反应详情

6100 units of glucoamylase of Asp. niger origin were added to 5 ml of a reaction mixture of a citric acid-sodium citrate buffer (pH 4.5) containing 10% glucose and 30% fructose, and a reaction was carried out at 65° C. overnight. The yield of isomaltulose formed during the reaction was 46% in relation to the glucose added. Note, the isomaltulose was determined according to the following procedure: The reaction mixture was filtrated by a ultrafiltration membrane to eliminate proteins, and the filtrate was diluted 6 to 10 fold. One μl of the diluted sample was spotted on a thin layer Kiesel Gel 60F254 plate (Merck), and the plate was subjected to two-dimensional thin layer chromatography using, as a developing solution, a mixture of methyl ethyl ketone, 2-propanol, acetonitrile, 0.5 M boric acid, and 0.25 M isopropylamine dissolved in acetic acid (2:3:1:1), and a mixture of methyl ethyl ketone, dipropyl ether, 2-propanol, pyridine, water and pheny boric acid (2:1:3:1:2.4). The plate was then treated with a mixture of 2% diphenylamine and 2% aniline dissolved in acetone, and phosphoric acid (1:1:8.5) to detect the isomaltulose by color development. Further, the reaction mixture was analyzed by high performance liquid chromatography using Shodex DC 613 column or Shodex SZ 5532 column (Showa Denko, Japan)