GLUCOSE ISOMERASE ACTION ON ACID WHEY LACTOSE HYDROLYSATE AND OTHER SUGARS.
AdvisorStull, J. W.
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PublisherThe University of Arizona.
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AbstractIn this work, glucose isomerase (GI) activity was measured with several sugar substrates. Lactase was also used with several carbohydrate substrates to observe its hydrolytic action. In order to observe the enzymes' action, a small batch reactor was designed and used in the entire project. Paper partition chromatography, was the analytical method of choice to measure the reaction end products. It proved to be a valuable technique in combination with other analytical methods for determination of various carbohydrates. GI showed positive activity with glucose, fructose, xylose and L-sorbose but none with mannose, galactose, lactose, maltose, melibiose and cellobiose. Lactase was active on maltose, cellobiose, raffinose, lactose and sucrose but not with maltiol, melibiose or melezitose. Whey proteins were removed either by ultrafiltration or heat precipitation. This deproteinized whey was treated with the two enzymes to produce a syrup composed mainly of galactose, glucose, fructose and small amounts of oligosaccharides. The syrup had a predominantly sweet taste with a slight salty attribute. The proper utilization of whey lactose has potentially valuable features in the production of a sweetening ingredient for foods. This is especially true after the lactose has been hydrolyzed by lactase and then the glucose in the hydrolyzate isomerized to fructose with glucose isomerase.
Degree ProgramNutritional Sciences