Ultrasound-assisted enzymatic synthesis of galacto-oligosaccharides using native whey with two commercial β-galactosidases: Aspergillus oryzae and Kluyveromyces var lactis.

Native whey obtained during casein micelle microfiltration was used as a novel source to produce galacto-oligosaccharides (GOS). Since the presence of macromolecules and other interferers reduces biocatalyst performance, this work evaluated the effect of different ultrasound processing conditions on GOS synthesis using concentrated native whey. Ultrasonic intensities (UI) below 11 W/cm tended to increase the activity in the enzyme from Aspergillus oryzae for several minutes but accelerated the inactivation in that from Kluyveromyces lactis.