Natural Sweeteners: Looking to a Future in Stevia

November 2, 2011
Robby Gardner

Three years since achieving FDA GRAS status, the market for stevia is maturing quickly.

It wasn’t so long ago that stevia (stevia rebaudiana) just looked like an out-of-place dietary supplement. But when Generally Recognized as Safe (GRAS) status finally came for the ingredient in 2008, the dietary supplement turned into a natural sweetening alternative for foods and beverages.

Now, stevia sits among the leading U.S. sweeteners. Sales of one stevia brand even rival those of Equal and Sweet’N Low. Consumer recognition of the green-leafed sweetener is suddenly well established. So where does stevia go from here?

Plant Breeding

As a service to both customers and the integrity of stevia, today’s specialists are improving the plant in ways that can cut cost, increase yield, and even improve taste.

According to Michael K. Quin, senior vice president of sales and marketing for Sweet Green Fields LLC (SGF; Bellingham, WA), specialized breeding “can level the playing field between stevia and other alternative sweeteners which have historically been available at lower prices.”

Most work on stevia breeding has gone towards improving yields of rebaudioside-A (Reb A), a primary sweetening constituent of stevia that is most commonly associated with positive sweetness.

Cargill (Wayzata, MN), manufacturer of Truvia tabletop stevia sweetener, claims to have increased the Reb A content of its product by over 60% from plant breeding alone in the last two years. In August, PureCircle (Oak Brook, IL) introduced a new Star 1 plant variety, boasting increased Reb A content and 33% increased yield from dry leaf compared to control plants.

While increasing Reb A remains a common investment for stevia suppliers, decreasing the plant’s inherent bitter compounds is another route for improving the stevia sweetness profile. This approach has become a cornerstone of business for GLG Life Tech Corp. (Vancouver, BC, Canada), which has already patented processes for literally removing bitter-contributing compounds from more amiable ones.

Removing bitter-tasting compounds allows for the taste of stevia to more closely resemble the sweetness of sugar, whose short tail of sweetness is a benchmark standard  for stevia extract manufacturers. Charles Tremewen, director of marketing and communications at GLG Life Tech, explains why this method may be preferred over the more conventional increasing of Reb A.

“Traditional extraction methods have been based on purifying Reb A glycosides to a very high purification level of 95 to 97% purity or higher,” says Tremewen. “Although this method reduces the negative impacts, it still does not eliminate the compounds that cause the lingering and often negative issues historically associated with most stevia extracts. Use of masking agents and creating sugar/stevia blends are ways to mask, but not eliminate, the taste problem.”

Regulatory Climate

The rise of a global stevia market will undoubtedly come through global groups assigned responsibility to advise on food standards. Most notably, 2011 stevia talk has focused on the European Union, whose member states endorsed a commission proposal in July to allow the sweetener’s use in foods. All plans to move stevia forward in European foods and beverages await a vote by the European Parliament, expected by the end of the year. Already anticipating the green light, U.S.-based PureCircle just opened a European headquarters in London.

The European Food Safety Authority (EFSA; Parma, Italy) evaluated the safety of steviol glycosides in April 2010 and found no safety issues but did note a need to cap Acceptable Daily Intake (ADI) levels at a daily 4 mg per kg body weight.

The Codex Alimentarius Commission (Rome) is another key organization, formed by the World Health Organization (WHO) and Food and Agricultural Organization (FAO) and recognized by 180 member governments. Codex now appears ready to push stevia globally. The group adopted proposed maximum levels for steviol glycosides in foods and beverages this July.

Quin of SGF outlines the implications of such a global announcement. “Food manufacturers now have guidance on safe levels of use of the sweetener in their products,” he says. “SGF is specifically affected, because these levels provide it with useful formulation limits to recommend to customers with particular applications, thus assuring everyone that the amount of the natural sweetener in a product is safe for people to use.”

David Nichols of PureCircle echoed the positivity, noting that the move should ultimately unlock a number of important markets, including India, Indonesia, Thailand, and the Philippines-countries which he says look for Codex adoptions of food ingredients to support their evaluations and approvals.

Market research group Packaged Facts spoke on similar terms in a summer press release. “Following approval in Europe, Packaged Facts expects sales of products containing stevia to skyrocket,” it predicted. “European approval is projected to trigger approval across Africa and the Middle East, and global approval is widely expected by the end of 2012.”

Growing Local

Who says stevia has to be imported from Asia and Latin America?

This year marked a great moment in stevia growth with the first-ever commercial harvest of stevia in the United States. Sweet Green Fields is responsible for this Reb A harvest in California, and Quin tells us just how important this is for a stevia ingredient:

Primarily, SGF decided to invest in a U.S. harvest to assure their customers a higher level of control of the supply chain. With this crop literally right in our backyard, every single aspect is under our watch, and it’s amazing to be able to easily tour potential buyers right through the crop they can eventually purchase. A barrier for many companies to grow in the United States is that manufacturing and agricultural costs can be much higher here, meaning the end-product would not be competitively priced. However, because of the propriety stevia plants SGF has created, we get much higher glycoside levels and Reb A biomass per acre.

Higher Testing Standards

With stevia coming on three years as a recognized U.S. food additive, it’s about time we treat it more seriously. Those employed at the International Stevia Council (ISC; Brussels) are doing just that, having launched a Proficiency Testing Program last May.

The ISC contends that the main purpose of the program is to allow interested parties to benchmark the accuracy of their own steviol glycoside testing equipment. During a four-round course, participants submit stevia samples along with their own analyses to the program’s recognized testing administrator (UK-based LGC Standards Ltd.), which then performs its own checks. Participants can then compare their results and solicit assistance from ISC-appointed technical advisors who are available to help with any unresolved testing problems and questionable results.

While the program is open to food manufacturers that formulate products with the sweetener, stevia extract producers, universities, and independent testing labs, the ISC suggests it is most relevant to parties interested in maximizing the accuracy of their steviol glycoside analyses.

So how has the program performed in its first months? In an interview with Nutritional Outlook, ISC executive director Maria Teresa Scardigli says it has been quite successful. Fifteen laboratories participated in the first round in May, and sixteen laboratories in the second round in August. The November round is expected to draw even more participants, and more activity is expected in 2012 following Europe’s approval.

“This program was instituted to help accelerate the development of robust testing methods to support a fast-growing set of ingredients entering the market,” said Scardigli. “It is the Council’s aim and belief that these types of programs help establish maturity and assurance in the market that steviol glycosides are able to be accurately measured and quantified for consistent use in food, beverage, and supplement markets around the world where they are approved for these applications.”

“All companies that are part of ISC are part of this program,” says Mary Lynn Shafer, manager of beverage strategy and business development at Corn Products International (Westchester, IL), a founding ISC member. “The significance of the Proficiency Testing Program is that all participants are able to benchmark performance of their methods, analytical standards, and competency in a statistical way that is relevant and managed in accordance with international quality standards. It is also an opportunity for customers to request that their suppliers participate in this to ensure a quality, consistent product.”

For more information on the International Stevia Council’s Proficiency Testing Program, visit www.internationalsteviacouncil.org

Stevia: Erythritol’s New Home

So long as stevia keeps snowballing, erythritol should maintain a comfortable place as one of its complementary sweeteners.

Zero-calorie erythritol has been used to sweeten North American food products since the late 20th century. The particular taste of this sugar alcohol offers what John Reidy, market management director for Jungbunzlauer (Newton, MA), calls an early-phase sweetness for stevia.

“When both natural sweeteners erythritol and stevia are used, they reveal very strong synergies in sweetness,” he says. “First of all, the sweetness of the blend is much stronger than expected, and secondly, erythritol manages to add sweetness in the early phase of the sweetness profile. Stevia’s sweetness comes in late, which is a problem especially at higher usage rates. Erythritol sweetness is sensed much quicker and it levels out the late sweetness onset of stevia.”

Only time will tell if food and beverage formulators can completely pull the bitterness from all stevia-sweetened products; until then, erythritol looks like it’s maintaining a stronghold within the stevia market. The most talked-about tabletop stevia sweetener, Cargill’s Truvia-which already rivals sales of Equal and Sweet’N Low-relies on erythritol, if not for taste enhancement, then for erythritol’s arguably more critical function: bulking.

Erythritol offers unparalleled structural support where stevia cannot. In Truvia, it is responsible for the granulated mimicking of sugar crystals, a structure which further performs in numerous products that otherwise rely on sugar’s structural support, such as ice creams and confectionery.

In an embrace of the marketwide popularity for stevia, erythritol suppliers are even shopping both ingredients in one. Jungbunzlauer provides one example: its Erylite brand erythritol can now be packaged with stevia.