Complexation of imazalil with b-cyclodextrin, residue uptake, persistance and activity against Penicillium decay in citrus fruit following postharvest dip treatments

A method for the inclusion of imazalil (IMZ) in the b-cyclodextrin (bCD), structural characterisation of the inclusion complex and its antifungal activity against Penicillium digitatum and P. italicum assessed by in vitro and in vivo tests are reported. According to the starting stoichiometry of bCD with respect to IMZ, an equimolar ratio b- cyclodextrin-IMZ (bCD-IMZ) was detected by 1H NMR. All fungicide treatments showed a comparable efficacy against decay in grapefruit and oranges, whereas treatment in lemons at 250 mg/L a.i. of heated fungicides had higher suppressive effects against decay than unheated chemicals having equal a.i. concentrations, and comparable activity at 1200 mg/L IMZ at 20 °C.