Abstract:The rare monosaccharide D-allulose is a C-3 epimer of D-fructose, which is mainly produced through the isomerization of D-fructose by D-tagatose 3-epimerases (DTEases) or D-allulose 3-epimerases (DAEases). D-Allulose can not only be used as a food ingredient and dietary supplement, but also exhibits a variety of physiological functions and health benefits such as insulin resistance improvement, antioxidant enhancement and hypoglycemic controls. Therefore, D-allulose is of great value in development and research as a healthy alternative for conventional high-energy sugars such as sucrose and fructose. This review provides a systematic analysis of physicochemical property, existing sources, metabolism in vivo, physiological functions, applications and recent processing technologies of D-allulose. The existing problems and proposed solutions in the production of D-allulose are discussed. A green and recyclable process technology for D-allulose production is also proposed for low waste generation, low energy consumption and high conversion.
