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Thaumatin: the Natural Sweetener You Need to Try

Diet & Nutrition Education Thaumatin

Ever wondered how Clean Lean Protein by Nuzest gets its sweet taste without artificial sugars? The answer is thaumatin: a low-calorie sweetener and flavor modifier. The protein is primarily for its flavor-modifying properties and not exclusively as a sweetener.¹


Have you ever heard of thaumatin? If not, then read on to learn about this natural low glycemic index sweetener. Thaumatin is a low-calorie protein sweetener and flavor modifier from the katemfe fruit, a fruit found on the Thaumatococcus daniellii plant common to the West African rainforest.


Each fruit contains three large, shiny black seeds surrounded by transparent jelly. The aril contains the thaumatin, which has long been used as a culinary sweetener.


Recently, it has become an increasingly mainstream natural low glycemic index sweetener alternative to many artificially-produced low-calorie sweeteners on the market. It’s popular in Japan and throughout Europe in diet drinks and snack foods.


Table of Contents

What is Thaumatin?


The thaumatins were first found as a mixture of proteins isolated from the katemfe fruit (Thaumatococcus daniellii) originally from Ghana, West Africa. Some proteins in the thaumatin family of sweeteners are roughly 2,000 times more potent than sugar. Although very sweet, it's taste is significantly different from sugar's taste; the sweetness builds very slowly. Perception lasts a long time, leaving a licorice-like aftertaste at high usage levels. It is highly water-soluble, stable to heating, and stable under acidic conditions. Within West Africa, the katemfe fruit has been locally cultivated and used to flavor foods and beverages for some time. The fruit's seeds are encased in a membranous sac, or aril, that is the source of thaumatin.


Thaumatin has been approved as a sweetener in the European Union (E957) and elsewhere. In the United States, it is a Generally Recognized as Safe flavoring agent (FEMA GRAS 3732). 


How is Thaumatin Different from Sugar?


Unlike most sweeteners, thaumatin is a protein, not a carbohydrate. Proteins, like carbohydrates, contain 4 calories per gram.


However, thaumatin has such a high potency sweetness relative to sugar (roughly 1600-2000 times sweeter than table sugar) that only a tiny amount is needed to sweeten foods. The amount of calories added to a food when thaumatin is used as a sweetener is negligible.


Thaumatin is also used to enhance flavors and mask bitterness2. Although quite sweet, its sweetness builds slowly. It is metabolized by the body similar to any other dietary protein.


Is Thaumatin Safe?


Thaumatin has been tested for safety3 in both animal and human models and is considered safe at levels normally consumed by humans.


How Does it Impact Blood Sugar?


Because thaumatin is a protein, not a carbohydrate, it is metabolized differently than most sweeteners and has a different impact on blood sugar.


Rat studies4 have shown that thaumatin does not elevate blood glucose, nor impact body weight. Some sugars, including refined sugar, could raise plasma glucose levels that are known to lead to blood sugar spikes.


Table sugar contains 4 calories per gram. When used as a sweetener, sugar can add quite a significant amount of calories to the diet without offering much other nutrition other than fast energy.


Who Should Try It?


Many prefer this sweetener to artificially created low-calorie sweeteners such as aspartame and saccharin. Others enjoy it for its long-lasting sweet flavor and flavor-enhancement capabilities. It is a wise choice to sweeten foods having to frequently monitor your glucose.


Where Can I Find Thaumatin?


While it is still a bit more difficult to find than many sweeteners at local grocery stores, this natural sweetener can be found in some natural grocers and online. Thaumatin is used to sweeten Nuzest products, including Clean Lean Protein. Give it a try for yourself.



  1. Green C (1999). "Thaumatin: a natural flavour ingredient." World Rev Nutr Diet. World Review of Nutrition and Dietetics 85: 129-32.

Img Attribution: Cyriac Gbogou, CC BY-SA 4.0, via Wikimedia Commons / background desaturated from original