Thaumatin: What It Is, and Why It's In Your Oats

4 min read · Sep 2026

You read the ingredients list. Fair enough, so do we. It's the last thing on there: Natural Sweetener (Thaumatin). Here's the two-minute version.

The short answer

Thaumatin is a natural sweet-tasting protein from a West African fruit. We use a very small amount of it so we can keep the added sugar down and still have the oats taste like something you want to eat.

What it actually is

Thaumatin comes from the katemfe fruit, native to Sudan and West Africa, where it's been used to sweeten food for generations.

It's a protein, not a carbohydrate, which makes it unusual among sweeteners. Your body digests it the way it digests any other protein.

It's also extraordinarily sweet. Food Standards Australia New Zealand puts it at roughly 2,000 to 3,000 times sweeter than sugar. A pinch does what a spoonful can't.

Why it's in our oats

Pea protein tastes like pea protein. That's the honest version. Plant proteins bring bitter and slightly metallic notes with them, and every plant-based product on the shelf has to deal with that somehow. The usual answer is sugar - a lot of it - to bury the taste.

Thaumatin does something different. At small amounts it works as a bitter blocker, smoothing out those off-notes rather than covering them. Which means we don't need much sugar to make the flavour work.

There is raw sugar in there - it's on the pack, second half of the list. Most flavours come in at 3-4g of total sugars per 90g pouch, and that figure includes the sugars that come from the oats themselves and, in Blueberry Maple, the fruit. A small amount of sugar plus a tiny amount of thaumatin, rather than a lot of either one.

No metallic aftertaste. Some sweeteners leave a sharp or lingering tang. Thaumatin is slower to arrive and longer to fade, which is why it sits better alongside real ingredients than it does standing in for them.

It's a plant protein. Extracted from fruit, not synthesised. It fits the rest of the pouch.

How thaumatin compares to other sweeteners

If you've ever put down a protein powder or a drink mix because of the aftertaste, the sweetener is usually why. Here's what the common ones do, purely as a matter of taste.

Steviol glycosides (stevia) - plant-derived and very sweet, with a finish a lot of people read as bitter or slightly licorice-like. It tends to sit at the back of the mouth and hang around. In delicate flavours it can take over.

Sucralose - synthetic, and the sweetness arrives fast and sharp. Clean for some people, lingering for others.

Erythritol and other sugar alcohols - these absorb heat as they dissolve, which is the cooling sensation you get on the tongue. Fine in mint, odd in vanilla.

Thaumatin - a protein rather than a glycoside or a sugar alcohol, so it behaves differently in the mouth. It arrives slowly, builds rather than spikes, and fades without a sharp edge. At small amounts it also blocks bitterness rather than adding any.

None of these is a villain. They're formulation choices, and different products want different things. For a breakfast you're eating cold, plain, first thing in the morning, we wanted a sweetener you'd forget was there.

OviOats contains no stevia, no sucralose and no sugar alcohols. What sweetens the pouch is a small amount of raw sugar, plus a trace of thaumatin.

The catch, for the sake of being straight with you: thaumatin costs considerably more than the alternatives. That's most of the reason you don't see it more often.

Is it safe?

Yes, and you don't have to take our word for it.

Thaumatin is a permitted food additive in Australia and New Zealand, listed in the Food Standards Code as additive 957. FSANZ classes it as an intense sweetener and notes that no Acceptable Daily Intake has been set for it because of its good safety profile - which is not something that's said about most sweeteners.

Every food additive approved for use here goes through a FSANZ safety assessment first. You can read their consumer page on intense sweeteners if you want the detail from the source rather than from us.

Quick answers

Is thaumatin natural or artificial? Natural. It's extracted from the katemfe fruit, not synthesised from other chemicals.

Is thaumatin a sweetener or a protein? Both. It's a protein that happens to taste intensely sweet - unusual, since most sweeteners are carbohydrates or synthetic compounds.

Does thaumatin taste like sugar? Close, not identical. It arrives slightly slower and lingers longer. Used in small amounts, it rounds out flavour rather than dominating it.

Is thaumatin approved in Australia? Yes. It's listed as additive 957 in the Australia New Zealand Food Standards Code and assessed as safe by FSANZ.

How much thaumatin is in OviOats? Very little. At 2,000–3,000 times the sweetness of sugar, it takes almost nothing - it's the last item on our ingredients list for a reason.

Is thaumatin vegan? Yes. It's derived from fruit.

Does OviOats contain stevia? No - no stevia, no sucralose and no sugar alcohols. The sweetness comes from a small amount of raw sugar and a trace of thaumatin.

Thaumatin vs stevia — what's the difference? Stevia is a glycoside; thaumatin is a protein. In practice, stevia's sweetness arrives fast and finishes with a lingering note many people find bitter. Thaumatin builds slowly and fades cleanly.