Dextransucrase is the biocatalyst for dextran synthesis and other products of commercial interest such as fructose and panose from sucrose and maltose. When an acceptor is used (besides sucrose as substrate), some of the glycosyl units are deviated from dextran synthesis and acceptor products are formed. When maltose is the acceptor the prime product is a trisaccharide, panose, composed by one maltose unit and one glucose unit linked by an alpha-1,6-glycosidic bond. In this work, a mechanism accounting for maltose in the reactor as well its its prime acceptor product (panose) is considered to model an ideal continuous stirred tank reactor (ICSTR). The concepts of factorial design were used to simulate the model and surface response graphs were used to analyze the effect of feed flow rate, enzyme, sucrose and maltose concentration on panose and higher oligosaccharide formation. (c) 2005 Elsevier Ltd. All rights reserved.