Humanity has a long history with sweetness. We started with honey, moved to cane sugar, then engineered artificial sweeteners and sugar alcohols to chase that same taste with fewer consequences. Each generation of sweetener came with its own tradeoffs—calories, blood sugar spikes, gut disruption, aftertaste, or some combination of the above.
Now there’s a new category entering the conversation: sweet proteins.
They’re not sugar. They’re not artificial. They’re not sugar alcohols. They’re an entirely distinct class of molecule—proteins that happen to taste sweet. And while that might sound like science fiction, the science behind them is very real.
So what exactly is a sweet protein? Let’s start with what published academic research actually tells us.
How We Taste Sweetness
Here’s the thing about sweetness: it’s not exclusive to sugar. Sweetness is a biological signal—a trigger that fires when the right molecule interacts with the right receptor. And it turns out that receptor has multiple regions where different compounds can bind, which is precisely why such a wide variety of molecules—from simple sugars to complex proteins—can all trigger sweet perception.
The science behind this comes down to a single receptor system: the T1R2/T1R3 heterodimeric receptor. In 2025, Juen et al. published the first cryo-EM structure of the human sweet receptor, describing how “a single sweet receptor recognizes the diverse universe of sweet-tasting compounds, including natural sugars, artificial sweeteners, D-amino acids, and a class of intensely sweet proteins.”
What makes this receptor so versatile is its architecture. Different sweet compounds interact with different regions of the receptor, and multiple interaction models exist. These multiple binding regions are what allow such a structurally diverse range of molecules to activate the same receptor—and why proteins, despite being nothing like sugar, can still taste remarkably sweet.
What Are Sweet Proteins?
Sweet proteins are naturally occurring proteins that elicit a sweet taste in humans. Because they are proteins, they are subject to normal digestive processes. Studies on specific sweet proteins have shown they can be broken down by digestive enzymes. And they can be significantly more potent than sucrose in many applications, allowing sweetness to be delivered at much lower concentrations.
What makes them fascinating from a scientific standpoint is the sheer diversity among them. The sweet proteins discovered to date show a wide range of size, structure, and the species from which the protein is discovered—and notably, they do not share significant sequence or structural similarity.
Sensory Properties: What Studies Show
In the literature, sweet proteins are described as high-intensity sweeteners effective at very low concentrations. However, sweetness perception is not fixed—it is application-dependent and influenced by concentration, the food or beverage formulation, and the protein’s structure.
These studies characterize how sweet proteins behave under controlled conditions. They do not predict consumer acceptance or claim equivalence to sugar.
Great Science Is Just the Starting Line
Discovering sweet proteins and understanding how they interact with our taste receptors is one thing. Actually producing them at scale is another challenge entirely.
Academic research has documented significant hurdles in expression systems, protein stability, and cost-effective manufacturing—challenges that sit between laboratory discovery and a finished ingredient.
This is where applied science picks up where academic research leaves off. Translating a sweet protein from a published finding into a viable ingredient requires rigorous work: you need to identify the protein sequence and structure that creates the sweetness, make it at a large scale, and then demonstrate that a produced version behaves the same way as the native form.
Which brings us to the honey truffle.
Honey Truffle Sweet Protein
Mattirolomyces terfezioides—commonly known as the honey truffle—has long been recognized for its sweet taste. But until recently, the specific molecule responsible hadn’t been pinned down.
McFarland et al., 2024 changed that. The study explicitly demonstrates three things:
- Identification of a 120 amino acid sweet protein from M. terfezioides
- Confirmation that this specific protein is responsible for the organism’s perceived sweetness
- Heterologous expression in Komagataella phaffii (a type of yeast) yields a protein with an identical amino acid sequence and comparable sensory activity to the native form
Beyond identification, further published research on this protein has demonstrated how it activates the human sweet taste receptor, confirmed by in vitro assays and experimentally validated computational docking models. Additionally, in vitro digestibility and in silico analyses predict a readily digestible protein with no significant similarity to known allergens or toxins.
In plain terms: researchers found the exact protein that makes the honey truffle sweet, proved it was the source of that sweetness, and produced it with the same structure and taste.
This research, discovery, and development have been completed by MycoTechnology, Inc., based in Aurora, Colorado. Since publishing the research, MycoTechnology has successfully scaled production from pilot plant to manufacturing batches, bringing the science from the lab to commercial reality. Honey truffle sweet protein, commercialized as Zukora™ Honey Truffle Sweet Protein, is now available for purchase in the United States. As of March 2026, Zukora™ has achieved self-affirmed GRAS status—substantiated by a comprehensive safety assessment and uncontested independent expert panel evaluation—and a GRAS dossier has been submitted to the U.S. Food & Drug Administration (FDA) for formal review and public transparency.
Closing
We’ve sweetened our food for millennia—from honey to cane sugar to artificial sweeteners—each era bringing a new solution and a new set of compromises. Sweet proteins represent a fundamentally new chapter: not another synthetic molecule, not honey or sugar, but a completely new discovery. Honey truffle sweet protein stands as a compelling example of how disciplined, published science can advance a novel ingredient from curiosity to serious applied research—one careful, evidence-based step at a time.
If you’d like to learn more about Zukora™ Honey Truffle Sweet Protein, head to honeytrufflesweetprotein.com, where you can also request a sample for your next low- or no-sugar formulation.
Sources
Juen, L. et al. (2025). Cryo-EM structure of the human sweet taste receptor T1R2/T1R3. https://doi.org/10.1016/j.cell.2025.04.021
Shi, Z. et al. (2025). Structural and functional characterization of human sweet taste receptor. https://doi.org/10.1038/s41586-025-09302-6
Wintjens, R. et al. (2011). The structural basis of sweetness perception of sweet-tasting plant proteins. https://doi.org/10.1016/j.plantsci.2011.06.009
DuBois, G. E., & Prakash, I. (2012). Non-caloric sweeteners, sweetness modulators, and sweetener enhancers. https://doi.org/10.1146/annurev-food-022811-101236
Leone, S. et al. (2016). Enhancing sweetness and stability of monellin through molecular design. https://doi.org/10.1038/srep34045
Ahmad, M. et al. (2014). Protein expression in Pichia pastoris: recent achievements and perspectives. https://doi.org/10.1007/s00253-014-5732-5
Bilal, M. et al. (2022). Bioprospecting and biotechnological insights into sweet-tasting proteins by microbial hosts. https://doi.org/10.1080/21655979.2022.2061147
McFarland, C. et al. (2024). Discovery, expression, and safety evaluation of a sweet protein from Mattirolomyces terfezioides. https://doi.org/10.1021/acs.jafc.4c04368
Vo, P. et al. (2026). Sweet protein allosteric binding and activation of the human T1R2/T1R3 receptor. https://doi.org/10.1021/acs.biochem.5c00622