The formation of galacto-oligosaccharides (GOS) in milk during the treatment with several commercial β-galactosidases (Bacillus circulans, Kluyveromyces lactis and Aspergillus oryzae) was analyzed. Using K. lactis beta-galactosidase, a treated milk with 7.0 g/L GOS −the human milk oligosaccharides (HMOs) concentration is between 5 and 15 g/L−, and with a low content of residual lactose (2.1 g/L, compared with 44-46 g/L in the initial milk sample) was obtained.
Reference: B. Rodriguez-Colinas, L. Fernandez-Arrojo, A.O. Ballesteros, F.J. Plou. Galactooligosaccharides formation during enzymatic hydrolysis of lactose: towards a prebiotic enriched milk. Food Chemistry (2013). doi: 10.1016/j.foodchem.2013.08.060