HerbalEgram

FWD 2 HerbalEgram

HerbalEGram: Volume 6, Number 1, January 2009

Australia and New Zealand Approve Stevia as a Food Additive

Stevia in the form of an extract of concentrated steviol glycosides was approved in October 2008 by the Foods Standards Authority of Australia and New Zealand (FSANZ) as a new intense sweetener (food additive) and flavor enhancer for use in certain specified foods in Australia and New Zealand.¹ Steviol glycosides can now be used in a wide range of foods and beverages that contain sugar, and can either be used in conjunction with sugar or intense sweeteners or as a total sugar or intense sweetener replacement. One reason for the decision was to help promote an efficient and internationally competitive food industry.

The latest formal and successful application for stevia food use approval in Australia was made in May 2004 (revised January 2006) by the Plant Sciences Group of Central Queensland University, Australia, and Australian Stevia Mills Pty Ltd.² There had been earlier applications from other parties in Australia in 1999 and 2001, which fell short of the data requirements and were later withdrawn.³

The latest application ran somewhat in concert with similar applications overseas, including in the European Union (EU). In 2004 the Joint Expert Committee on Food Additives (JECFA) of the Food and Agricultural Organization (FAO) and the World Health Organization (WHO) had endorsed the safety of the use of steviol glycosides as a food additive and recommended a temporary ADI (Acceptable Daily Intake) of 2 mg/kg bw (body weight)/day expressed as steviol.^3,4 Since 2004, further data has become available and been evaluated by JECFA and also Australia, and the ADI has been increased in June 2008 to 4mg/kg bw/day expressed as steviol.⁵ The ADI covers steviol glycoside mixtures with different ratios of stevioside/rebaudioside.

In its 63rd meeting JECFA estimated the intake of steviol glycosides to be 2-5 grams per day based on a 100% sugar replacement scenario.⁴ However, the committee agreed that predicted actual exposures would more likely be 20-30% of this value. Therefore, estimated dietary exposure was based on this assumption and compared with the ADI of 4 mg/kg bw (expressed as steviol equivalents).* [Editor’s note: based on a comment from a reviewer of this article: The JECFA finding was particularly significant and has the potential to provide a roadmap for the widespread use of stevia-based sweeteners throughout Europe and the United States. It is also noteworthy that the US FDA participated in the drafting of the JECFA document, and in late December 2008, the FDA issued letters of “no objection” regarding the self-affirmation of safety of stevia-based sweeteners to 2 major food manufacturers in the

United States

.]

The Plant Sciences Group, Central Queensland University, began investigations into stevia in 1999 and has been the recipient of Australian Rural Industries Research and Development Corporation (RIRDC) funding for specified stevia projects since that time. In 2006, two key objectives were to follow-up the FSANZ application and to develop analytical procedures to determine the concentration of steviol glycosides in plant materials.⁶ Earlier projects included monitoring trial plantings in selected regions in Australia (e.g., Queensland, Tasmania, Victoria). Some value was noted in the utilization, for example, of Australian tobacco-growing skills and sugar cane extraction technology.

Steviol glycosides are natural constituents of the plant Stevia rebaudiana (Asteraceae). The leaves contain 10 different steviol glycosides, of which 7 have been named in the JECFA monograph.7 The glycosides of principal interest for their sweetening property are stevioside and rebaudioside A.

The specification finalized at the 69^th JECFA (2008)⁵ meeting and published in FAO JECFA Monographs 5 (2008)⁸ requires not less than 95% of the total of the 7 named steviol glycosides on the dried basis (expressed as steviol). This monograph recognizes differences resulting from composition of the stevia leaves, influenced by soil and climate, and the extraction and purification processes used.

The 68^th JECFA concluded that steviol glycosides are sufficiently thermally and hydrolytically stable for food use, including acidic beverages, under normal conditions of processing/storage.

Steviol glycosides have a synergistic effect on taste when used in conjunction with other sweeteners and, when used in association with other flavors, act as a flavor enhancer, which alternatively can be used to reduce the level of flavoring used.

It would appear that commercial organizations associated with the cultivation of the plant material and the distribution of the finished product have collaborated to provide as wide an opportunity as possible for future product development. The monograph effectively permits steviol glycosides that can extend from the following range: 95% stevioside/0% rebaudioside to 0% stevioside/95% rebaudioside. This paves the way for intellectual property development in all stages of production and use.

As the stevia market expands, commercially available stevia products could potentially vary in composition from one manufacturer to another with respect to the relative ratio of the steviol glycosides. Normal stevia extract (if such exists) contains 3% to 7% rebaudioside C and dulcoside A, which are the components with a somewhat bitter aftertaste. Of the sweet glycosides, rebaudioside A is sweeter than stevioside (300 times sweeter than sucrose [table sugar] for rebaudioside A compared with 250 times for stevioside)⁶ and also has a more palatable taste profile, having less of the metallic/licorice taste often associated with steviol glycosides, and a reduced aftertaste. Consequently, different commercial preparations may have different culinary uses, and different brands of tabletop sweetener may taste differently to consumers.^†

Because steviol glycosides are a complex mixture derived from an herb and not a single substance, and because the JECFA monograph permits variability in production and profile, suppliers and manufacturers are encouraged to respectively provide or obtain details such as described in the United States dietary supplement industry’s Standardized Information on Dietary Ingredients (SIDI) protocol⁹ when documenting their material. Having such detail in an ingredient specification will help manufacturers repeat source steviol glycosides with the same sweetening/flavoring characteristics, thus limiting batch-to-batch variation in finished goods.

In the Final Assessment³ FSANZ does not prescribe analytical methods because, according to FSANZ, “this can inhibit method development and require the prescribed method to be used even though better, less costly or more sophisticated methods may be developed in the future.” FSANZ acknowledged implementation issues, but advised that its role “does not extend to developing or validating methods or determining specific arrangements for compliance monitoring.” This leaves manufacturers and compliance agencies with assay development challenges, particularly for complex food matrixes, something that was pointed out by compliance agencies when commenting on the prior FSANZ draft.³

Beverages (e.g., formulated beverages, carbonated soft drinks) were predicted to be the major contributors to steviol glycosides exposures because they are consumed in large volumes, but the versatility of stevia extracts for use in a wide variety of foods is significant. As the stevia market expands and diversifies, formulators will need to stay abreast of extraction processes and material specifications to ensure the flavor characteristics that they desire and settle on remain consistent. The JECFA monograph provides some latitude, which, for production, is too broad if a consistently flavored product is desired.

The allocated INS (International Number System for food additives) for stevia is 960.

To complete the Australia/New Zealand stevia story, simple preparations of stevia herb, such as aqueous or ethanolic dried leaf extracts, are eligible for use in medicines in Australia including listed complementary medicines. These simple herbal preparations may also be used in dietary supplements in New Zealand. However, more sophisticated extracts, such as the now food-approved “steviol glycosides” where the total glycoside content is required to be not less than 95%, do not comply with the Australian medicine regulatory interpretation of an “herbal substance.”¹⁰ Steviol glycoside materials with modified (from normal) ratios of stevioside or rebaudioside A will almost certainly not be viewed as herbal extracts and currently steviol glycosides are not specifically permitted in the New Zealand dietary supplement legislation.¹¹ Whether the steviol glycoside material can be used in an Australian medicine is dependent on the profile and production method of the specific steviol glycoside ingredient until such time as a formal application to use steviol glycosides in Australian medicines is approved.

—Sue Akeroyd

Sue Akeroyd is a regulatory consultant in Australia dealing with various types of foods and therapeutic goods, including herbal preparations. Contact: sueaker@tecspertise.com.au.

* The 63^rd JECFA¹² used the GEMS/Food database¹³ to prepare international estimates of exposure to steviol glycosides (as steviol). It was assumed that steviol glycosides would replace all dietary sugars, at the lowest reported relative sweetness ratio for steviol glycosides and sucrose, 200:1. The intakes ranged from 1.3mg/kg bw/day (African diet) to 3.5mg/kg bw/day (European diet). The committee evaluated estimates of exposure per capita derived from disappearance (poundage) data supplied by Japan and China. The committee also evaluated estimates of exposure to steviol glycosides based on the replacement of all dietary sugars in the diets for Japan and the USA. The committee concluded that the replacement estimates were highly conservative and that intake of steviol glycosides (as steviol) would likely be 20–30% of these values, well below the ADI now established of 4 mg/kg bw/day.

† It is constructive to compare stevia’s sweetness to commercial non-caloric sweeteners: Cyclamate is approximately 30 times sweeter than sucrose, aspartame 180 times, acesulphame-k 200 times, sucralose 600 times, alitame 2000 times.¹⁴

References

1.   FSANZ Gazette Notices. Amendment No. 103 (FSC 45). Available at : http://www.foodstandards.gov.au/standardsdevelopment/gazettenotices/amendment1039october4070.cfm. Accessed November 17, 2008.
2.   FSANZ Application A540 - Steviol Glycosides as Intense Sweeteners. Composite link to Initial (12-7-2005), Draft (5-23-2007) and Final (8-6-2008) Assessment Reports. Available at: http://www.foodstandards.gov.au/standardsdevelopment/applications/applicationa540stevi3096.cfm. Accessed November 17, 2008.
3.   Final Assessment Report. Application A 540. Steviol Glycosided as Intense Sweeteners. FSANZ. August 6, 2008. Available at: http://www.foodstandards.gov.au/_srcfiles/FAR_A540_Steviol_glycosides.pdf. Accessed November 28, 2008.
4.   WHO Technical report Series 928 Evaluation of Certain Food Additives. Sixty-third Report of the Joint FAO/WHO Expert Committee on Food Additives. 2005. Available at: http://whqlibdoc.who.int/trs/WHO_TRS_928.pdf. Accessed November 27, 2008.
5.   Joint FAO/WHO Expert Committee On Food Additives, Sixty-ninth meeting. Rome, Italy, 17-26 June 2008. Summary and Conclusions issued 4 July 2008. Available at: http://www.fao.org/ag/agn/agns/files/jecfa69_final.pdf. Accessed November 18, 2008.
6.   Midmore DJ, Rank AH. A new rural industry – Stevia – to replace imported chemical sweeteners A report for the Rural Industries Research and Development Corporation. August 2002. RIRDC Web Publication No W02/022 RIRDC Project No UCQ-16A. Available at: http://www.rirdc.gov.au/reports/NPP/02-022.pdf. Accessed November 23, 2008.
7.   JECFA. Steviol glycosides. In: Combined Compendium of Food Additive Specifications, 68th Meeting of the Joint FAO/WHO Expert Committee on Food Additives [Online Edition]. Rome, Italy: Food and Agriculture Organization of the United Nations (FAO). FAO/JECFA Monograph 4, pp. 61-64. 2007. Available at: http://www.fao.org/ag/agn/jecfa-additives/specs/monograph4/additive-442-m4.pdf. Accessed November 27, 2008.
8.   Steviol glycosides monograph history. Available at: http://www.fao.org/ag/agn/jecfa-additives/details.html?id=898.
9.   Joint Standardized Ingredient Information Protocol (SIIP) Working Group. Standardized Ingredient Information on Dietary Ingredients (SIDI). Available at: http://www.ahpa.org/SIDI/index.html. Accessed November 23, 2008.
10.   Therapeutic Goods Regulations 1990. Available at: http://www.comlaw.gov.au/comlaw/Legislation/LegislativeInstrumentCompilation1.nsf/0/E1AE934664C51864CA25747A001D45D1?OpenDocument. Accessed 11-29-2008.
11.   New Zealand Dietary Supplements Regulations 1985 (SR 1985/208). New Zealand. August 19, 1985.
12.   JECFA. Steviol glycosides. In: 63rd Meeting of the Joint FAO/WHO Expert Committee on Food Additives. Geneva, Switzerland: World Health Organization (WHO). WHO Technical Report Series 928, pp. 34–39 and 138. Available at: http://whqlibdoc.who.int/trs/WHO_TRS_928.pdf. Accessed November 27, 2008.
13.   The Global Environment Monitoring System - Food Contamination Monitoring and Assessment Programme (GEMS/FOOD).
14.   FSANZ Web Seminar (WEBinar) series. Available at: http://www.foodstandards.gov.au/_srcfiles/Webinar2_Sweeteners_010507.pdf. Accessed November 18, 2008.