Utilization of cellobiose 2-epimerases for epilactose production in milk

Abstract

I was reported recently that enzymes belonging to the emerging class of cellobiose 2-epimerases (CE) from various aerobic microorganisms converted lactose into epilactose in defined buffer systems. Lactose (4-O-β-D-galactopyranosyl-D-glucose) is a main component of cow milk, with an average content of about 4.5 % (w/v). Apart from this main sugar also traces of lactulose (4-O-β-D-galactosyl-D-fructose) and epilactose (4-O-β-D-galactosyl-D-mannose) can be found in UHT treated milk. These sugars are formed by isomerisation and epimerization during the heating process. Both lactulose and epilactose seem to possess prebiotic properties. Therefore, enzymatic in situ production of these sugars may introduce an added value for dairy products. We showed that CE from two mesophilic microorganisms, Flavobacterium johnsoniae DSM 2064 and Pedobacter heparinus DSM 2366, were capable of converting lactose into prebiotic epilactose in a complex milk system.