A rare health sugar, trehalulose, discovered in stingless bee honey

Abstract

Stingless bee honey has long been prized for its flavour and health benefits in Australia. We discovered a rare health sugar, trehalulose, as the major sugar component (13-44%) in stingless bee honey samples from Australia, Malaysia and Brazil by liquid chromatography-mass spectrometry (LCMS) and nuclear magnetic resonance (NMR). Trehalulose is a naturally occurring isomer of sucrose with a much slower releasing rate of monosaccharides into human bloodstream. It is known to be an acariogenic and antioxidant sweetener. This study is the first identification of trehalulose as a major component within food commodity and facilitates trehalulose as the bioactive marker for stingless bee honey authentication. The natural presence of trehalulose in stingless bee honey is highly curious. We further investigated the origin of trehalulose and gained insight into optimization of its level in stingless bee honey. By feeding sucrose solutions to confined stingless bees, the complete conversion to trehalulose (64-72%), erlose (18-23%), fructose (9-12%) and minor glucose was observed. In contrast, feeding 1:1 glucose/fructose solutions to stingless bees resulted in no conversion to trehalulose. Therefore, stingless bees are able to produce trehalulose from the isomeric disaccharide sucrose, not directly from the monosaccharide components, glucose and fructose. Hence, stingless bees with natural access to floral nectar rich in sucrose will produce honey high in trehalulose.