Flavor Specificities of Satsuma Mandarin Juice Extracted by a New-type Screw Press Extraction System

Dextransucrases from Leuconostoc mesenteroides NRRL B-1416 and B-1375 strains were purified to electrophoretically homogeneous preparations. After successive column chromatographies, the enzyme fractions were treated with endodextranase, then subjected to preparative polyacrylamide gel electrophoresis. The purified dextransucrase from each strain had a dimeric structure of molecular weight 130,000~133,000. Alkaline treatment (pH 10.5) dissociated these dimer forms into the respective monomer forms having molecular weight of 64,000~68,000. The two enzymes were closely similar to each other in optimum conditions and thermal and pH stabilities. The purified B-1416 enzyme was activated 4.35-fold by the addition of exogenous dextran (0.5%), while the B-1375 enzyme was activated 2.76-fold. In the absence of exogenous dextran, both enzymes gave 5~10 min lag periods for reaction, which were abolished by the clinical dextran.