can result in instability of the beverage. This is formulation-dependant and requires experimentation to find a solution. In some cases, an adjustment in pH or change in beverage viscosity may prevent sedimentation," Hernandez says.

Another problem that can plague some beverage systems is heat-exchanger fouling, an accumulation of materials on the surface of the heat exchanger. This causes reduced efficiency of heat transfer and limits the batch sizes," says Bonney Oommen, business development manager, Glanbia Nutritionals, Monroe, WI. Once fouling occurs, one has to stop processing and clean the system to regain the efficiency. This is a challenge in products with sugars and/or proteins." His company has developed ingredients to limit heat-exchanger fouling.

Healthful additions

Heat may also be a detriment to probiotic ingredients that are often added to dairy or juice beverages for their digestive-health benefit. You must keep in mind that these are live microorganisms that are quite sensitive to harsh temperature and pH conditions," says Eric Reamer, associate industry manager, beverage and confectionery, Danisco USA, Inc., New Century, KS.

 Low temperatures are best (refrigerated storage) and pH typically must be kept at around 4.0 or higher. Shelf life can be an issue here, as well, but under proper conditions 60 to 80 days is certainly feasible," says Reamer.

He sees heart-health and bone-health beverages becoming important areas for innovation and product differentiation using such active ingredients as omega-3s, phytosterols, beta glucans, calcium and vitamin K2.

In stealth-health formulations, fruit and vegetable blends are the base or additions. Purée and particulates may be an issue for some bottling lines," Corson cautions. Temperature and time must be monitored to avoid a burned note in the particulate.

Consumers are becoming more educated and aware of the foods they are eating. They are reading labels more closely and are looking for better for you options," Corson says. Specifically, for beverages, many consumers are looking for natural energy and high flavor impact."

The challenges for the food industry are many, but processing and stability issues aside, the true task is determining and meeting the consumers definition of natural.

Without a federal definition for all-natural, individual companies and retailers are leading the market and self-defining these terms," says Locey. For example, in an all-natural orange juice, a beverage manufacturer may be comfortable coloring their juice with annatto, while other manufacturers may choose a natural orange color derived from oranges."

Wolf sums it up this way: I see the industry coming back to where it started from. The interesting thing is it works fine as long as people are coming from an area where they understand what limitations there are with natural."

Cindy Hazen, a 20-year veteran of the food industry, is a freelance writer based in Memphis, TN. She can be reached at [email protected].