Stevia IP battle: Sweegen prevails in four-year-long patent dispute with PureCircle over Reb M; Ingredion to appeal

By Elaine Watson

- Last updated on GMT

Image credit: Istockphoto-bdspn
Image credit: Istockphoto-bdspn

Related tags Sweegen Purecircle Ingredion Stevia

A court has found in Sweegen’s favor following a four-year legal battle with rival PureCircle over IP relating to the manufacture of stevia sweetener Reb M.

While Reb M can be extracted from stevia plants (which contain 40+ steviol glycosides that can be used as sweeteners and as flavor modifiers), it is typically found in very low percentages, prompting firms to explore techniques to produce it more cost effectively via genetically engineered microbes, or to use enzymes to convert more abundant steviol glycosides extracted from stevia leaves into scarcer ones such as Reb M via a bioconversion process.

The legal spat began in 2018* when PureCircle (now owned by Ingredion) accused California-based Sweegen of infringing a patent (U.S. Patent 9,243,273​) covering the manufacture of Reb M through a bioconversion process involving an enzyme called UDP-glucosyltransferase.

According to PureCircle, Sweegen’s Bestevia Reb M sweetener is manufactured via a bioconversion process developed by partner Conagen that PureCircle claims infringes patent ‘273.

Setback at the USPTO in 2019, but court ultimately finds in Sweegen’s favor

In late 2019, it looked as if PureCircle might prevail, after the US Patent Office’s Patent Trial and Appeal Board issued a decision in PureCircle’s favor​ (it denied Sweegen’s request for an inter partes review of the ‘273 patent as it felt Sweegen had not demonstrated a reasonable likelihood that claims in the patent would be invalidated).

After four years of back and forth, however, the US District Court for the Central District of California in Santa Ana has just concluded that the claims in PureCircle’s ‘273 patent and a related patent (the ‘257 patent) are in fact “patent ineligible as a matter of law.”

As it is impossible to infringe an invalid patent, the court's May 24 judgment effectively ends the litigation, said Sweegen CEO Steve Chen, adding that the firm had “always maintained that PureCircle's patents were invalid and its case against Sweegen spurious​.”

He told FoodNavigator-USA: "Our belief in the strength of our intellectual property is the foundation for the innovation that drives our relentless pursuit of unique technologies for sugar reduction. In the last four years, belief in our IP has supported the growth of our proprietary portfolio of Signature sweeteners, and enabled Sweegen to explore uncharted territory with the commercialization of sweet proteins such as brazzein and thaumatin."

Ingredion to appeal

Ingredion (PureCircle), however, told us it was “disappointed with the court’s ruling​” and intends to “file an appeal to continue to vigorously defend our intellectual property.”


The stevia sweeteners market has become more complex in recent years, with...

  • sweeteners extracted from stevia leaves;
  • sweeteners made with stevia leaf extracts as a starting material that then undergo an enzymatic conversion process to get to the better tasting steviol glycosides such as Reb M;
  • sweeteners such as Reb M made via fermentation of sugars with genetically engineered microbes (Cargill and DSM have teamed up in this space to make 'Eversweet' Reb M​​​ via the Avansya​​​ joint venture; while Ingredion has the exclusive license to sell and market Amyris’s 'Realsweet' Reb M​, which is also produced via fermentation).

While this 'fermented' Reb M does not involve stevia leaves at all, so can't be described on food labels as a 'stevia leaf extract,' it is chemically identical to the Reb M found in the stevia plant, and can be described in several different ways on food labels (Reb M, stevia Reb M, steviol glycoside etc).

Stevia in the courts

Multiple lawsuits have been filed over stevia IP in recent years, with PureCircle filing several complaints against firms it claims violated its patents.

A patent infringement complaint​​​ filed by PureCircle against Sweet Green Fields (SGF) in 2017 was resolved​​​ in early 2018 when SGF signed a license agreement with PureCircle; while a case filed by PureCircle vs Almendra in 2020 was settled the following year after Almendra signed a license agreement with PureCircle enabling it to continue selling its Steviarome flavor ingredients worldwide.  

In some cases, the parties suing each other are also working together.

Ingredion, for example, used to distribute stevia ingredients for Sweegen, with whom it became embroiled in the above dispute (via PureCircle, which is owned by Ingredion).

Ingredion also sued Sweegen directly in June 2019 alleging it had violated their distribution agreement by doing its own direct marketing, but resolved the dispute via arbitration the following month.

In 2020, meanwhile, Japanese stevia pioneer Morita Kagaku Kogyo Co took the unusual step of issuing a press release highlighting the extent of its IP around Reb M and naming the three partners to which it has licensed its technology (Cargill/DSM JV Avansya, Ingredion, and Tate & Lyle), “to send a clear message to the market​ to respect the related IP.”

In the release, Morita claimed that “Rebaudioside M… was discovered by the pioneer of stevia, Morita Kagaku Kogyo Co., Ltd., based in Japan, as a result of many years of stevia plant breeding efforts.”

*The case is PureCircle USA Inc., et al. v. Sweegen, Inc., et al., case number 8:18-CV-01679-JVS-JDE, in the United States District Court, Central District of California, Southern Division.       

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