Stevia steps up: Suppliers forge a path for a reduced-sugar world

The first wave of stevia to hit the market more than a decade ago made a serious splash. But as we learned in the part 1 of this series, splashes can be messy.

Some consumers soured on those early sweeteners, thanks to the bitter aftertaste and licorice off notes that cast doubt on stevia’s claim to being the “natural” sugar substitute we’d all been waiting for.

And in an irony we truly can call bitter, the culprit behind those flavor faults are the very steviol glycosides responsible for stevia’s remarkable sweetness in the first place

Is stevia fatally flawed? No. Its glycoside portfolio just needs a rebalance to emphasize the more palatable rebaudiosides — like rebs M and D — over the notoriously bitter reb A.

As Tom Fuzer, vice president of market strategy at HOWTIAN, put it, “In leveraging the full range of glycosides available, stevia-based solutions can offer functionalities very close to those of the sucrose gold standard. Stevia’s minor glycosides have made a huge step-change in these fields.”

Keep ‘em separated

So if leveraging glycosides is the surest strategy for improving stevia, what tactics are helping sweetener suppliers get there?

Advanced filtration is a great place to start, suggests Thom King, chief innovation officer at Icon Foods.

“The trick to making stevia less bitter is a matter of isolating the best-tasting rebaudiosides and then using a filtration process like double-resin bed technology to pull out the rebaudiosides that activate the bitter taste receptors,” he explained. “It’s a natural process that doesn’t use any chemicals.”

Fuzer also considers extraction the “most natural” route to stevia production — and that matters, he added, as “we don’t want to compromise on what consumers expect: an honest, transparent, leaf-based natural product.”

Start with the plant

Fortunately, Fuzer continued, “There’s so much more within the stevia plant that can improve sweetener production.”

That’s where improvements in plant breeding and agriculture come in, yielding varietals that by their nature produce more of the better-tasting rebaudiosides that were rare in earlier plant generations.                                                                     

Layn Natural Ingredients is exploring these advances, and as Doris Ip, the company’s marketing manager, explained, it all starts with tissue cultures from which the plant-development team teases out novel stevia strains.

“Developing these strains involves selective breeding and advanced agricultural practices to enhance sweetness profiles and reduce undesirable off-notes,” she said. “Facilities and technologies at our new stevia plant then help us make rare but better-tasting steviol glycosides in addition to reb M and reb D. These methods result in a superior stevia product that’s more palatable and cost-effective.”

Kurt Callaghan, director of global product portfolio, sugar reduction, and chief of staff at PureCircle, Ingredion Incorporated, noted that PureCircle was the first company to map the stevia genome, establishing a knowledge base the company still leans on to identify varietals with optimal genomic fingerprints.                               

As proof of concept, he pointed to PureCircle’s new PCS-13 varietal, which he claimed “delivers high yields and high quantities of the most sought-after steviol glycosides.”

Conversion rate

Callaghan added that PureCircle complements its varietal-development program with a biotransformation process that, using minimal processing, converts the reb A in natural leaf extracts into targeted glycosides.

Also known as enzymatic bioconversion, this method undergirds how Sweegen creates its Bestevia sweetener systems, too. As Casey McCormick, the company’s vice president of R&D, explained, they start with the agricultural leaf, treating the extract with native stevia enzymes fine-tuned to turn less-desirable rebaudiosides into sought-after ones.

That generates not only prized second-generation rebaudiosides like rebs M and D, but “third-generation” rebaudiosides E and I as well, McCormick said. The result: “a more sugar-like taste experience that mainstream consumers can appreciate, and at a competitive cost and scale.”

Fermentation

And now that precision fermentation’s revolutionizing everything from plant proteins to flavor production, it’s no surprise that stevia manufacturers are getting in on the action, too.

One example is the joint venture whereby Cargill and dsm-firmenich are using fermentation to produce their EverSweet stevia.

As Smaro Kokkinidou, principal food scientist at Cargill, explained, the process relies on a “specially crafted yeast” that’s been altered to ferment its feedstock not into ethanol but into rebs M and D, producing the raw materials for a better-tasting stevia at an advantageous price and scale.

And it does so while leaving a smaller carbon and resource-use footprint than either traditional stevia agriculture or bioconversion, Kokkinidou claimed, adding that the company commissioned a validated third-party life-cycle assessment to affirm EverSweet’s sustainable credentials.

It’s only natural

Fermented stevia can claim better green bona fides, but can it call itself natural? And can stevia produced via bioconversion do the same? The answer in both cases is complicated.

“Steviol glycosides produced by different technologies have created lots of regulatory confusion,” Fuzer conceded. “Regulatory bodies in different countries have adopted varying approaches, with some rather strict and others more liberal. Generally though, they’re all demanding more transparent and easy-to-understand labelling in line with consumers’ expectations.”

In the mix

And that argues in favor of bettering stevia using a more back-to-basics approach: blending.

“Stevia works best with other ingredients to provide the taste and mouthfeel consumers expect,” King said. “You need something that’s obviously sweet — which stevia is — but you also need something that can carry that experience all the way to the end, like allulose, or katemfe berry extract, also known as thaumatin.”

Thaumatin, King added, is a positive allosteric modulator that can potentiate stevia’s sweetness to the extent that it swamps off-notes without masking unwanted flavors.

To bring the mouthfeel of stevia-sweetened products closer to their sugar-sweetened counterparts, King suggested formulators try digestive-resistant maltodextrin, soluble tapioca fibers and fructooligosaccharides like inulin, which coat the palate and recreate the viscosity that goes missing when sugar levels drop.

Ip added, “A particularly effective approach we’ve validated is blending stevia with monk fruit extract, monk fruit juice and natural flavors like naringenin and phloretin. These combinations enhance the sweetness profile and create a more sugar-like experience, catering to consumers’ taste preferences and health needs.”

Best friends

But perhaps consumers’ health needs can make room for at least some sugar in the mix. After all, said Fuzer, when optimizing stevia, “It’s best to have some sugar in the formula. Reduction, not elimination.”

McCormick agreed. “Historically, consumers grouped products into one of two buckets: ‘diet,’ which had no sugar and used high-intensity sweeteners, or ‘regular,’ which had no high-intensity sweeteners and was sweetened with sugar,” he said. “It’s only been within the past few years that consumers have opened up to consuming products combining sugar with high-intensity sweeteners, and that’s made stevia a ‘best friend’ to a number of other ingredients. It need not stand alone.”