A novel method for continuous production of cyclodextrins using an immobilized enzyme system

Abstract

Abstract Selected specific α‐amylase and glucoamylase enzymes were immobilized and combined with immobilized cyclodextrin glycosyltransferase to continuously produce cyclodextrin (CD). The liquefied starch was cyclized to CD by ICGTase and then treated by immobilized α‐amylase and glucoamylase to contain CD and glucose only. β‐CD and soluble CD (α‐ and γ‐CD) in the final CD solution could be easily separated. The pH‐activity curve, temperature‐activity curve, batch re‐usability and continuous operation stability of immobilized enzymes were discussed. The continuous production of CD by an immobilized enzyme system was also reported. The optimal conditions for using immobilized α‐amylase and glucoamylase simultaneously were 40°C and pH 4.5 adjusted by 1 mol dm −3 HCl/NaOH. A 70% yield of CD could be obtained from 1% (w/v) of liquefied starch under continuous operation at 0.055 h −1 space velocity, and almost all the oligosaccharides (β 98%) were converted to glucose. In this study, the separation of α‐CD, γ‐CD and glucose, using organic solvent from the final product after precipitating β‐CD, was also investigated.