Effect of Various Conditions on the Formation of Oligosaccharides in Milk Treated with β-Galactosidase

Abstract

Fresh pasteurized milk was inoculated with β-galactosidase from two different microbial sources at three levels and analyzed for oligosaccharides by high performance liquid chromatography. Five oligosaccharides were observed in the course of hydrolysis. However, only two of these showed measurable increases in concentration. Rate of oligosaccharide formation during hydrolysis was influenced by source and amount of enzymes, reaction time, and temperature. Maximum concentrations of the two oligosaccharides occurred between .5 and 3 d at 7°C and between 1 and 3 d at 1°C, depending on the level of the enzyme used. The higher level of enzyme formed a higher concentration of oligosaccharides than the low level, except at 37°C. After maximum concentration was reached, the two oligosaccharides decreased following hydrolysis, but rate of decrease was dependent upon time, temperature, and enzyme concentration. Hydrolysis of the oligosaccharide was faster at 7°C and at the higher enzyme concentration. Maximum concentration of oligosaccharides was .374 g/100 g milk but was negligible after 7 d, except when the low level of enzyme was used. The total concentration of the oligosaccharides formed in enzyme-treated milk was insignificant. © 1986, American Dairy Science Association. All rights reserved.