This is Edition 02 of the Forward Fooding Novel Ingredients Series, where we go deep on the ingredients we think will define the next decade of food. Edition 01 covered Rubisco.
Why is sugar so hard to replace
Most people understand why we need to eat less sugar. The harder question is why the food industry has not managed to replace it properly.
In the US, the average person consumes 71 grams of added sugar per day, almost three times the American Heart Association’s recommended limit. And this sugar is not only coming from cakes, sweets, or soft drinks. Added sugar is present in 74% of packaged foods sold in supermarkets, hidden under at least 61 different names on ingredient labels: dextrose in the bread, maltose in the pasta sauce, rice syrup in the granola bar.
So the pressure to reduce sugar is real. In a 2025 Tate & Lyle survey of 7,000 consumers across seven markets, more than half said they planned to cut their intake. But buying habits have not changed as much as intentions.
The reason is complex: sugar does much more than make food sweet. It gives biscuits their bite. It helps cakes brown in the oven. It keeps ice cream soft enough to scoop. It gives jam its thick, glossy texture and helps it last longer on the shelf. It feeds the yeast that makes bread rise. It also creates the familiar mouthfeel and pleasure people expect from many foods. That is why replacing sugar is so difficult. A sweetener can copy the sweet taste, but that is only one part of sugar’s job.
The old sugar-reduction toolbox: what already exists?
The food industry has been trying to replace sugar for more than a century. And in one sense, there are already many options. Artificial sweeteners, stevia, monk fruit, and sugar alcohols. Some remove calories almost completely. Some come from plants. Some work well in drinks. Some help rebuild the body and texture that sugar normally provides. But none of them fully replaces sugar.
Artificial sweeteners: powerful sweetness, limited function
Artificial sweeteners (aspartame, saccharin, sucralose, acesulfame-K) were the first big shortcut. They are 200 to 700 times sweeter than sugar, so only tiny amounts are needed. That makes them useful for cutting calories in soft drinks, tabletop sweeteners, and some packaged foods. The problem is that they mainly replace sweetness. Aspartame, for example, breaks down with heat, which makes it unsuitable for many baked products.
However, the deeper problem now is consumer trust. Many consumers remain unsure about artificial sweeteners, even when they are approved for use. In 2023, the WHO recommended against using non-sugar sweeteners for weight control, citing possible long-term health concerns, including increased risk of type 2 diabetes and cardiovascular disease.
Stevia: plant-based, but not sugar-like
Stevia gave the industry a more “natural” story. It comes from the leaves of the Stevia rebaudiana plant and became widely used after high-purity extracts were cleared for use in the US around 2008. It is very sweet, has no calories, and can be described as plant-derived. It holds up under heat, making it usable in baked goods. The catch: at higher concentrations it develops a bitter, liquorice-like aftertaste that consumers notice.
Monk fruit: cleaner taste, limited supply
Monk fruit is another plant-based option, known traditionally as luo han guo. It comes from a vine grown mainly in southern China and contains compounds that taste much sweeter than sugar. In some products, it can taste cleaner than stevia.
The constraint is supply: production is concentrated in a small, growing region in Guangxi province, extraction is costly, and volumes are limited. In practice, it functions mainly as a blending partner, used alongside stevia or erythritol to smooth out aftertastes rather than as a standalone replacement.
Sugar alcohols: useful for bulk, harder on digestion
Sugar alcohols (erythritol, xylitol, sorbitol, maltitol) are carbohydrates found naturally in small amounts in fruits and vegetables. Despite the name, they have nothing to do with drinking alcohol; the word refers to a specific type of chemical bond in their molecular structure. They taste sweet, some almost as sweet as sugar, others about half as sweet, but deliver a fraction of the calories. Moreover, they have a physical advantage. Unlike high-intensity sweeteners, they can replace some of sugar’s volume. A reduced-sugar biscuit made with erythritol, for example, can still hold its shape better than one made only with stevia or sucralose.
But sugar alcohols also have a well-known downside. In larger amounts, they can cause bloating or a laxative effect. This is why many sugar-free sweets carry a warning label. Erythritol has also drawn scrutiny after a 2023 Nature Medicine study linked it to cardiovascular risk, though the FDA found the data did not establish causation.
That is where rare sugars enter the story.
The rise of rare sugars
The existing sugar-reduction toolbox is useful, but incomplete. Most alternatives can replace sweetness, but they struggle to replace everything else sugar does in food. Rare sugars offer a different path.
They are sugars that exist in nature, but only in very small amounts. You can find trace levels in foods like figs, wheat, raisins, and some plants, but not enough to make them useful as everyday ingredients. What makes them interesting is that they are closer to regular sugar than many traditional sweeteners. Some can help with taste, texture, browning, or how a product behaves during cooking.
But the body does not process them in the same way as regular sugar. Because of small differences in their molecular shape, many rare sugars are only partly absorbed or metabolised. In practice, that can mean fewer calories, a lower impact on blood glucose, and a more sugar-like experience than many traditional sweeteners.
Some of the best-known examples in food tech are allulose, tagatose, and trehalose. Each one works a little differently, but they all sit in the same exciting space: they offer sweetness while also helping food companies reduce sugar without completely changing the taste, texture, or cooking performance of a product.
The 1994 Kagawa hinge point
For a long time, rare sugars were more of a scientific curiosity than a practical food ingredient. They existed in nature, but in such tiny amounts that producing them at scale was difficult and expensive.
That started to change in 1994 at Kagawa University in Japan. Dr. Ken Izumori identified an enzyme that could convert fructose, a common sugar, into allulose, one of today’s most discussed rare sugars. An enzyme is a natural tool that helps a specific reaction happen. In this case, it could take fructose and slightly rearrange its shape. That tiny change was a big deal. It meant rare sugars no longer had to be made through complicated chemical processes. They could be produced through a cleaner, simpler, enzyme-based route.
Unpacking rare sugars
Rare sugars are often discussed as one category, but they do not all do the same job.
Allulose, tagatose, and trehalose show three different sides of the rare sugar landscape: one is closest to a sugar replacement, one combines sweetness with a gut-health angle, and one is less about sweetness and more about protecting food during processing.
Allulose
Allulose is found in trace amounts in figs, wheat, and jackfruit. Today, it is usually made by converting fructose with the help of an enzyme. Why it is exciting:
- Tastes like sugar. 70% as sweet, clean flavour, no bitterness, no aftertaste
- Browns and caramelises. Baked goods develop a golden crust. Sauces caramelise. No artificial sweetener, stevia, or sugar alcohol can do this
- It keeps ice cream soft. Ice cream made with it stays scoopable straight from the freezer.
- Very low calorie impact. 0.2–0.4 kcal per gram, versus 4 for sugar.
- Strong US label advantage. Since 2019, the FDA allows products sweetened with allulose to show 0g under “Total Sugars” and “Added Sugars” on the nutrition label. No other sugar has this treatment.
Where it falls short: Allulose is still much more expensive than sugar. It is also less sweet, so it often needs to be blended with other sweeteners. At higher doses, it can cause digestive discomfort. It is also not yet approved for use in the EU.
Market signals: Magic Spoon (United States | $100M+ raised | Series B)
High-protein, zero-added-sugar cereals for adults, using allulose as the core sweetening ingredient. Raised $85M in 2022, now in Walmart, Whole Foods, and Sprouts with 1M+ customers. The clearest proof that allulose can make reduced-sugar work in a category that has resisted good reformulation for decades.
Tagatose
Found naturally in apples, pineapples, and some tropical plant saps, but not in usable quantities. Why it is exciting:
- Tastes almost identical to sugar. 90% as sweet, clean, no aftertaste. Most people cannot tell the difference
- It browns too. Caramelises, provides the same structure and bulk as sugar in baked goods
- Fewer calories. 38% of sugar’s calories. 1,5 kcal per gram.
- Gut-health potential. Much of tagatose reaches the large intestine, where gut bacteria can use it as food. In that process, they can produce compounds such as butyrate, which helps support the gut lining. Think of it less like a sweetener that disappears quickly into the body, and more like one that also interacts with the microbiome.
- Regulatory advantages. Tagatose has an FDA-approved anti-cavity claim, an EFSA-approved low-glycemic claim, and, since April 2026, a US label exemption from “Total Sugars” and “Added Sugars.”
Where it falls short: Historically, it has been expensive to produce. At higher doses, it can cause bloating or digestive discomfort because gut bacteria ferment it. Production is improving, but global scale is still limited.
Market signals: Bonumose (United States | $53M+ raised | Series C)
Bonumose is important because it is trying to solve one of tagatose’s biggest barriers: cost. Their core breakthrough is a production process that makes tagatose from plant starch (corn, wheat, or cassava) rather than whey. Backed by Hershey, ASR Group, and Symrise. Bonumose also played a direct role in the US labelling shift. Its lawsuit against the FDA helped lead to the April 2026 decision exempting tagatose from “Total Sugars” and “Added Sugars.” That gives tagatose a much stronger commercial position in the US market.
Trehalose
Found in mushrooms, honey, and some insects. Unlike allulose and tagatose, trehalose isn’t really a sugar substitute, it’s barely sweet and doesn’t cut calories. Its value is protection: when food is heated, frozen, or dried, trehalose stabilizes proteins and texture so ingredients survive processing and storage intact. It’s a well-established ingredient (FDA GRAS since 2000), used across dried foods, heat-processed meals, and pharmaceuticals. One open question worth watching: a 2018 Nature study suggested a possible link to epidemic C. difficile strains; later work challenged it and regulators haven’t acted, but it remains unresolved.
Market signal: Nagase Viita / Hayashibara (Japan)
Turned trehalose from a curiosity into a global ingredient. Hayashibara industrialized production in 1994, cut costs by over 99%, and built the TREHA® brand now used worldwide.
Precision fermentation: the next front
So far, the rare sugar story has been mostly about enzymes: taking common sugars and rearranging them into less common ones. But another production route is gaining attention: precision fermentation.
What is precision fermentation?
In traditional fermentation, microorganisms like yeast or bacteria transform food. That is how we get bread, beer, yoghurt, vinegar, and many other familiar products.
Precision fermentation uses the same basic principle, but with a more specific instruction. Scientists teach a microorganism to make one target ingredient. Instead of producing alcohol, acid, or bubbles, the microbe produces a specific molecule. This is already used outside food. Most commercial insulin is made this way. So much of the rennet is used in cheese production. Now, the same approach is being applied to sugar reduction.
In sweeteners, precision fermentation opens two main paths:
- Rare sugars are produced via microbial fermentation, instead of using enzymes in a reactor, engineered microbes produce allulose or tagatose directly through their own metabolic processes
- Sweet proteins, a structurally different approach: proteins found in trace amounts in West African fruits that bind to the tongue’s sweetness receptors at extraordinary intensity.
Sweet proteins: nature’s tiny sweetness machines
Some tropical fruits, especially from West Africa, naturally produce proteins that taste sweet. These proteins are not sugars. They are made from amino acids, like any other protein. But when they touch the tongue, they activate the same sweetness receptors that sugar does. Some are hundreds or even thousands of times sweeter than sugar by weight, meaning a tiny amount can deliver a lot of sweetness with almost no calories or blood glucose impact.
The best-known examples are thaumatin, from katemfe fruit; brazzein, from the oubli berry; and monellin, from the serendipity berry.
For a long time, sweet proteins were fascinating but hard to use. The fruits are geographically limited, yields are low, and extracting enough protein from them is not practical at scale. This is where precision fermentation changes the story. Instead of harvesting rare fruits, companies can teach yeast or other microbes to produce the same sweet protein in a fermentation tank. It is similar to brewing, but instead of making beer, the microbe makes a sweetness protein.
Why sweet proteins are not a full sugar replacement
They bring sweetness, but not everything else sugar does. They do not add bulk. They do not help a cake brown. They do not give jam structure, feed yeast, improve shelf life, or create the same mouthfeel. That is why sweet proteins are most useful in blends. They can reduce the amount of sugar needed, while other ingredients help rebuild texture, body, browning, and stability.
Market signals
Oobli (United States | $50M+ raised | Series B)
Oobli uses precision fermentation to produce sweet proteins for food and beverages. Its goal is to recreate sweetness without the calories, blood sugar impact, or agricultural footprint of conventional sugar. Its partnership with Ingredion shows how the category is moving towards combined sweetener systems, rather than one single sugar replacement.
Amai Proteins (Israel | $22M+ raised | Series A)
Uses AI-based protein design and precision fermentation to engineer sweet proteins that improve on nature’s originals, better stability, cleaner taste, and a broader application range. Its sweelin® protein can replace 40–70% of added sugar without changing taste across beverages, dairy, snacks, and chocolate. Has received a US FDA GRAS “no questions” letter supporting US commercialisation.
MycoTechnology (United States | $200M+ raised | Series E)
Colorado-based MycoTechnology brought a sweet protein to market in 2026 with Zukora™ Honey Truffle Sweet Protein, sourced from the Hungarian honey truffle and roughly 2,000 times sweeter than sugar with no calorie impact. It earned self-affirmed GRAS status in December 2025 and is now commercially available in the US, with an FDA GRAS notification expected to clear by year-end. Read our full interview with CEO Jordi Ferre on how MycoTechnology is closing the gap between healthy and delicious with Zukora.
The tensions: why this is still hard to scale
- Cost. Sugar is cheap. That is one of the main reasons it is so hard to replace. Allulose runs $3–8/kg against sucrose at ~$0.50. That 6-16x premium keeps rare sugars in premium products and forces blending rather than full replacement. Production costs are falling, but mass-market parity is not close.
- Scale. The sugar system is enormous. Global sugar production is around ~200 million metric tonnes per year. Rare sugar production is tiny in comparison. Sweet proteins are even earlier, with many still produced at very small volumes.
- Regulation. Allulose is not approved in the EU. Brazzein is not approved in most markets. Tagatose resolved its US labelling problem only in April 2026, after years of legal dispute. A brand building a single global formula around rare sugars hits a hard stop at the EU border.
- Trust and health questions. Most shoppers have never heard of allulose or tagatose, so brands have to explain them carefully, and a bad first experience does real damage, since allulose and tagatose can both cause bloating above ~0.4g per kg of bodyweight per day. Long-term human data is also thin: the trehalose–C. difficile question is unresolved, and the erythritol cardiovascular scare (Witkowski et al., Nature Medicine, 2023), though it doesn’t apply to rare sugars directly, created category-level skepticism.
What this means for the industry, and what has to change
No single molecule is winning. The more realistic path is a sweetener system: allulose for bulk and browning, sweet proteins for intensity, fibres or other ingredients for texture and mouthfeel.
However, three things have to happen for this to scale:
- Costs must fall. Rare sugars are still too expensive for most mass-market products.
- Regulation must align. A formula that works in the US may still be blocked in Europe.
- Consumers need a reason to trust it. Rare sugars are not the same as artificial sweeteners, but that distinction is not yet obvious to most shoppers.
The bottleneck has shifted from science to commercialisation. The molecules exist. The blends are improving. What comes next is making them affordable, approved, trusted, and good enough to make reduced-sugar products worth choosing.
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