Researchers from Tufts University, US, have developed a process that may unlock the commercial potential of tagatose, a low-calorie, low-glycemic sugar. By using bacteria as tiny bioreactors that encapsulate the enzymes and reactants, the scientists were able to increase yields from 30 to 85 percent, which they say could lead to large-scale manufacturing and getting tagatose on every supermarket shelf. The US Food and Drug Administration (FDA)-approved natural sugar has only 38 percent of the calories of traditional table sugar, is safe for diabetics and does not cause cavities, meaning it could be a key tool in reformulation targets.

“Although other commercial syntheses of tagatose are available, they result in a supply priced at about US$35 per pound, which is very expensive. It is hoped that this method of synthesis could bring that price down significantly, making it more widely available,” Mike Silver, Associate Director of Public Relations at Tufts, tells.

While tagatose is derived from fruits and dairy products, it is not abundant and can be difficult to extract. The current manufacturing process involves a conversion from more easily obtained galactose to tagatose and is highly inefficient.

Thanks to its good browning ability, tagatose is very suitable for baking purposes, where a caramelized flavor is desirable. Additionally, Silver hopes that its natural taste could give it an edge over artificial sweeteners. “It only slightly raises the level of glucose in the blood after ingesting, with a glycemic index of 3, in comparison to 99 for conventional sugar.”

However, the method has not yet been developed to commercial scale, and the scientists have not pursued a patent for their system. “There is always room to improve processes. Although this is the most productive system compared to other published studies, it is still quite slow, so we can improve rates and productivity. Higher conversions – up to 100 percent – would be even more desirable,” says Nikhil U. Nair, Assistant Professor in Chemical & Biological Engineering at Tufts and who partook in devising the system.