Ultrasonic preparation of citral/hydroxypropyl-β-cyclodextrin inclusion complex: Application as a potential antifungal preservative in strawberry storage

In this study, an inclusion complex (IC) of citral (CIT) within hydroxypropyl- β -cyclodextrin (HP β CD) was prepared by ultrasound technique. The structural characterization, thermal stability, phase solubility, antifungal properties and applications of CIT/HP β CD-IC in strawberry storage were investigated. The results showed that CIT/HP β CD-IC was successfully formed and had better thermal stability than CIT only. The apparent stability constant and Gibbs free energy change of the inclusion process was determined to be 142.08 M −1 and −12.87 kJ mol −1 , respectively, by the phase solubility method. The in vitro antifungal tests demonstrated that the IC had a certain antifungal effect against Geotrichum citri-aurantii , with a significant inhibitory effect against the growth of Botrytis cinerea and Alternaria alternata at concentrations above 5 mg mL −1 . Additionally, the treatment of CIT/HP β CD-IC on strawberry effectively reduced the decay rate and decrease of weight loss, soluble solids, firmness, and pH, thereby extending the shelf life. This research indicated that the ultrasonically synthesized CIT/HP β CD-IC effectively improved the water solubility and stability of CIT and could be utilized as an antifungal preservative for storage and preservation of strawberry, and potentially other fruits and vegetables.