Trehalulose is a disaccharide made up of a molecule of fructose bound to a molecule of glucose. Like isomaltulose, it is a structural isomer of sucrose that is present in small quantities in honey. It makes up 50% of sugars in the honeydew of silverleaf whiteflies and is synthesised from sucrose by some bacteria, such as Protaminombacter rubrum. Because the anomeric carbon of the fructose moiety is not involved in the glycosidic bond, it is a reducing sugar.

Because the fructose and glucose molecules are linked by a 1,1 glycosidic bond, which is more stable than the 1,2 glycosidic bond in sucrose, it is broken down more slowly than sucrose in the small intestine, giving it a lower glycemic index. This more stable bond also means that it cannot be utilised by Streptococcus mutans, and it is therefore non-cariogenic.

Unlike isomaltulose, trehalulose strongly resists crystallisation, and forms an amorphous solid when dried. Its sweetness relative to sucrose has been estimated as between 0.4 and 0.7.

Honey from Stingless Bees

These Stingless bees make medicinal honey. Some call it a miracle liquid. Stingless bees, also known as meliponine bees, surround a honey pot within their hives. Their honey is used to help wounds heal and to treat infections—and brings economic relief to keepers in the Mayan zones.

There is a long and rich history of using honeys as medicine, especially in ancient times. Some records show that people have used honey as a balm, an inebriant, a psychoactive substance, or as a poison. Multiple contemporary studies suggest that honeys from honeybees and stingless bees have antimicrobial, anti-inflammatory, and wound-healing properties.

Stingless bee honey, a novel source of trehalulosestingless

Stingless bee (Meliponini) honey has long been considered a high-value functional food, but the perceived therapeutic value has lacked attribution to specific bioactive components. 

Trehalulose is a naturally occurring isomer of sucrose, but has a much slower rate of release of monosaccharides into the bloodstream than sucrose. This disaccharide is therefore highly beneficial in having both a low insulinemic index and low glycemic index. Trehalulose is also known to be acariogenic, and a highly active antioxidant, and these properties may in no small way contribute to the reported beneficial health properties of stingless bee honey.

This novel natural occurrence of trehalulose in a food commodity is of particular interest in the food industry, due to reported health benefits associated with this disaccharide related to antidiabetic and acariogenic activity and low glycemic index. The presence of this disaccharide as a major component in stingless bee honey is then a likely contributor to previous observations of similar biological activity attributed to these honeys. Studies have, for example, described the antidiabetic properties of Geniotrigona thoracica stingless bee honey, including protection against rises in fasting blood glucose levels and antioxidant properties.

Stingless bee honey has been shown to exhibit higher inhibition in in vitro α-amylase and α-glucosidase enzyme inhibition assays. All such properties are consistent with the high level of trehalulose, rather than the previously attributed maltose, in honey from these species. Maltose has similarly been reported as a major disaccharide in honey from other stingless bee species not examined in the study, and it would seem likely that these reports may also reflect further misidentification of trehalulose and warrant further investigation.

The long-established consumption of stingless bee honey as a therapeutic/medicinal commodity is consistent with the reported bioactivity of trehalulose as a natural sucrose isomer. Trehalulose like isomaltulose shows a reduced rate of hydrolysis in the small intestine (about one third that of sucrose) with application in controlling blood sugar levels for diabetes, glucose intolerance and obesity prevention.

Trehalulose is 70% as sweet as sucrose and extremely water-soluble and, while not readily crystallized, has found commercial application in jellies, jams, cereal bars, juices etc. Our identification of trehalulose as a major component in stingless bee honeys then provides a new, abundant and novel source for this bioactive disaccharide and opens the way to investigate the use of stingless bee honey as a food ingredient to achieve the same health benefits as attributed to pure trehalulose.