Optimization of conditions for galactooligosaccharide synthesis during lactose hydrolysis by β-galactosidase from Kluyveromyces lactis (Lactozym 3000 L HP G)
2007; Elsevier BV; Volume: 107; Issue: 1 Linguagem: Inglês
10.1016/j.foodchem.2007.08.011
ISSN1873-7072
AutoresCristina Martı́nez-Villaluenga, Alejandra Cardelle‐Cobas, Nieves Corzo, Agustı́n Olano, Mar Villamiel,
Tópico(s)Microbial Metabolites in Food Biotechnology
ResumoA study on optimisation of the conditions for galactooligosaccharide (GOS) formation during lactose hydrolysis, produced by Lactozym 3000 L HP G, was carried out. The synthesis was performed during times up to 300 min at 40, 50 and 60 °C, pH 5.5, 6.5 and 7.5, lactose concentration 150, 250 and 350 mg/mL and enzyme concentration 3, 6 and 9 U/mL. The product mixtures were analysed by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). During the hydrolysis of lactose, besides glucose and galactose, galactobiose, allolactose and 6′ galactosyl lactose were also formed as a result of transgalactosylation catalysed by the enzyme. The effect of the reaction conditions was different in the formation of di- and the trisaccharide. Thus, the optimal conditions for galactobiose and allolactose synthesis were 50 °C, pH 6.5, 250 mg/mL of lactose, 3 U/mL of enzyme and 300 min, whereas the best reaction conditions for 6′ galactosyl lactose production were 40 °C, pH 7.5, 250 mg/mL of lactose, 3 U/mL of enzyme and 120 min. These results show the possibility to obtain reaction mixtures with Lactozym 3000 L HP G, with different composition, depending on the assayed conditions.
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