Complexation of allyl isothiocyanate by α- and β-cyclodextrin and its controlled release characteristics

The complexation of allyl isothiocyanate (AITC) by α- and β-cyclodextrin (CD) and its controlled release characteristics were investigated in this paper. Almost 100% of inclusion capacity was achieved at the AITC/CD molar ratio of 2:1 using a coprecipitation method, combined with water washing. The controlled release behaviour of the incorporated AITC was significantly affected by relative humidity (RH) and the type of CD. The release was accelerated with increased RH, and the release rate of AITC in the α-CD-AITC complex was much slower than that in the β-CD-AITC complex. Subsequent analysis with GC demonstrated that the headspace concentration of AITC over β-CD-AITC complex in a hermetical system was significantly dependent on RH, and could finally be at a different equilibrium level at various storage times.