N.G. Gulyuk, T.S. Puchkova, D.M. Pikhalo, Y.I. Komarov
All-Russia Research Institute for starch products, Russia, Moscow region, Kraskovo
E-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.
Summary. The results of studies of different methods of products purification after cyclization to produce beta-cyclodextrin (beta-CD), which had safe residual amount of complexant trichloroethylene, are stated in this article. The objects of the research were cyclodextrins (CD) – cyclic compounds that consisted of 6, 7, and 8 glucopyranose units, formed in a ring (alpha-, beta- and gamma-CD respectively). Beta-CD was produced from amylopectine starch under laboratory conditions. Gelatinization and partial dilution of starch were made using amylolytic enzyme preparation “BAN 480L” at dosage 0.2g/kg dry substances of starch. Conditions of hydrolysis were: concentration of starch suspension 30±0.2 %; treatment at a temperature 83±2 deg and further at a temperature 115±5 deg during 30 min. Then separation of fatty-protein suspension was made. Cyclization process was carried out using the preparation of cyclo-dextringlucanotransferase (CGT-ase) “Toruzym 3.0L” and compexant trichloroexthylene. Mixture was maintained at mixing and at a temperature 50±2 deg during 48 hours. Crystals of the complex beta-CD-trichloroethylene formed in the product. The residual amount of trichloroethylene was determined in samples of beta-CD using gas chromatograph with thermosorption GC-1010+. In order to reach safe quality of CD on complexant content after cyclization it is enough to boil it. At that the content of trichloroethylene in beta-CD is no more than 0.005 mg/kg, the same value as in the standard imported sample. The proposed method of beta-CD purification is the dissolution of crystals of complex cyclodextrin-tricholoroethylene after cyclization at heating, boiling during 20 min with further filtration, concentration, crystallization, centrifugation and drying.
Keywords: beta-cyclodextrin, purification, solvent technology, cyclodextringlucanotransferase (CGT-ase), complexing compound, trichloroethylene.