Ultrasound-mediated molecular self-assemble of thymol with 2-hydroxypropyl-ß-cyclodextrin for fruit preservation.

In this study, the inclusion complex (IC) of thymol with 2-hydroxypropyl-ß-cyclodextrin (HPßCD) was fast synthetized by ultrasonic technology and its antifungal activities were evaluated. The thymol/HPßCD-IC was characterized by UV-vis absorption spectroscopy, fluorescence emission spectroscopy, powder X-ray diffraction, FT-IR, 1H-NMR, TGA and DSC. The phase solubility studies proved that the aqueous solubility of thymol was significantly improved by forming the inclusion complex with HPßCD, and the thermal stability analysis showed that thymol/HPßCD-IC had a better thermal stability than pure thymol. The in vitro antifungal activities of thymol/HPßCD-IC against Botrytis cinerea, Penicillium digitatum and Alternaria alternata were significantly improved compared with pure thymol. Furthermore, the gray mold rot of tomatoes was evidently inhibited by thymol/HPßCD-IC treatment in vivo study. Therefore, the complexation with HPßCD assisted by ultrasound is a promising approach to solubilize and stabilize thymol for application as an antifungal agent in fruit preservation.