ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Influence of reaction medium composition on enzymatic synthesis of galactooligosaccharides and lactulose from lactose concentrates prepared from whey permeate

Marek Adamczak, Danuta Charubin, and Włlodzimierz Bednarski

Department of Food Biotechnology, University of Warmia and Mazury, Olsztyn J. Heweliusz St. 1, 10-718 Olsztyn, Poland

E-mail: marek.adamczak@uwm.edu.pl

Received: 26 June 2008  Revised: 6 October 2008  Accepted: 7 October 2008

Abstract: The paper presents the results of investigations into the technological possibilities of controlling the transgalactosylation process of lactose in permeate after whey ultrafiltration in order to improve the efficiency of galactooligosaccharides or lactulose synthesis. The synthesis efficiency was influenced by the selection of a β-galactosidase preparation, substrate concentration and, in the synthesis of lactulose, also by the ratio of lactose and fructose added to the reaction mixture. The obtained synthesis efficiency of GOS and, most of all, of lactulose (65 g L⁻¹), may be found satisfactory. The study also resulted in a proposed GOS or lactulose concentrates (concentrated or dried) production technology using permeate after ultrafiltration of milk or whey as lactose sources.

Keywords: β-d-galactosidase - whey-permeate - galactooligosaccharides - lactulose - transgalactosylation

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-009-0010-1

Chemical Papers 63 (2) 111–116 (2009)