Galactooligosaccharides as Prebiotics and Their Production from Lactose

Abstract

In recent years an increasing interest in functional foods has been observed. Prebiotic oligosaccharides are one of the recognized ingredients. This group of compounds includes, e.g., fructooligosaccharides, inulin, isomaltooligosaccharides, lactose derivatives such as lactitol, lactulose, lactobionic acid or galactooligosaccharides. Prebiotic oligosaccharides enhance the growth of bifidobacteria and lactobacilli in the intestine, which are considered to be beneficial to human health. Galactooligosaccharides are produced in the lactose hydrolysis using lactase (Β-galactosidase, EC 3.2.1.23) preparations since lactase shows also transferase activity. Lactose accounts for over 70 % of the solid content in the milk whey obtained in cheese production. Production of galactooligosaccharides from lactose could be a method of whey utilization. Due to a rapidly increasing production and use, the conditions for achieving their maximal yields have been tested (lactose concentration and source, pH, temperature, enzyme concentration and source, enzyme immobilization). Galactooligosaccharides are used in beverages, powdered milk for infants, confectionery, bakery products, yoghurts and dairy desserts.