Scientists develop X3—a zero-calorie protein sweetener 10,000 times sweeter than sugar

Scientists are working on a new sugar substitute made from sweet-tasting proteins. The project, called NovelSweets, aims to create a calorie-free alternative that could help reduce sugar consumption. One of the key developments is a protein variant named X3, which is far sweeter than ordinary sugar but contains no calories. The World Health Organization advises limiting daily sugar intake to 25 grams per person. Yet a single 250-millilitre glass of cola already contains 27 grams, exceeding this recommendation. High sugar consumption has been linked to health problems such as tooth decay, high blood pressure, and chronic diseases.

Researchers at the Fraunhofer Institute for Molecular Biology and Applied Ecology are developing protein-based sweeteners as a healthier alternative. One focus is on brazzein, a protein extracted from the African plant *Pentadiplandra brazzeana*. The team has optimised this protein for better stability under different temperatures and pH levels, while also increasing its sweetness. The enhanced version, named X3, is produced through microbial fermentation. It is roughly 10,000 times sweeter than household sugar but has no effect on blood sugar levels. Early tests suggest it has a honey-like flavour. Project partner metaX is now developing the first X3-containing products, including a low-protein, cocoa-based drink powder. Before X3 can reach the market, further steps are needed. The manufacturing process must be refined, and additional validation tests must be completed to ensure safety and quality.

If approved, X3 could offer a powerful, calorie-free alternative to sugar. The protein-based sweetener may help reduce the health risks linked to excessive sugar intake. Developers are now working on final tests and product formulations before commercial release.