Production of tagatose and talose through isomerization of galactose in a buffer solution under subcritical water conditions

Galactose was isomerized in pure water or in 10 mmol/L sodium phosphate buffer at 160 °C under pressurized conditions. The isomerization of galactose to tagatose and talose in phosphate buffer resulted in 14% and 1.4% yields, respectively, which were significantly higher than those obtained in subcritical pure water (0.6% and 6.3. Our results indicate that the galactose isomerization by Lobry de Bruyn-Alberda-van Ekenstein transformation rarely occurred at low pH due to the formation of organic acids