Multienzymatic production of sweeteners from lactose

The dairy industry produces significant volumes of lactose-rich waste every year. This has prompted intensive research in the development of new processes for the synthesis of added-value products like sweeteners and prebiotics. The advances achieved in enzyme stabilization, among which immobilization stands out, have allowed ever more innovative enzyme applications. Noteworthy are the multienzymatic systems in which two or more enzymes either free, immobilized, or coimmobilized are used in a single reactor, the denominated one-pot system. In this direction, the multienzymatic production of sweeteners from lactose has gained increased attention. Two examples are the production of fructose and tagatose syrups. To obtain these products, enzymes like β-galactosidase, glucose isomerase, and L-arabinose isomerase are required. Furthermore, it has been reported that one-pot systems offer interesting operational advantages for the production of these sweeteners. This chapter outlines the current status and prospects of the valorization of lactose by the enzymatic synthesis of sweetening syrups.