Preparation, Isolation And Application Of Maltosyl(α1â†'6)β-Cyclodextrins

β-Cyclodextrin (β-CD) has a medium intramolecular cavity of a cylindrical shape. It hasbeen used as complexing agents for the stabilization of oily unstable substances and for themodification of the physical properties of insoluble and volatile materials such as flavors, whichis therefore widely used in the food industry. However, β-CD has low solublilities in water.Maltosyl(α1→6)-β-Cyclodextrins(M-β-CDs) have extremely highly water solubility and can bemore safely and widely used in food industry. Analysis, synthesis, purification and application ofM-β-CDs were studied systemically in this paper.1. M-β-CDs synthesized from maltose and β-CD using Bacillus acidopullulyticusPullulanase(EC3.2.1.41) were qualitatively analyzed by paper chromatogram and TLC.Pullulanase hydrolysis-Somogyi method was used to quantify M-β-CDs on the basis of TLCqualitative analysis. The average value of the recovery for M-β-CDs measurement was(98.2±1.30)% with 1.30% of RSD (n=3). M-β-CDs were analyzed by HPLC on a columnHypersil NH2 using acetonitrile-water as the solvent system.2. Effect of pH and temperature on the pululanase was studied. To optimize the conditionsof the reaction, single factor test and orthogonal experiment design methods (L9 (34) ) wereapplied to analyze the influence of each factor given below. Experimental results indicated thatthe enzyme dosage significantly affected the translation ratio of β-CD.The optimum combiningconcentration of maltose and β-CD was 75% (w/w). The molar ratio of maltose to β-CD wasabout 18:1, and the amount of pullulanase was 200U/g β-CD. The optimum pH and temperatureof the reaction were about 4.0 and 70℃, respectively. Under this condition, the translation ratioof β-CD was more than 40%.3. Nanofiltration (NF) of M-β-CDs solution was studied with NE-1812 membrane(MWCO200～400) by investigating the permeation flux and the rejection of maltose. Whentemperature and pressure increased, the permeation flux rose slowly. The permeation fluxclimbed to the maximum at 40℃ and 0.5Mpa. When temperature went up, the rejection ofmaltose went down slightly;when pressure increased, the rejection of maltose went up slightly.The rejection of maltose went up to 93% at 40℃ and 0.5Mpa. The mass concentration of samplefrom 2g/L to 10g/L didn't affect notably the permeation flux and the rejection of maltose.4. The removal of maltose by Active Carbon Chromatography was studied. Maltose waseliminated at the mass concentration of 33% by 10%-20%-40% ethanol grads elution at1mL/min elution rate. Maltose went down to 2% with 40% ethanol elution. Sephadex G-15 silicacolumn was used to purify M-β-CDs at the mass concentration of 2% by water elution at0.2mL/min elution rate.5. The inclusion compound of vanillin with G2-β-CD was prepared, and its structuralcharacterization was studied by UV,IRand DSC. Phase solubility diagram method demonstratedthe molecular ratio of Vanillin to G2-β-CD in the inclusion compounds was 1:1, and theinclusion compounds constant was 1806.4L/mol.6. The change of the inclusion compounds of vanillin after preservation or bake showed theinclusion compounds of vanillin with β-CDs or G2-β-CD were slowly released in foodprocessing, and the retainment time of its fragrance prolonged so that the loss of vanillinfragance would reduce. The stability of the inclusion compounds was significantly increased forformation of the inclusion compounds.