Stevia’s Evolution

By Cindy Hazen

Just as consumers’ food preferences are shifting toward healthier choices, natural sweeteners are evolving to meet the demand for clean eating.  Expectations for simple, understandable ingredients are in vogue. Concurrently, palates have become more refined. Clean is not only a word that applies to labels, it also means to today’s consumers, free from off flavors, low in sugar, and moderate in fat and calories.  Foods must enhance wellbeing, and they must be delicious.

Stevia is at the forefront of plant-based sweeteners. It’s high intensity. Such minute quantities are used that it doesn’t contribute calories. Despite the fact that it’s an obvious contender for replacement of sugar and artificial sweeteners, the trajectory to the front of the pack has been anything but smooth.

For one, stevia is not a single component. The term refers to sweet compounds found in the stevia leaf. Extracts are derived from leaves of the South American plant Stevia rebaudiana.  More than 10 different sweet steviol glycosides are found within the stevia leaf.  Rebaudioside A (Reb A) is the best known. Steviol (aglycone), Stevioside, Dulcoside A, Rubusoside, Rebaudioside B, D, E, and F follow. Science continues to not only discover new compounds, but more importantly to food scientists, identify their potential as a sweetener. Research continues to hone in on exact glycosides no matter how small their presence in the leaf. Rebaudioside M, also known as Rebaudioside X, is a relatively new player.

The challenge is greater than finding a single component or even a combination. Flavor of stevia products varies immensely because of the disparities of concentrations and purity of these glycosides. Growing conditions, including soil, water and weather will determine the composition and strength of the plants. Finally, the means of extraction — natural water extraction or petrochemical extraction — impact the final taste.  Unlike a commodity like sugar, one company’s product can’t be simply substituted for another Because of the enormity of the variations among products, the choice of stevia supplier is critical to quality control.

Since early incarnations stevia products have matured, resulting in purer, more consistent products.  Today’s extracts are exceptionally clean. They are a sharp contrast to early generations of stevia that had a distinct licorice-like flavor and a slight perception as bitter. To many, depending on the application, they had an off-putting quality, affecting some with an unpleasant aftertaste. While stevia has made exceptional inroads in flavor and quality, it’s still important that these products be used in an appropriate application.

As a high-intensity sweetener, stevia is not meant as a drop-in replacement for sugar. It’s used at such low levels that it cannot provide the fullness that sugar provides to the flavor profile and to the formulation. When paired with a bulking agent, such as erythritol, body, and mouthfeel are developed. The flavor becomes more rounded. But, a word of caution. If paired with other flavors that lean toward bitter, undesirable notes might emerge.

The food scientist must understand every nuance of the ingredients in the formulation, not only as they exist as added in raw form, but also how they will interact with other ingredients. Will they accentuate the positive in each or become combative? And achieving balance is not immediate. Manufacturing processes and storage conditions, as well as the length of shelf-life, will affect the overall flavor and stability of the product.

Starting with a clean flavor profile goes a long way toward developing and maintaining a balanced profile.  That’s where stevia’s evolution comes in.

Rebaudioside M is new to the scene. It’s considered a minor steviol glycoside, perhaps even novel because it is present at a low level in the stevia leaf. Its isolation and molecular structure have only come to light in recent years. FDA has issued a Letter of No Objection concerning its Generally Recognized as Safe status.  However, extraction from the leaf is impractical because it is present in such small concentrations. Work at MIT has developed a scalable fermentation process to make the compound in commercial quantities. Plant breeding is underway to create stevia plants with higher yields. Another process uses enzymes to convert stevioside into Rebaudioside M.

As a sweetener, Rebaudioside M is a game changer. By itself it demonstrates a prolonged sweetness, however, when paired with Rebaudioside A, the result is an exceptionally smooth sweetness profile.

Icon Foods brings together these two stevia components in a next-generation sweetener. The highest grade of Rebaudioside A (99 percent) is paired with the highest purity of Rebaudioside M currently available (95 percent). The result is a synergistic effect that is greater than either demonstrates alone. Licorice and bitter notes are reduced. Rebaudioside M works as a sweetness modulator or masker for whatever small off-notes might be present with the Rebaudioside A.

This new product, RA99M, is about 350 times sweeter than sugar. While it has superior attributes, because of its potency it must be used at very low levels. In RTD applications its recommended use is less than 0.1 percent. It has also shown success in powdered drink mixes. Whenever using high-intensity sweeteners, it’s best to begin on the side of caution. Rather than start at the high end, begin with a very low level and gradually increase levels in the formula until the desired sweetness is achieved.

Although consumers are looking for sugar replacements, none yet exactly clone sugar’s taste. However, RA99M raises the bar and sets a new standard for products with clean labels and clean flavor.