Production and bioactivity of oligosaccharides derived from lactose

In an attempt to offer a broad overview on lactose applications as a source of bioactive carbohydrates, in this chapter, the authors have collected the most recent investigations on methods to produce these compounds, which have a positive effect on gut microbiota. Chemical and biological productions of tagatose, lactulose, lactosucrose, lactulosucrose, and galactooligosaccharides, among others, have been described. Moreover, their main uses, based on their bioactivity and techno-functional properties, are also shown together with a brief description of purification methods of the mixtures obtained. Particular attention has been paid to a new generation of oligosaccharides derived from lactulose with a potential prebiotic effect, which is even better than that of this recognised functional ingredient. These novel oligosaccharides, mainly composed of 6′-galactosyl lactulose and 1-galactosyl lactulose, can be obtained with good yields either by transgalactosylation of lactulose or by chemical isomerisation under basic media of galactooligosaccharides—the latter constitutes a good and economic option.This work has been financed by projects AGL2011–27884 from MICINN, R + D program of the Comunidad de Madrid, project ALIBIRD-CM-P 2009/AGR-1469 and POII10–0178–4685 from Junta de Comunidades de Castilla-La Mancha and European regional development fund (ERDF)Peer Reviewe