While the best-known steviol glycoside - Reb A – can be extracted from the stevia leaf in commercial quantities, it has a bitter aftertaste that formulators have struggled to overcome in certain applications.
However, better-tasting steviol glycosides such as Reb M and Reb D are present in the stevia leaf in such tiny quantities (less than 0.5% by dry leaf weight) that it is not commercially viable or environmentally responsible (you’d need huge amounts of land devoted to stevia plants) to extract them from stevia leaves.
By using a genetically engineered baker’s yeast to convert sugars (Cargill is using corn dextrose as a feedstock but could use cane sugar) into these more desirable glycosides via a fermentation process, Cargill and Evolva can produce them on a commercial scale.
And while the production process has been getting more media attention than the products, the feedback from leading CPG companies suggests EverSweet could be a game-changer in the beverage industry as firms look to make more drastic reductions in sugar, Cargill’s global business development director Scott Fabro told FoodNavigator-USA.
The Holy Grail: zero calorie cola
If the first wave of Reb-A sweeteners enabled sugar reductions of 30%, and platforms such as Cargill’s ViaTech have since pushed the bar to 70% or more, Reb D and Reb M can deliver the Holy Grail in beverage formulation, a zero calorie cola, without any bitter aftertaste, he claimed.
Cargill has also used EverSweet in zero-calorie fruit waters, sweet teas, lemon-lime sodas and other products that have a full-bodied mouthfeel and sugar-like taste profile that is “just not possible” with the Reb-A based sweeteners currently on the market, he added.
- What is EverSweet? A new high-potency sweetener developed by Swiss synthetic biology pioneer Evolva and US ingredients giant Cargill comprising the steviol glycosides Reb D and Reb M (which are found naturally in the stevia leaf in very low concentrations).
- How is it made? In large fermentation tanks in Blair Nebraska, in which a genetically engineered baker’s yeast converts sugars (in this case, corn dextrose) into Reb D and Reb M. The yeast is completely removed from the final product, which is further concentrated and purified.
- How is it labeled? Reb M and Reb D/steviol glycosides/Rebaudioside M and Rebaudioside D.
- What are the potential applications? Everything from dairy to tabletop sweeteners and alcoholic beverages, but low or zero calorie beverages are the sweet spot.
- Is it safe? EverSweet is self-determined GRAS, and Cargill expects to get a letter of no objection from the FDA next year.
- When will it launch? 2016.
- When will the first products containing EverSweet hit shelves? Possibly as early as 2016.
“Some of the customers we’ve been talking to have sampled the peach water and said ‘I could launch this right now.’ If you wanted to achieve the same kind of SEV (sucrose equivalent value) we’ve got here and you’re using RA 95, you’d get a really bitter aftertaste. But we’ve got a full-bodied sweetness profile, more upfront sweetness, as you get with sugar, and a rounded taste.
“As the yeast strain we use produces both Reb D and Reb M, we also have no solubility issues, whereas Reb D on its own can present challenges as it is less soluble. It performs exceptionally well in diet sodas.”
Cheaper, greener, quicker
But why not focus your energy on breeding stevia plants with higher levels of Reb D and M so it’s viable to extract them from the leaf (stevia supplier GLG for example, claimed yesterday that it has already produced stevia varieties with Reb D levels of 1.26%, an increase of 320% over conventional varieties)?
Because it still involves devoting thousands of acres of land to growing plants containing minuscule levels of your target molecules, said Fabro, which doesn’t make environmental or economic sense.
And it could also collapse the Reb A market, which is leaf-derived, he claimed. “You’d collapse the market for the stevia farmers. If I make a commercially viable quantity of Reb M from the leaf, I’d produce so much Reb A that I’m going to obligate my customer to have to buy that. The amount of Reb A I’d produce in order to make 15-20 tons of Reb M is the size of the entire Reb A market globally right now, so I would just collapse that market.
“This is an add-on that opens up a new space and helps us address a market we can’t get to today from the leaf.”
While definitions of synthetic biology vary – and some firms feel the ‘synbio’ moniker is unhelpful as it has been co-opted by anti-GMO activists– the technique typically involves producing ingredients [eg. flavors, sweeteners, oils] in bioreactors via a fermentation process using micro-organisms such as algae or baker’s yeast with genetically engineered pathways that produce target molecules (eg. vanillin, Reb D) via the insertion of synthesized genes found in other plants or organisms, or through non-transgenic gene editing.
While this creates PR challenges, many leading ingredients and flavor companies are embracing the technology as it is cheaper, quicker and more sustainable than traditional production techniques such as synthesizing flavors from petrochemicals, or devoting thousands of acres of land to growing plants containing minuscule levels of target compounds.
Is EverSweet a ‘natural’ sweetener?
So are steviol glycosides produced via fermentation (rather than extracted from the stevia leaf) ‘natural’?
It depends on your definition, said Fabro, who says he is not being disingenuous, merely honest, given that the FDA has not clearly defined ‘natural’ and that everyone, from plaintiff’s attorneys in California to industry stakeholders, has a different perspective on this debate.
All Cargill can do is be “completely open and transparent” about how the sweeteners are made, and provide consumers, NGOs and food and beverage manufacturers with the information they need about the sweeteners (which can be listed as Reb M and Reb D; steviol glycosides; or Rebaudioside M and Rebaudioside D on the ingredients list), so that they can come to their own conclusions, he added.
“We’re not trying to disguise anything or mislead anyone. We’re not saying EverSweet is from the stevia leaf; we’re not using it in our Truvia stevia business [which uses steviol glycosides extracted from stevia leaves]; and we’re not even actually marketing it as stevia, even though the Reb D and Reb M we’re producing is chemically identical to what you’d extract from the leaf.”
He added: “If you’ve got a product that is built around an all-natural positioning, is this going to fit? Maybe not, we’ve got other options for you for that, but maybe you’ve got an artificial sweetener in your product and you’re under pressure to replace it, this gives you a new option that can deliver the same taste profile.”
We talked to consumers all over the country
As for ‘natural’ claims, fermentation is regarded by the FDA as a natural process when it comes to flavor production.
However, the agency has not specifically addressed the issue of how ingredients produced via microbial fermentation should be labeled or regulated if the micro-organisms in question have been genetically engineered, especially if so-called ‘synthetic biology’ is involved.
However, Cargill isn’t actively marketing EverSweet as a natural sweetener, and Fabro says it has worked extensively with consumers, NGOs, and customers to decide how to position it to keep everyone happy.
“We talked to consumers all over the country, told them what it is and how it’s made - and yes, we mentioned the words ‘genetically engineered’ – and asked them where they would see it on a continuum from natural to artificial, and most said it’s certainly not artificial, but I’m not sure I’d call it all-natural. I think the key thing for consumers, and NGOs, is that we don’t misrepresent it.
“On the label it will say steviol glycosides, or Reb D or Reb M, which is exactly what it is.”
Is it non-GMO?
When it comes to non-GMO labeling, meanwhile, the situation is equally confusing.
For example, EverSweet is technically GMO-free as the genetically engineered yeast used to make it serves as a processing aid, and is not present in the final product, meaning it would not require a GMO label in Europe, or in the US state of Vermont, which will introduce GMO labeling in 2016.
However, it wouldn’t pass muster with the Non-GMO Project (a widely-used voluntary standard), which says ingredients produced via ‘synthetic biology’ do not qualify for its Non-GMO Project Verified stamp, regardless of whether any GM material is detectible in the final product.
Friends of the Earth (FoE), meanwhile, has dubbed synthetic biology as ‘extreme genetic engineering ’ and is urging consumers, and food and beverage firms, to steer clear, despite the fact that the Reb D and Reb M produced by Cargill and Evolva is chemically indistinguishable from the Reb D and M in the stevia leaf.