Preparation of organic galactooligosaccharide from organic lactose

In this study, we developed a novel organic galactooligosaccharide (GOS) by using β-galactosidase from organic lactose to perform transgalactosylation, and the quality of the novel organic GOS was compared to that of commercial GOS. A new β-galactosidase isolated from Bacillus species converted 80% of lactose composed of galactose and glucose into a transgalactosylation product containing a β-1,6 bond form of glucose and galactose. In addition, β-galactosidase was found to induce conversion of organic lactose to GOS (total GOS conversion of 60.50%) more efficiently than other commercially available enzymes (Lactozym, Maxilact, and Pectinex). The conversion yield of GOS from organic lactose was significantly higher in the β-galactosidase usage group (53.3∼63.3%) than in the Lactozym usage group (39.5∼50.6%). Compared with other commercial GOS products (54.03∼60.27%), total GOS content of organic GOS (60.50%) manufactured under optimal conditions was high. The result, which was confirmed by analysis of lactose contents, suggests that organic GOS in this study was shown to be a novel organic GOS with high quality and the quality of organic GOS is very suitable as a raw material for GOS production. Consequently, organic GOS prepared from the current study is likely to have potential as an industrial product containing high GOS content.