Production of High-Content Galactooligosaccharides by β-Galactosidase Catalysis and Yeast Fermentation

• Main Authors: Wei-Lun Tai, 戴偉倫
• Other Authors: Dey-chyi Sheu
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/34943560561286717013

碩士 === 大同大學 === 生物工程學系(所) === 93 === Galactooligosaccharides (GOS) have been received increasing interest, because they can promote the proliferation of bifidobacteria and lactic acid bacteria in the human intestine and thus enhance the human health. GOS is the collective name of oligosaccharides constructed by 2-5 glycosyl moieties, mainly galactoside. Commercial GOS are produced from lactose by the transgalactosyl catalytic activity of β-galactosidase. Because of the enzymatic behavior, commercial GOS consisted of large amount of glucose and lactose. Such product not only was a low-content GOS, but also was not available for the lactose-intolerant people. The present study engaged in the enhancement in GOS yield by a mixed-enzyme system and the increase in GOS content by the yeast fermentation. Among the β-galactosidases from Kluyveromyces lactics, Aspergillus oryzae and Huang-Tai Company, the enzyme from Huang-Tai Company resulted in the highest concentration and yield of GOS. In the mixed-enzyme system, in which β-galactosidase and glucose oxidase were used, the glucose byproduct was converted into calcium gluconate precipitate and the GOS yield was increased from 25% to 28%. During the fermentation of low-content GOS by Kluyveromyces marxianus, the digestible sugars including glucose and lactose were depleted and the GOS content was increased from 25% to 96%, on a dry weight basis.