News – full story
Xylitol has 40% fewer calories than white sugar
24/10/2012
New one-pot process for xylitol production
Uses milder conditions and increases yield
Helen Tunnicliffe
CHEMISTS at Singapore’s A*STAR Institute of Bioengineering and Nanotechnology have developed a new one-pot method to produce xylitol, an increasingly popular plant-based artificial sweetener.
At present, xylitol is made from hemicellulose in a multiple-stage process at high temperatures and pressures in the presence of hydrogen. Guangshun Yi and Yugen Zhang say that although their method uses isopropanol as a hydrogen source, which risks a more negative environmental impact than using just hydrogen itself, the new process is more environmentally friendly as it involves only one stage and the reaction conditions are much milder.
The conditions inside the reactor are highly acidic, which serves to break down some of the bonds in the hemicellulose from plant matter into an intermediate molecule, xylose. The reaction hinges on a reusable ruthenium catalyst, which in the presence of the isopropanol – the source of hydrogen – converts xylose into xylitol. The reaction occurs at a temperature of 140°C.
The optimum reaction time is around 3 hours, which is relatively short, and the researchers say they can achieve a yield of 80%.
“We are currently in discussion with a company to develop this technology, and are also in the process of testing and optimising conditions for real industrial samples,” says Zhang.
ChemSusChem DOI: 10.1002/cssc.201200290
