The beta-fructofuranosidase from the yeast Xanthophyllomyces dendrorhous (Xd-INV) catalyzes the synthesis of neo-fructooligosaccharides (neo-FOS of the (6)G-series), which contain a beta(2 -> 6) linkage between a fructose and the glucosyl moiety of sucrose. In this work we demonstrate that the enzyme is also able to fructosylate other carbohydrates that contain glucose, in particular disaccharides (maltose, isomaltulose, isomaltose, trehalose) and higher oligosaccharides (maltotriose, raffinose, maltotetraose), but not monosaccharides (glucose, fructose, galactose). With maltose as acceptor, the reaction in the presence of Xd-INV proceeded with high regioselectivity; the product was purified and chemically characterized, and turned out to be 6'-O-beta-fructosylmaltose (neo-erlose). Using 100 g/L sucrose as fructosyl donor and 300 g/L maltose as acceptor, the maximum concentration of neo-erlose was 38.3 g/L. Thus, novel heterofructooligosaccharides with potential applications in the functional food and pharmaceutical industries can be obtained with Xd-INV. (C) 2014 Elsevier Ltd. All rights reserved.