Levansucrases: a review of their catalytic properties, product characterization and applications in food systems

Owing to the promising physiological effects of levan and levan-type fructooligosaccharides, levansucrase (LS, EC 2.4.1.10) has garnered much interest in recent years for pharmaceutical, cosmetic, and food applications. LS is a fructosyl-transferase that catalyzes the synthesis of complex oligosaccharides by acquiring a fructosyl residue from a donor molecule and performing non-Leloir transfer to an acceptor molecule. The mechanism of action of LS toward various carbohydrates has been well documented, and increasing interest has been drawn to the ability of alkyl and phenolic compounds to act as acceptor substrates for LS-catalyzed transfructosylation reactions. Many studies have also focused on improving the production of LSs and their product spectrum, whether by increasing their overall activity or shifting their selectivity toward a particular reaction. With these advances, the possibility of applying LS to food processing has gradually gained momentum. This review provides a comprehensive discussion of the catalytic properties of LS and full characterization of its reaction products. We then discuss some applications of microbial LS for the biogeneration of functional ingredients in food systems.