As we pay more attention to what’s in their food, sugar has become one of the most debated ingredients on the label. Many of us want to cut back – not because we want to give up sweetness, but because we want to feel better about what we’re consuming. Yet anyone who has tried to replace sugar knows the familiar trade-off: a sweetener that technically works, but comes with an artificial taste, an odd after-feel, or digestive discomfort that takes away from the enjoyment of the food itself.
Despite the wide range of sugar substitutes available today, there remains a noticeable gap between what consumers expect and what these alternatives actually deliver. We are looking for sweetness that tastes natural, feels comfortable to consume, and fits into a healthier, lower-calorie lifestyle, without compromises. This gap is where sweet proteins come into focus.
Sweet proteins are naturally occurring proteins found mostly in certain fruits native to West Africa. To date, there are eight known sweet proteins. These proteins, which have the potential to be used as low-calorie substitutes of sugar in a variety of food applications, are less likely to cause the side effects associated with artificial sweeteners, as they are digested just like any other protein. At the same time, their intense sweetness means they can be used at very low levels, offering a promising low-calorie alternative to sugar. However, in their natural form, sweet proteins are rare, can be unstable, and are not suitable for large-scale food production.
To unlock their full potential, scientists turn to modern computational protein design and biotechnology. By carefully optimizing the protein’s structure and producing it through controlled fermentation processes, already commonly used by food industry, it becomes possible to improve stability, ensure consistent quality, and manufacture sweet proteins at scale. This approach allows the benefits of naturally sweet proteins to be delivered reliably, sustainably, and safely – bringing a promising scientific discovery closer to actual food applications. But with any new food technology, an important question follows: how do we make sure it’s safe to eat?
What does ‘safe to eat’ actually mean?
When we say a food ingredient is “safe,” we simply mean that it can be eaten without causing harm at a defined intake level (dosage per kg body weight), even when consumed regularly. For new ingredients like sweet proteins, safety isn’t something we assume; it’s something we must prove by established data. Regulators such as the FDA look at how the body handles the ingredient: how it’s digested, whether it could trigger allergies, and whether it has any unwanted biological effects. They also verify that the final product is free from unintended or harmful contaminants. Think of it like introducing a new guest to your home; before you invite them in, you want to know who they are, how they behave, especially in uncomfortable situations, and whether they get along with everyone else. In the same way, a new sweetener must show, through data and testing, that it behaves just like familiar food proteins and fits safely into a standard human diet.
In the United States, this evaluation is often carried out through the Generally Recognized as Safe (GRAS) process. As part of this process, a company submits all relevant safety data for independent expert review and for evaluation by the U.S. Food and Drug Administration. When the FDA completes its review and issues a “no questions” letter, it means the agency has no further safety concerns based on the evidence provided. In other words, after reviewing how the ingredient is made, how it behaves in the body, and how it is intended to be used, the FDA agrees that the ingredient meets the standard for safe use in food.
In February 2026, sweelin®, Amai Proteins’ novel sweet protein, reached this exciting milestone. Following review of its GRAS notice, the FDA issued a “no questions” letter, enabling sweelin® to be marketed as a general sweetener in the United States for its intended use levels.
The Journey to Proving Safety
Like any novel food or ingredient, proving safety is a rigorous scientific and regulatory journey, which Amai Proteins and others have undertaken. Just as new medicines must be tested before being prescribed, new food ingredients must go through a careful safety evaluation before they reach your plate.
Before a new sweet protein can be approved for public use, companies must present a comprehensive package of evidence to regulatory authorities.
This package covers the full story of the ingredient: what the protein is and how it is structured, how it is produced and purified, how the body digests it, and whether it poses any toxicological or allergenic risks. Regulators also require confirmation that the final protein powder is free from contaminants such as heavy metals or pathogens, as well as clear information on how the ingredient will be used, at what levels, and how much consumers are expected to ingest.
Let’s walk through the main steps that are typically needed to approve a novel protein.
1. Identity
Regulators first need to know exactly what the molecule is and how it’s made. That means a characterization of the protein (including the amino acid sequence and 3D structure), as well as description of how the sweet protein is identified, manufactured and packed. This level of detail ensures that the ingredient is well defined and consistently made.
For example in the alternative-protein industry, many ingredients including sweet proteins, dairy proteins, and even components used in cultivated meat, are made using precision fermentation. In this process, carefully designed microorganisms are used to make the target protein in clean, controlled environments, similar to how fermentation has long been used to produce foods like beer or wine. Regulators look closely at the fermentation steps to validate the microbial strain that are used, and that the production steps are well-defined and tightly controlled.
2. How the Body Handles It – Digestibility and Allergenicity
This includes two things: how the body digests the protein and whether it might trigger allergies. Digestibility tests check that the protein breaks down normally during digestion and doesn’t create any harmful by-products along the way. Sweet proteins generally follow the same path as common dietary proteins: the digestive system breaks them down into simple amino acids. Allergenicity assessments, on the other hand, compare the protein’s building blocks (its peptides) to those of known allergens. If a match is found, it must be clearly labelled on the final product. For instance, when companies produce milk proteins like beta-lactoglobulin through fermentation, the protein is still considered a milk allergen for people with dairy allergies, and must be labelled as such.
3. Toxicology and Safety Studies
Even after understanding how a sweet protein is digested and whether it could cause allergies, the regulatory authorities still require one more layer of reassurance: toxicology tests. These studies are internationally standardized test studies, accepted by regulators, designed to confirm that the ingredient does not affect the genetic material (DNA and chromosomes) and has no harmful effects on the body, even when consumed at levels far higher than what people would ever eat in real life. Researchers look for any signs of toxicity – for example, changes in body weight, organ function, or overall health. For sweet proteins, results are typically reassuring. Since they are broken digested and down into amino acids like any protein in our diet, toxicology tests consistently show no adverse effects. Amai’s sweet protein sweelin®, for instance, underwent a full safety evaluation confirming that the ingredient is well tolerated and safe at all tested levels. These findings help build the scientific foundation needed for regulatory approval and consumer trust.
4. Exposure and Consumption Estimates
Once safety and digestibility are established, the next step is to estimate how much of the sweet protein people are likely to consume in everyday life. The idea is to look at the types of foods the ingredient will be used in, how often people typically eat those foods, and how much of the protein each serving contains. These estimates help confirm that even the highest possible intake levels of a consumer (for example, someone who eats a lot of sweetened products) would still be well within defined safe use levels. This step ensures that the ingredient remains safe not only in theory, but for every-day use.
Looking Ahead — The Future of Safe Sweetness
Sweet proteins are paving the way for a new era of sweetness – one that delivers great taste while supporting healthier diets and sustainable food system. As research and regulations advance, these innovative ingredients are moving closer to everyday use. Each new protein that undergoes safety evaluation build greater confidence in their ability to reduce reliance on traditional sugars and artificial sweeteners. The science behind sweetness is rapidly evolving, and safety is the foundation that allows these breakthroughs to become part of our daily lives.
