Key points
- No adverse effects have been seen in high-dose animal research
- No teratogenic or mutagenic effects have been observed
- No allergic sensitization has been observed after oral ingestion of thaumatin
Thaumatin is a natural, low-calorie sweetener isolated from the West African Katemfe fruit (Thaumatococcus daniellii Bennett). It is a mixture of sweet-tasting proteins, roughly 2000 times sweeter than table sugar with flavour modifying properties and a tendency to ‘build’ in sweetness leaving a longer-lasting perception of sweetness. These properties allow it to be used in far smaller amounts than sugar (equating to a near-zero net calorie sweetener) and for it to be used to mask flavours and ‘after-tastes’ in foods and supplemental foods (like protein powders and bars). In high doses though, it can also leave a liquorice-like aftertaste. As a sweetener and flavour modifier, thaumatin is highly soluble, and acid- and heat-stable. It has been used as an added sweetener and flavour compound since the 1970s.
Traditional use of thaumatin
Traditionally, katemfe has been used to flavour foods and beverages and references in the scientific literature can be found as far back as 1855 in an article published in the Pharmaceutical Journal; ‘Katemfe, or the miraculous fruit of the Soudan’,1 and a resurgence of interest in the plant and its extract beginning in the 1970s.2-5
Traditionally, katemfe has been used to flavour foods and beverages
[Note: There have recently been articles decrying the patenting of traditional African and other indigenous plant foods and extracts by multinational companies. E.g. https://www.thepatriot.co.zw/old_posts/the-value-of-traditional-medicines-and-herbs/]
Thaumatin is generally regarded as ‘safe’
Thaumatin has been approved as a sweetener in the European Union (as additive E957) and in Israel, and Japan. In the United States, it is generally recognized as safe (GRAS) as a flavouring agent (FEMA GRAS 3732) but not as a sweetener.
What does the research say about the safety of thaumatin?
In trials conducted in rats and dogs, thaumatin was shown to be readily digested before absorption, and no adverse effects were observed from the continual administration of either 0, 0.3, 1.0, or 3.0% solutions (over 13 weeks). Additionally, no development effects were observed on mice foetuses (days 6 to 15 of gestation) at doses up to 2000 mg/kg of body weight, or on cancer formation in male mice at the same dose (for 5 days). The lack of mutagenicity has been confirmed in bacterial research.
No developmental or pro-cancer effects have been observed
It is a weak allergen when administered systemically or by skin prick but not when taken orally and human studies have shown no allergic sensitization after oral ingestion of thaumatin.6
Human studies have shown no allergic sensitisation after oral ingestion
In its report on the Scientific Opinion on the Safety and Efficacy of thaumatin for all animal species, authors from The European Safety Authority concluded that 1-5 mg/kg of thaumatin protein is safe for all animal species “with a considerable margin of safety” and that “Thaumatins are highly digestible proteins and no residues in edible tissues/ products are expected. Consequently, there are no concerns for consumer safety.”7
Thaumatin protein is safe for all animal species “with a considerable margin of safety”
Conclusion
Thaumatin is a traditional food (in Katemfe) and sweetener and flavour-modifier that is now very commonly used without evidence of any adverse effects. There is no evidence of cancer or developmental risks arising from the use of thaumatin. While it may be a weak allergen when administered systemically, it is found to be completely inactivated when taken orally and so is unlikely to offer any allergen risk.
Based on the evidence, thaumatin is a safe low-calorie sweetener.
References
1. Daniell WF. Katemfe, or the miraculous fruit of Soudan. Pharmaceutical Journal. 1855;14:158-9.
2. Van der Wel H, editor Miracle fruit, Katemfe and serendipity berry. Symposium: Sweeteners; 1974: AVI Publishing Co., Westport, CO.
3. Nicol W. The serendipity berry and katemfe—natural protein sweeteners from West Africa. Nigerian Field. 1976;41:150-5.
4. Agathi KB, Thonine P, Reisfeldpflanze RO, Ngo R, Santol K, Erdbohne K, et al. K 348 katemfe.
5. Wel H, editor Miracle fruit, katemfe, and serendipity berry. Symposium Sweeteners GE Inglett, ed; 1974.
6. Higginbotham J, Snodin D, Eaton K, Daniel J. Safety evaluation of thaumatin (Talin protein). Food and chemical toxicology. 1983;21(6):815-23.
7. Panel on Additives Products or Substances used in Animal Feed E. Scientific Opinion on the Safety and Efficacy of thaumatin for all animal species. EFSA Journal. 2011;9(9):2354.
