TY - JOUR
T1 - Raw galacto-oligosaccharide purification by consecutive lactose hydrolysis and selective bioconversion
AU - Santibáñez, Luciana
AU - Guerrero, Cecilia
AU - Illanes, Andrés
N1 - Funding Information:
To Dr. Flávia Passos from the Department of Food Technology, Federal University of Viçosa (Brasil) for supplying Kluyveromyces lactis strain CCT 7735. To Dr. Francisco Plou from the Institute of Catalysis and Petroleum Chemistry, CSIC, Madrid, Spain for his assistance in enzyme immobilisation and analysis. This work was funded by Fondecyt (Chile) (Grant 1130059 ) and CONICYT (Chile) (CONICYT-PCHA/Doctorado Nacional/ 2013-211305 ).
Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2017/12
Y1 - 2017/12
N2 - Galacto-oligosaccharide (GOS) yields obtained by enzymatic transgalactosylation with β-galactosidases are rather low, so purification of the raw GOS is a major issue. In the quest for improving GOS purification, an additional step of lactose hydrolysis is proposed, using immobilised β-galactosidase and permeabilised cells expressing β-galactosidase activity as biocatalysts. To select the best operational conditions for lactose hydrolysis in raw GOS employing both biocatalysts different enzyme:substrate (lactose) mass ratios were evaluated. Bioconversion of the lactose-hydrolysed raw GOS obtained with the two biocatalyst forms were compared, and biocatalyst reuse was evaluated. Lactose hydrolysis of raw GOS allowed the removal of around 70% of the lactose content and increased the relative GOS content by 20%. Incorporation of the lactose hydrolysis step led to a purity and recovery of GOS of 96–97% and 92–96%, respectively, depending on the biocatalyst used.
AB - Galacto-oligosaccharide (GOS) yields obtained by enzymatic transgalactosylation with β-galactosidases are rather low, so purification of the raw GOS is a major issue. In the quest for improving GOS purification, an additional step of lactose hydrolysis is proposed, using immobilised β-galactosidase and permeabilised cells expressing β-galactosidase activity as biocatalysts. To select the best operational conditions for lactose hydrolysis in raw GOS employing both biocatalysts different enzyme:substrate (lactose) mass ratios were evaluated. Bioconversion of the lactose-hydrolysed raw GOS obtained with the two biocatalyst forms were compared, and biocatalyst reuse was evaluated. Lactose hydrolysis of raw GOS allowed the removal of around 70% of the lactose content and increased the relative GOS content by 20%. Incorporation of the lactose hydrolysis step led to a purity and recovery of GOS of 96–97% and 92–96%, respectively, depending on the biocatalyst used.
UR - http://www.scopus.com/inward/record.url?scp=85028448537&partnerID=8YFLogxK
U2 - 10.1016/j.idairyj.2017.07.008
DO - 10.1016/j.idairyj.2017.07.008
M3 - Article
AN - SCOPUS:85028448537
VL - 75
SP - 91
EP - 100
JO - International Dairy Journal
JF - International Dairy Journal
SN - 0958-6946
ER -