Innovative Brazzein – The Sweet Protein That Survives Baking and Sterilisation

CONFECTIONARY

Harleen Singh

5/15/20263 min read

This is an AI generated illustration and does not represent actual product or service.

A naturally ultra‑sweet protein from a West African fruit normally falls apart above 80 °C. A single amino acid change now lets it withstand temperatures above 110 °C – opening the door to sugar‑free cakes, sterilised drinks, and baked goods that actually taste sweet.

That’s the promise of a newly published international patent (WO 2026/082847 A1) from researchers at the Technical University of Denmark and the University of Washington. They’ve engineered a variant of the sweet protein brazzein that stays intact and sweet even after being heated to temperatures that would destroy the natural version.

The Problem: Sweet Proteins That Can’t Take the Heat

Brazzein is one of eight known sweet proteins found in tropical plants. It is naturally 500 to 2000 times sweeter than sugar on a weight basis, adds almost no calories, and doesn’t spike blood glucose. That makes it an ideal natural sweetener – except for one fatal flaw: it denatures at around 80 °C.

Most food processing involves much higher temperatures:

Baking – often above 150 °C
UHT sterilisation – 135–140 °C
Pasteurisation – 72 °C for 15 seconds (okay for liquids, but not for baking)

Once the protein unfolds, it loses its sweetness. That’s why you don’t see brazzein‑sweetened cookies or canned iced coffee – the heat kills its function.

The Solution: One Smart Substitution

The patent describes a series of brazzein variants, but the star is a single‑amino‑acid change: replacing histidine at position 31 with asparagine – abbreviated H31N.

In the lab, the researchers measured the melting temperature (Tm) – the point at which half the protein is denatured. For native brazzein, the Tm was 106 °C. For the H31N variant, the Tm was above 110 °C – so high that the instrument couldn’t measure it directly. Using extrapolation (adding a denaturant to lower the Tm and then calculating back), they estimated a Tm of 107.9 °C, but direct measurement exceeded the instrument’s 110 °C limit. In practical terms, the variant remains folded and sweet at temperatures that would destroy the original protein.

For comparison, another variant (H31A) had a Tm of only 96 °C, and H31R was 105.2 °C – showing that not just any change works. Asparagine at position 31 is uniquely effective.

Does It Still Taste Sweet?

Crucially, increasing thermostability didn’t ruin the sweetness. In a sensory test with 61 participants, the H31N variant was rated just as sweet as native brazzein (p = 0.2476, not statistically significant). The ranking and rating methods both showed that people couldn’t tell the difference in sweetness intensity.

The patent also describes a triple mutant (Y8F/Y11F/G35A) that also exceeded 110 °C, but the H31N single mutant is the simplest and most elegant solution.

How Was It Made?

The researchers expressed the variants in Saccharomyces cerevisiae (baker’s yeast) and Komagataella phaffii (another yeast used for protein production). They used a standard purification approach (nickel affinity via a His‑tag, followed by cleavage) and measured thermostability with nano differential scanning fluorimetry (nanoDSF) – a technique that tracks protein unfolding by monitoring tryptophan fluorescence as temperature rises.

The data clearly show that native brazzein unfolds completely below 110 °C, while the H31N and triple mutant remain folded even at the maximum temperature.

Why This Matters for Food & Drink

With a thermostable sweet protein, manufacturers could potentially:

Bakery products – cakes, biscuits, muffins that are sweet without sugar or artificial sweeteners.
Sterilised beverages – canned coffee, iced tea, shelf‑stable dairy drinks that undergo UHT treatment.
Baked snacks – protein bars, granola, breakfast cereals that are heated during production.
Hot drinks – sweeten your coffee or tea without adding sugar or worrying about the protein denaturing.

The patent explicitly mentions “foods, feed and/or beverages that are heated for example to temperatures between 80 and 120 °C during preparation or prior to consumption, such as temperatures between 80 and 110 °C, for example between 100 and 115 °C, such as between 105 and 112 °C.”

What About Other Sweet Proteins?

Brazzein is already one of the most heat‑stable natural sweet proteins (thaumatin, for example, denatures at lower temperatures). By pushing its Tm above 110 °C, the inventors have made it compatible with virtually all food processing except extreme high‑heat treatments. It’s a significant advance over previous efforts.

The Bottom Line

A single amino acid change – histidine to asparagine at position 31 – transforms brazzein from a sweetener that can only be used in cold or mildly warm products into one that can survive baking and sterilisation. And it does so without losing any of its natural sweetness.

If this technology reaches the market, you might soon be eating a sugar‑free cookie that tastes just as sweet as the real thing – and stays that way after coming out of the oven.

Patent number: WO 2026/082847 A1
Applicants: Danmarks Tekniske Universitet, University of Washington