Playing with stevia aftertaste
December 22, 2009
by Jeff Gelski
Stevia extract suppliers often promote a high content of rebaudioside A (Reb A), known as the best-tasting steviol glycoside inside the stevia plant leaf. Reb A may comprise 95% or more of a natural, zero-calorie high-intensity sweetener made from stevia plants. Yet the remaining steviol glycosides, though small in content, may have the biggest impact on aftertaste.
“What we know is it’s not so much the Reb A number,” said Mel Jackson, vice-president of science for Sweet Green Fields L.L.C., Bellingham, Wash. “It’s what the other 5% is.”
Two sweeteners both may have Reb A content of 95% and still have different aftertastes, said Angela Palmieri, business development manager for GLG Life Tech Corp., Vancouver, B.C. One sweetener may taste better because the other sweetener has more bitter-tasting steviol glycosides among the remaining 5%.
“A tiny difference in a couple of percentage points in what is left over can make a difference (in taste),” Ms. Palmieri said. “We really emphasize taking out the unpleasant flavor notes.”
Rebaudioside C, for example, is distinctively bitter, she said. GLG Life Tech uses proprietary extraction technology to leave out such bitter notes, she said.
Stevioside has a good flavor as do some other steviol glycosides, including dulcoside and rebaudioside B, said Jim May, founder, president and chief executive officer of Wisdom Natural Brands, Gilbert, Ariz.
Ms. Palmieri said, “There are strains of the stevia leaf that are dominant in steviosides. It’s pretty positive tasting, but Reb A is still the gold standard for taste.”
As is the case with many high-intensity sweeteners, avoiding a licorice-like or bitter aftertaste will be vital to the success of stevia-based sweeteners. “Stevia and the U.S. Market,” a Rabobank report released in August, said annual U.S. sales of Reb A may reach about $700 million within five years although hurdles, including unwanted aftertaste, must be overcome.
Sixty-eight per cent of respondents rated taste as a high concern or moderately high concern in “Global Stevia Industry Perceptions Report 2009,” a survey authored by KnowGenix that ran from Aug. 22 to Oct. 22 and involved 334 stevia industry representatives from 77 countries.
An untrained consumer panel may start to notice differences in taste at a Reb A content level of 80% and higher, said Ron Deis, vice-president of applications research and technical service for Corn Products U.S. and based in Newark, Del.
Sensory charts see differences in profiles from 70% up to 90% or 97%, said Jason Hecker, director of marketing for PureCircle, which has a U.S. office in Florham Park, N.J.
“When we get much higher than that, we don’t really see much of a difference in sensory profiles,” he said.
PureCircle offers a stevia extract sweetener that is guaranteed to have Reb A content of 97% or above.
Corn Products International, Westchester, Ill., offers an Enlighten brand sweetener that contains high levels of Reb A. The company has a long-term agreement with Morita Kagaku Kogyo Co. Ltd., Osaka, Japan, for the exclusive license of a patented stevia strain, manufacturing technology and stevia production, along with global marketing and distribution rights. The Japanese company, involved in stevia extracts since the 1970s, offers a Morita RA95 sweetener with a high concentration of Reb A.
GLG Life Tech recommends its RA 97, which has 97% Reb A content, for use as a sweetener in foods and beverages, said Jim Kempland, vice-president of marketing.
Companies may vary in the extraction processes they use to reach a certain Reb A level.
Sweet Green Fields uses fermented ethanol that is Generally Recognized As Safe (GRAS) for use in food, said Mike Quin, senior vice-president of sales and marketing. The ethanol does not change the chemical nature of the molecule. It is used as a mechanical aid in getting the Reb A away from the unwanted steviol glycosides.
“From a consumer perspective, if you are positioning a product as an all-natural sweetener, at the end of the day the consumer is fairly interested in how you made the product,” Mr. Quin said.
Unlike Wisdom Natural Brands, other companies may use methanol or ethanol to alter glycosides in the production of high-intensity sweeteners from the stevia plant, Mr. May said. He added that he believes the use of such chemicals may give stevia extract sweeteners a bad aftertaste.
Wisdom Natural Brands uses water in its extraction process.
“No chemicals whatsoever touches our product,” Mr. May said.
Mr. May has been involved in the stevia industry for 28 years. Wisdom Natural Brands began selling a SweetLeaf stevia product as a dietary supplement in 1995. He said he advises consumers to know differences exist in stevia-based sweeteners.
“Look, if you try one brand and don’t like it, try another,” he said. “Don’t just try one and give up.”
Food and beverage companies may not have that luxury. If they choose a sweetener that leaves an unwanted aftertaste in their product, consumers may not give that product a second chance.
Sucralose sales steam ahead
While Tate & Lyle, P.L.C. recorded growth in the sales of its high-intensity sweetener sucralose so far this year, J.K. Sucralose made plans to expand its sucralose manufacturing capacity. The moves of the two companies contradict responses to “Global Stevia Industry Perceptions Report 2009.”
Respondents said they believe stevia-based high-intensity sweeteners will capture more than 50% of the market shares of aspartame, another high-intensity sweetener, and sucralose. The survey authored by KnowGenix ran from Aug. 22 to Oct. 22 and involved 334 stevia industry representatives from 77 countries.
Yet London-based Tate & Lyle said sucralose sales increased by 15% in volume and 9% in value in constant currency for the six months ended Sept. 30. Iain Ferguson, chief executive officer for Tate & Lyle, noted a price difference between sucralose and stevia-based sweeteners in an earnings conference call in May.
“I don’t think it’s so much a direct competitor for sucralose to be honest,” he said. “I think it’s probably got a niche of its own in areas where customers, consumers, brands want to develop a natural profile.”
Tate & Lyle has a direct competitor in J.K. Sucralose. The company has planned a 300-tonne sucralose capacity expansion project in The People’s Republic of China after an International Trade Commission judge this year ruled the production process of J.K. Sucralose does not infringe on Tate & Lyle patents.
Listing Reb A content
Suppliers of high-intensity sweeteners extracted from the stevia plant often promote the rebaudioside A (Reb A) content because of flavor benefits:
Blue California — The Reb A content of this company’s sweetener is 97% or greater. The Food and Drug Administration in a July 20 letter said it had no questions about the Generally Recognized As Safe (GRAS) status for use of the sweetener in various foods and beverages.
Cargill — Reb A content in the sweetener is 97% or more. The F.D.A. on Dec. 17, 2008, said it had no questions about the GRAS status of the sweetener for use in various foods and beverages.
Corn Products International — An Enliten brand sweetener contains high levels of Reb A, according to the company. An independent scientific panel review confirmed the self-affirmed GRAS status of Enliten.
GLG Life Tech Corp. — The company offers Rebpure (RA 97) that is 97% Reb A. GLG Life Tech also has supplied Cargill with high-grade stevia extract that has been used in Cargill’s Truvia tabletop sweetener.
PureCircle — The company has contracts with PepsiCo, Inc. and Whole Earth Sweetener Co. L.L.C. to supply Reb A and exclusive license to market Reb A under the PureVia brand. PureVia is 97% Reb A. PureCircle also has supplied Cargill with Reb A.
Sunwin USA, L.L.C. and Wild Flavors — These two companies sent two GRAS notices to the F.D.A. that were filed on Sept. 24. The notices are pending. One involves the use of Reb A purified from the leaves of Stevia rebaudiana Bertoni for use as a general purpose sweetener in various food categories. The other notice involves the use of purified steviol glycosides with Reb A and stevioside as the principal components for use as a general purpose sweetener in various food categories.
Sweet Green Fields L.L.C. — Reb A accounts for 97% or more of the content while other steviol glycosides are 3% or less. The F.D.A. in an Aug. 11 letter said it had no questions about the GRAS status of the sweetener for use as a general purpose sweetener in foods, excluding meat and poultry products.
Whole Earth Sweetener Co. L.L.C. — The content of the company’s sweetener is 95% or more Reb A with limits for stevioside of under 2% and for steviol of under 0.005%. The F.D.A. on Dec. 17, 2008, said it had no questions about the GRAS status of the sweetener for use in various foods and beverages.
Wisdom Natural Brands — Reb A and stevioside account for 86% to 90% of the steviol glycoside content of this company’s sweetener. Other steviol glycosides, including rebaudioside C and dulcoside A, also may be present. The F.D.A. in an Aug. 28 letter said it had no questions about the GRAS status of this sweetener for use as a general purpose sweetener in foods, excluding meat and poultry products and infant formulas.