Brazilian Journal of Food Technology
versão On-line ISSN 1981-6723
LISBOA, Cristiane Reinaldo; COSTA, Fátima Aparecida de Almeida; BURKERT, Janaína Fernandes de Medeiros e BURKERT, Carlos André Veiga. Synthesis of galactooligosaccharides from lactose using commercial β-galactosidase from Kluyveromyces lactis. Braz. J. Food Technol. [online]. 2012, vol.15, n.1, pp. 30-40. ISSN 1981-6723. http://dx.doi.org/10.1590/S1981-67232012000100004.
The main goal of this work was to study the influence of the reaction parameters on the enzymatic production of galactooligosaccharides (GOS) using the commercial β-galactosidase from Kluyveromyces lactis (Lactozym® 3000 L) and lactose as the substrate. A 23 experimental design was proposed, verifying the influence of the temperature (30 to 40 °C), lactose concentration (200 to 400 mg.mL-1) and enzyme concentration (5 to 10 U.mL-1) on the performance of the enzymatic reaction. The assays were carried out at 180 rpm and pH 7.0 (0.1 M sodium phosphate buffer). The enzyme Lactozym® 3000 L presented transgalactosylation activity, reaching a yield of 41.9% and GOS concentration of 167.5 mg.mL-1 in a reaction system composed of 400 mg.mL-1 of lactose and 5 U.mL-1 of enzyme at 30 °C and 14 h of reaction. Under these conditions the lactose conversion was 65.0%. Higher lactose concentrations favored the transgalactosylation mechanism, whereas the hydrolytic mechanism dominated with lower concentrations.
Palavras-chave : Prebiotics; Oligosaccharides; Transgalactosylation.