title: Conversion of glucose in lactase-hydrolyzed whey permeate to fructose with immobilized glucose isomerase.
abstract: The maximum conversion of glucose to fructose in lactase-hydrolyzed whey permeate by glucose isomerase was approximately 52% at .1 g enzyme/ml substrate after 7 h incubation at 60 degrees C. Removal of minerals from the substrate was essential for enzyme activity. The dependence of the enzyme on Mg++ and Co++ for activity in the presence of high ash concentration was demonstrated. Optimum Mg++ and Co++ additions were 250 and 100 ppm, respectively. The isomerization reaction was enhanced more when both 100 ppm Mg++ and 50 ppm Co++ were added. Hydrolyzed isomerized lactose whey syrup with sweetness equivalent to sucrose was successfully produced through enzymatic isomerization of glucose in lactase-hydrolyzed whey permeate after supplementation with pure glucose. Fructose in hydrolyzed isomerized lactose whey syrup was effectively separated from other sugars by Dowex 1X8-200 anion exchange resin in the bisulfite form.
mesh_terms: D019747:Aldose-Ketose Isomerases; D000818:Animals; D002238:Carbohydrate Epimerases / Q000378:metabolism*; D002417:Cattle; D003035:Cobalt / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005632:Fructose / Q000378:metabolism*; D005696:Galactosidases / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D066298:In Vitro Techniques; D007785:Lactose / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D008892:Milk / Q000378:metabolism*; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D005632:Fructose; D003035:Cobalt; D005696:Galactosidases; D001616:beta-Galactosidase; D002238:Carbohydrate Epimerases; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase; D008274:Magnesium; D005947:Glucose; D007785:Lactose